August 21, 2007 at 1:49 am #8115kirusabiParticipant
Is there any evidence on the test results of brains from the three main races? Due to a study that equates brain size to IQ level it has been assumed that blacks are less intelligent than whites and whites less intelligent than (mongoloid) Asians. And has anyone been able to compare the brain size of (Australoid) who have the lowest found IQ of any racial group to that of the other three groups?
IQ levels indefinitely vary between races. This has been reinstated in theories like those in the Belle Curve (not written by persons who had extensively studied in that field nor compared their findings with fellow scholars before publishing) where adults were tested in the three racial categories and it was found that blacks often had an IQ below 90 while the other two had 100 and higher on average.
However, another study was conducted, based on the belief that social stigmas play a role on IQ test results. To help demonstrate this tests were carried out on children at the age of 4, with blacks having the highest IQ, then mixed, then white.
However, the children reverted to the black lowest and white highter than blacks ‘routine’ at a later age.
The white brain is heavier and larger than brains of blacks. However the brains tested were adult brains. What puzzled me, is that further study of intelligence levels has led many to believe that based on this evidence brain size equates IQ. If this is true, where are the brain size tests for the 4 year olds?
I would assume that the black 4 year old would have had a smaller brain than that of the white child. However, I have not been able to come accross any such studies, to help me verify my belief. It is common knowledge that black children develop at a faster rate than whites, does this mean the black brain is larger than the white brain at the age of 4?
If it is shown that the brain of 4 year old children or children within that range, of different races have comparable brain sizes with that of their adult counterparts, it will debunk the notion that brain size determines intelligence level and help to dissolve the idea that IQ tests accurately measure intelligence.
If you have any information on such studies on brain sizes within the toddler ages between races, please post reference.
August 21, 2007 at 9:30 am #75339kotoreruParticipant
Mmmm my favourite kind of controversial question!
August 21, 2007 at 5:53 pm #75342mithParticipant
I forgot the name but this one guy did lots of brain measurements back in like the 1900’s using buckshot. He ran into a bit of trouble explaining why australian skulls were bigger. Also he compared female to male brains without compensating for body size.
August 22, 2007 at 2:17 am #75353DarbyParticipant
It’s interesting how, almost always, these studies favor the group the researchers belong to. And they tend to define "intelligence" in a way that favors those groups.
Size only somewhat correlates to potential – small differences, such as in the ranges found among human groups, don’t reach statistical significance. Heck, on a pure size basis, the Neanderthals had it over us sapiens.
August 22, 2007 at 4:07 pm #75366david23Participant
You know it’s these types of tests that create racism and barriers between people of different backgrounds. If anything, why dont these people look at the culture, family background, and other factors.
September 8, 2007 at 3:52 am #75893Jedi of ZenParticipant
I remember reading somewhere once – I don’t recall where – that East Asians (ie, Japanese, Chinese, etc.) tend to have head sizes that are larger than those of all other races when compared *in proportion to body size*. In other words, the head makes up a slightly larger percentage of the body in Asians than it does in people of other races. I don’t know if that’s true or not, and it doesn’t necessarily mean that the brains are actually larger, but it was an interesting statement.
But regardless of the IQ question, it is already well established within the medical field that there are genetic differences between races, as evidenced by the likelihood of certain racial groups to develop certain kinds of diseases that can only be acquired primarily by genetic transmission. Example – Tay-Sachs disease is far common among Ashkenazi Jews than among the general population.
April 15, 2008 at 12:50 am #83380bluecafe669Participant
RESEARCH SHOWS BLACKS TO HAVE LARGER BRAINS
The majority of empirical studies on the matter of racial differences in Brain size suggest that blacks have larger brains than do others groups. Brain sizes vary considerably within any species, but this variation is not usually related to intelligence. Instead, it correlates loosely with body size: large people tend to have larger brains (Gould, 1981). As a result, women on average will have smaller brains than men (Peters, 1991). However, this does not indicate that the level of male intelligence is higher than female intelligence; Neanderthals had on average larger brains than do anatomically modern humans (Tattersall, 1995; Gould, 1981) but most would agree that they were considerably less intelligent than Homo sapiens (Tattersal, 1995, 2004; Gould, 1981; Mithen 1998).
Tobias (1970) compared 7 racial and national groups in a study on brain size, in which he reported that the brain size of American blacks was larger than any white group, (which included American, English and French whites) except those from the Swedish sub sample (who had the largest brains of any of the groups measured), and American blacks were also estimated to have some 200 million more neurons than American whites (See Tobias 1970; Weizmann et al. 1990). While Gould (1981) discovered upon recalculating Morton’s skull data that the skulls of blacks in his sample were on average larger than those of whites. Morton included in his sample of black skulls more females than he included in the white sample. After correcting this error it was shown that the black sample had larger skulls (and presumably, larger brains) than did whites.
Interestingly, during the time periods in which the data for the above mentioned studies was collected anthropomorphic research has shown that blacks were on average physically smaller in stature than whites and received poorer nutrition (e.g. Alan, 2006). Indicating that in spite of relatively lower anthropomorphic measurements, blacks still demonstrated larger brain volume.
Other physical Anthropological research has shown that the skulls of Sub-Saharan Africans are generally wider and more robust than that of European/North African samples. For example sub-Saharan specimens show a generalized vertical facial flattening, with consequent widening of the entire structure (Bruner and Manzi, 2004). This pattern involves interorbital and orbital enlargement, widening and flattening of the nasal bones and aperture, maxillary development and upper rotation (Ibid). Keita (2004) found that European crania, relative to sub-Saharan African crania tend to have narrower faces in relationship to vault length. In this study significant variation among all measured groups was found, with African samples showing the most variation.
Genetic studies of human brainsize have discovered two genes that when mutated can result in a severely reduced brain volume, or ‘Autosomal recessive primary microcephaly’. The gene microcephalin (MCPH1) regulates brain size during development and has experienced positive selection in the lineage leading to Homo sapiens (Zhang, 2003; Evans et al, 2005). Within modern humans a group of closely related haplotypes, known as ‘haplogroup D’ arose from a single copy at this locus (Evans, 2006). Globally, D alleles are young and first appeared about 37,000 years ago; with high frequency haplotypes being rare in Asia, and particularly Africa. The highest frequencies are seen in Europe/Eurasia. The second microcephalin gene, ‘ASPM’ (abnormal spindle like Microcephaly associated), went an episode of positive selection that ended some time ago (between 6–7 million and 100,000 B.P.), with newer D variants showing positive selection arising about 5,800 years ago (Evans et al, 2005; Zhang, 2003).
Microcephaly genetic researchers believe that D alleles may have first arisen in an archaic homo species about 1.1 million years ago before introgression into modern Homo sapien sapiens about 37, 000 years ago; possibly as the result of interspecies breeding (Evans et al, 2006). In fact, microcephalin shows by far the most compelling evidence of admixture among the human loci examined thus far (Evans et al, 2006). Modern humans arose only 100,000 years ago in Africa (Horan et al, 2005), which would make D alleles more than 1million years “older” than modern humans, and certainly very primitive by any stretch.
Normal D variants of both ‘MCPH1’ and ‘ASPM’ genes have been shown to have mild affects on human brainsize with empirical evidence demonstrating the alleles to reduce brain volume, slightly (Woods et al, 2006). For example, each additional ASPM allele was associated with a non significant 10.9 cc decrease in brain volume. For MCPH1, each additional allele was associated with a non significant 19.5 cc decrease in brain volume (Woods et al, 2006).
While selective pressure in favor of smaller brain volume might seem counterintuitive, it should be noted that the fossil records suggest that brain size in humans – particularly Europeans – has decreased over the past 35,000 years, and on through the Neolithic period (Frayer, 1984; Ruff et al, 1997; Woods, et al, 2006). Interestingly, the selected variant of MCPH1 is thought to have arisen about 37,000 years ago (Evans et al, 2006) making it a candidate gene responsible for this general decline (Woods et al, 2006), while the ASPM variant is thought to have arisen only 5,800 years ago. These archaeological changes in brain size are paralleled by changes in body size (Ruff et al, 1997; Woods et al., 2006), and it is possible that decreases in brain size may have exerted selective pressure for corresponding decreases in body size in Europeans (Ruff et al, 1997; Frayer, 1984; see also, Woods et al., 2006).
The rate of selection for these particular variant MCPH1 and ASPM alleles might also indicate that the genes are relatively unexpressed in the human brain, outside of causing ‘Autosomal recessive primary microcephaly.’ In one study it was shown that genes with maximal expression in the human brain tend to show little or no evidence for positive selection (Nielsen et al, 2006). For example, the microcephaly genes in question have also been implicated in the development of breast cancer (Xu et al, 2004), and other non brain related conditions (Trimborn et al, 2004). Implying that the mild brain volume reductions observed with each additional variant of ASPM and MCPH1 may in fact be adaptively unimportant. It should be further noted that one microcephalin gene (CDK5RAP2) has shown evidence of positive selection in West African Yoruba (Voight, 2006; bond et al, 2005), however, this gene at the MCPH3 locus has been least involved in causing a microcephalin phenotype (Hassan et al, 2007), and is not believed to have arisen in an archaic homo species.
S.O.Y. KEITA (2006) in his principal components analysis on male crania from the northeast quadrant of Africa and selected European and other African series found no consistent size differences in the skulls he measured. Stating: “The plots are immediately striking in that sharp patterns of segregation of individuals by group origin do not emerge in the two dimensional plots. It is striking how much ‘‘size’’ varies by individual within the European and African regions, assuming that PC 1 captures primarily this quality; Bergman’s rule is not demonstrated in these data in any easily recognizable way, since individuals from all regions exhibit variation.” Herskovits’s (1930) data also suggest that there is no consistent Black/ White difference with respect to stature or crania.
Cernovsky (1990), however, reported that American blacks were superior in brain weight when compared with American whites. It is also known that the largest portions of the human brain are devoted to sensory and motor functions, which would mean that people with especially acute senses or strong motor skills can be expected to have larger brains than do others (Allen, 2002). It has been shown in several studies that blacks in general possess superior motor skills when compared to whites (Super, 1976; Wilson 1978; DiNucci, 1975); some believe that this may be the result of environmental and cultural factors (Super, 1976). The overall implications are the same, however, and suggest that blacks have larger brains.
Testosterone, Brain size and Penis size…?
Some of the more desperate claims for racial differences in brain size are accompanied by unusual arguments suggesting racial differences in penis size (that they are inversely correlated). Thorough investigation of the formal neuroscience, anthropology, paleontology, anatomy, physiology, and ‘sex psychology’ literature reveal that legitimate references to this – ridiculous (?) – notion are not only remote, but in fact, “nonexistent.” The development and size of one’s penis tend to be controlled by testosterone levels during puberty; and it is testosterone (and body size) that determine penis size. Testosterone: “Primary male hormone, causes the reproductive organs to grow and develop; responsible for secondary sexual characteristics, and promotes erections and sexual behavior.” Definition from: University of Michigan comprehensive Cancer Center; Fertility & Cryopreservation Glossary.
With this in mind; employing elementary logic one may safely arrive at the conclusion that because men tend to have dramatically higher levels of testosterone than do women (about 10 times the level), and on average have larger brains (due mostly to body size); that testosterone not only increases body and penis size, but also brain size! In fact, the relationship between brain size and testosterone is one of common knowledge, and is well documented in the literature (e.g. Solms and Turnbull, 2002).
Moreover, low testosterone has been associated with smaller penises and testes, failure to go through full normal puberty, poor muscle development, reduced muscle strength, low interest in sex (decreased libido), osteoporosis (thinning of bones common in whites and Asians), poor concentration, difficulty getting and keeping erections, low semen volume, longer time to recover from exercise, and easy fatigue, in men (McLachlan and Allan, 2005). On the flipside, high testosterone has been associated with improved health, superior motor abilities, increased reproductive value (in men), increased mental focus, larger brain volume, superior bone density and “boldness” (Dabbs and Dabbs, 2000; Solms and Turnbull, 2002; ).
It has also been documented by prostate cancer researchers that American blacks may possess levels of testosterone that are as much as 10% higher than American whites (Ross and Henderson, 1994; Bernstein et al, 1986; Ross et al, 1995), while East Asians have been shown to possess lower levels.
Alan S.A. (2006). African-American and White living standards in the 19th centrury American south; a biological comparison. CESifo Working Paper No. 1696
Allen B.P. (2006). If No “Races,” No Relevance to Brain Size, and No Consensus on Intelligence, Then No Scientific Meaning to Relationships Among These Notions: Reply to Rushton11. General Psychologist, Summer, 2003 Volume 38:2 Pages 31-32.
Bernstein L, Ross RK, Judd H, et al (1986). Serum testosterone levels in young black and white men. J Natl Cancer Inst 76:45—48, 1986
Bond J, Roberts E, Springell K, Lizarraga SB, Scott S, et al. (2005) A centrosomal mechanism involving CDK5RAP2 and CENPJ controls brain size. Nat Genet 37: 353–355.
Bruner E., Manzi G. (2004).Variability in facial size and shape among North and East African human populations. Ital. J. Zool., 71: 51-56 (2004)
Cernovsky Z.Z. (1990). Race and Brain Weight: A note on Rushton’s conclusions. Psychological Reports 66:337-38
Dabbs,J.M, Dabbs M.G. (2000). Heroes, Rogues and Lovers: Testosterone and Behavior. McGraw-Hill Companies (July 25, 2000)
Douglas B. (2008). Race, Intelligence and IQ: Are People of African Decent More Intelligent? Africaresource: educational, arts and research materials.
DiNucci, James M. (1975). Motor Performance Age and Race Differences between Black and Caucasian Boys Six to Nine Years of Age. The ERIC database, an initiative of the U.S. Department of Education. 1975-02-00
Evan P., Mekel-Bobrov N., Vallender E., Hudson R., Lahn B., (2006). Evidence that the adaptive allele of the brain size gene microcephalin introgressed into Homo sapiens from an archaic Homo lineage. 18178–18183, PNAS November 28, 2006, vol. 103, no. 48
Frayer, D.W. (1984). In The Origins of Modern Humans: A world survey of the Fossil Evidence (eds Smith, F.H. & Spencer, f.) 211-250 (Liss, New York, 1984)
Gould, S. J. (1981). Mismeasure of Man. New York: Norton.
Hassan M.J., Khurshid M, Azeem Z., John P, Ali G., Chishti M.S. and Ahmad W. Previously described sequence variant in CDK5RAP2 gene in a Pakistani family with autosomal recessive primary microcephaly. BMC Medical Genetics 2007, 8:58
Horan R.D., Bulte E., Shogren J.F. (2005). How trade saved humanity from biological exclusion: an economic theory of Neanderthal extinction. Journal of Economic Behavior & Organization Volume 58, Issue 1, September 2005, Pages 1-29
Mithen, S., 1998 (Ed). Creativity in Human Evolution and Prehistory, London: Routledge
Murphy, N. B. (1968). Carotid cerebral angiography in Uganda: review of boo consecutive cases. East African M. 7.,1968,45,47-60.
Nielsen,R., Bustamante,C., Clark,A.G., Glanowski,S., Sackton,T.B., Hubisz,M.J., Fledel-Alon,A.,
Tanenbaum,D.M., Civello,D., White,T.J., et al. (2005). A scan for positively selected genes in the genomes of humans and chimpanzees. PLoS Biol. 3,
Ross, R.K., Coetzee, G. A., Reichardt, J., Skinner, E, and Henderson, B.E. (1995). Does the Racial-Ethnic Variation in Prostate Cancer Risk Have a Hormonal Basis? Cancer, Volume 75, Issue S7 (p 1778-1782)
Ross R.K., Henderson B.E. (1994). Do diet and androgens alter prostate cancer risk via a common etiologic pathway? / Natl Cancer lnst 1994; 86:252-4.
Ruff C.B., Trinkaus E., and Holliday T.W. (1997). Body mass and encephalization in Pleistocene Homo. Nature Vol. 387, 8 May 1997
Solms M. and, Turnbull O. (2002). The brain and the inner world. Other Press, New York
S.O.Y. KEITA (2004). Exploring Northeast African Metric Craniofacial Variation at the Individual Level: A Comparative Study Using Principal Components Analysis. AMERICAN JOURNAL OF HUMAN BIOLOGY 16:679–689 (2004)
Super, C. M. (1976). Environmental effects on motor development: The case of African infant precocity. Developmental Medicine and Child Neurology, 18, 561–567.
Tattersall, I. and J.H. Schwartz (2000). Extinct Humans, New York: Westview Press.
Tattersall (1995) The Fossil Trail (Ev)
Tobias, T.V. (1970). Brain Size, Grey matter and Race – Fact or Fiction? American Journal of Physical Anthropology 32:3-26
Trimborn,M., Bell,S.M., Felix,C., Rashid,Y., Jafri,H., Griffiths,P.D., Neumann,L.M., Krebs,A., Reis,A., Sperling,K., et al. (2004). Mutations in Microcephalin cause aberrant regulation of chromosome condensation. Am. J. Hum. Genet., 75, 261-266.
Voight BF, Kudaravalli S, Wen X, Pritchard JK (2006) A map of recent positive selection in the human genome. PLoS Biol 4(3): e72
Wilson A. (1978). Developmental Psychology of the Black Child. Africana Research Publications (December 1978).
Woods R., Freimer N., Young J., Fears S, Sicotte N., Service S., Valentino D., Toga A., Mazziotta J. (2006). Normal Variants of Microcephalin and ASPM Do Not Account for Brain Size Variability. Human Molecular Genetics, Volume 15, Number 12, 15 June 2006, pp. 2025-2029(5)
Xu X., Lee J., and Stern D.F. (2004). Microcephalin Is a DNA Damage Response Protein Involved in Regulation of CHK1 and BRCA1. THE JOURNAL OF BIOLOGICAL CHEMISTRY Vol. 279, No. 33, Issue of August 13, pp. 34091–34094, 2004
Zhang J. (2003). Evolution of the Human ASPM Gene, a Major Determinant of Brain Size. Genetics 165: 2063–2070 (December 2003)
April 15, 2008 at 12:38 pm #83388
There was a BBC document recently, where they studied people with very high IQ and comapred them among one another, as well as with some normal IQ persons. One factor they measured was the brain size (as well as the amount of grey matter), and surprisingly the guy who topped the IQ charts and other intelligence tests had the smallest brains and lowest amount of grey matter in the whole test population.
The brain scientists reasoned that his IQ was actually due to the extraordinarily efficient "wiring" of his neurons, and that the brain size had very little to do with intelligence.
Oh, and my personal view regarding this topic:
there probably are differences in intelligence between races as well as between sexes. However, since cultural factors and the heterogeneity of human populations are so immense, and since even the term "intelligence" cannot be exclusively defined, I don’t think the issue can be proven. And who is smart and who is dumb? I don’t know. The blacks are superior physically (they run faster, hit harder and slam dunk in a way no white or yellow man will ever do :P) – they could as easily be smarter than the whites and the yellows. It just isn’t as straightforward to prove or disprove as is 100 m sprint.
And the whole topic is a bit trivial anyway, since it has been proved countless of times that each race and both genders can produce great brains and great athletes, and that majority of us, regardless of the race or sex, behave like the planet-destroying useless pests we are. In the end, what good does it do to prove that the race A is 0.03 % more intelligent than races B and D, and that this piece of knowledge does not make any difference anyway?
-White boy from the North
May 16, 2008 at 12:13 am #84126
The first edition of The Mismeasure of Man appeared in 1981 and was quickly praised in the popular press as a definitive refutation of 100 years of scientific work on race, brain-size and intelligence. It sold 125,000 copies, was translated into 10 languages, and became required reading for undergraduate and even graduate classes in anthropology, psychology, and sociology. The second edition is not truly revised, but rather only expanded, as the author claims the book needed no updating as any new research would only be plagued with the same philosophical errors revealed in the first edition. Thus it continues a political polemic, whose author engages in character assassination of long deceased scientists whose work he misrepresents despite published refutations, while studiously witholding from his readers fifteen years of new research that contradicts every major scientific argument he puts forth. Specific attention in this review are given to the following topics: (1) the relationship between brain size and IQ, (2) the importance of the scientific contributions of Sir Francis Galton, S. G. Morton, H. H. Goddard, and Sir Cyril Burt, (3) the role of early IQ testers in determining U.S. immigration policy, (4) The Bell Curve controversy and the reality of g, (5) race/sex/social class differences in brain size and IQ, (6) Cesare Lombroso and the genetic basis of criminal behavior, (7) between-group heritabilities, inter-racial adoption studies, and IQ (8) why evolutionary theory predicts group differences, and (9) the extent to which Gould’s political ideology has affected his scientific work.
"May I end up next to Judas Iscariot, Brutus, and Cassius in the devils mouth at the center of hell if I ever fail to present my most honest assessment and best judgment of evidence for empirical truth" (p. 39). So swears one Stephen Jay Gould, justifiably worried that his activist background may have tarnished his reputation for scholarship. Critical examination of the new edition of The Mismeasure of Man shows that, indeed, Gould’s resort to character assassination and misrepresentation of evidence have caught up with him.
Hailed in the popular media as the definitive deconstruction of the ‘myth’ that science is an objective enterprise, the original The Mismeasure of Man was in fact an ad hominem attack on eminent scholars, past and present, who have scientifically studied race, intelligence, and brain size. Despite the masses of empirical research using state-of-the-art technology published in highly prestigious journals that refute the obscurantist arguments Gould first served up in 1981, all the chapters of the initial edition have now been unapologetically regurgitated. Gould’s failure not only to conduct any empirical research of his own but to even acknowledge the existence of any and all contradictory data speaks for itself. Revealed political truth may abhor revision but science thrives on it. Scientist that he is, Gould may yet regret agreeing to produce this ‘revision’.
Rather than being appropriately revised, the original edition of The Mismeasure of Man has merely been expanded. Gould includes a 30-page preface on why he wrote the original and why the renewed interest in race, behavior, and evolution, required that he ‘revise’ it after 15 years, although he also maintains (p. 35) that his 1981 arguments needed no modification. Gould’s 1996 book also contains five end chapters including essays on J. F. Blumenbach, the 19th century German anthropologist who developed the first scientific system of racial hierarchy, and Gould’s own previously published reviews of Herrnstein and Murrays (1994) The Bell Curve.
After carefully reading the book, I charge Gould with several counts of scholarly malfeasance. First, he omits mention of remarkable new discoveries made from Magnetic Resonance Imaging (MRI) which show that brain-size and IQ correlate about 0.40. These results are as replicable as one will find in the social and behavioral sciences and utterly destroy many of Gould’s arguments. Second, despite published refutations, Gould repeats verbatim his defamations of character against long deceased individuals. Third, Gould fails to respond to the numerous empirical studies that show a consistent pattern of race differences in IQ, brain size, crime, and other factors that have appeared since his first edition went to press.
Brain-Size/IQ Relations: Where Was Gould During The Decade Of The Brain?
In the opening chapters, Gould charges 19th century scientists with ‘juggling’ and ‘finagling’ brain size data in order to place Northern Europeans at the apex of civilization, lower orders trailing behind in a great chain of being. He argues that, in effect, Paul Broca, Francis Galton, and Samuel George Morton, all erred in the same direction and by similar magnitudes. Implausibly, Gould asks us to believe that Broca ‘leaned’ on his autopsy scales when measuring wet brains by just enough to produce the same differences that Morton caused by ‘over-packing’ empty skulls using filler, as did Galton’s extra loose grip on calipers while measuring heads!
Later in the book, Gould attempts to discredit such 20th century luminaries as H. H. Goddard, Lewis Terman, R. M. Yerkes, Charles Spearman, Cyril Burt, Hans Eysenck and Arthur Jensen who, Gould claims, mean-spiritedly set out to measure IQ and fabricate its heritability. Gould specifically charges psychometricians with the sin of reification, that is, treating hypothetical constructs as though they were real entities. His major target is the general factor of intelligence (known as g). Contrary to Gould, every major study shows that different IQ tests tend to be significantly intercorrelated (Carroll, 1993) and that g is the ‘active ingredient’ in IQ predictions (Brody, 1992).
Gould’s omission of recent, devastatingly contradictory evidence constitutes at best shoddy and at worst dishonest scholarship. Even before Gould’s (1981) first edition, Van Valen (1974) had reviewed the literature and estimated an overall correlation of 0.30 between brain size and intelligence. Gould (1981) neglected to even mention Van Valens review. The 1990s have been called the ‘Decade of the Brain’ for good reason. Remarkable discoveries made using MRI confirm many of the relationships described by the 19th century visionaries defamed by Gould. Neither Gould nor his publisher show any scruples in releasing these chapters without the required revisions. Since Gould chose to withold this evidence from his extensive readership, allow me to reveal it. (For more detail, see the review by Rushton & Ankney, 1996).
The published research that most clearly shows the correlation between brain size and intelligence employed MRI, which creates, in vivo, a three-dimensional image of the brain. An overall correlation of 0.44 was found between MRI-measured-brain-size and IQ in 8 separate studies with a total sample size of 381 non-clinical adults. This correlation is about as strong as the relationship between socioeconomic status of origin and IQ. In seven MRI studies of clinical adults (N = 312) the overall correlation was 0.24; in 15 studies using external head measurements with adults (N = 6,437) the overall correlation was 0.15, and in 17 studies using external head measurements with children and adolescents (N = 45,056) the overall correlation was 0.21. The head size and brain size correlation with the g factor itself, which Gould would have you believe is a mere artifact, is even larger — 0.60! (Jensen, 1994; Wickett et al., 1996).
Further, the brain-size/IQ correlation is predictive from birth. The National Collaborative Perinatal Study analyzed data from 17,000 White babies and 19,000 Black babies followed from birth to 7 years (Broman et al., 1987). Head perimeters were measured at birth for all children. At age 7, head perimeters were remeasured and IQ assessed. For both the Black and the White children, head perimeter measured at birth significantly predicted head perimeter at 7 years, and head perimeter at both ages predicted IQ!
The first of these MRI studies were published in the late 1980s and early 1990s in leading, refereed, mainstream journals like Intelligence (Willerman et al., 1991) and the American Journal of Psychiatry (Andreasen et al., 1993). I know Gould is aware of them because my colleagues and I routinely sent him copies as they appeared and asked him what he thought! For the record, let it be known that Gould did not reply to the missives regarding the published scientific data that destroyed the central thesis of his first edition.
Further evidence of Gould’s method is the way the 1996 edition deletes the very section of the 1981 edition that discussed the brain-size/IQ relation. In the 1981 edition (pp. 108-111), Gould cited Jensen’s (1980) Bias in Mental Testing (pp. 361-362) in order to pooh-pooh Jensen’s report of a 0.30 correlation between brain-size and IQ and a table from Hooton (1939) which showed that average head sizes differed by SES. Gould (1996) gives no reason for making this selective cut, which would have appeared on page 140 of the new edition. I can only infer that when Gould read Jensen’s (1982) review of his book, which he mentions doing in the introduction, he realized that Jensen’s citation of the 0.30 correlation between brain size and IQ was based on Van Valen’s (1974) review and so could no longer be dismissed as just Jensen. I submit that Gould realized that repeating this section verbatim, given the weight of the new evidence, would destroy his entire thesis. Rather than revise his arguments in light of the truth, Gould chose to repeat them without change and to withold any evidence to the contrary. Both Gould and his publisher owe it to their readers to explain why this supposedly ‘new’ edition studiously avoids any mention of all the new evidence.
Is it reasonable to expect that brain size and cognitive ability are related? Yes! Haug (1987, p.135) found a correlation of 0.479 (N = 81, P<0.001) between number of cortical neurons (based on a partial count of representative areas of the brain) and brain size in humans. His sample included both men and women. The regression relating the two measures is: number of cortical neurons (in billions)= 5.583 + 0.006 (cm3 brain volume). According to this equation, a person with a brain size of 1,400 cm3 has, on average, 600 million fewer cortical neurons than an individual with a brain size of 1,500 cm3. The difference between the low end of the normal distribution (1,000 cm3) and the high end (1,700 cm3) works out to be 4.2 billion neurons. That amounts to 27% more neurons for a 41% increase in brain size. The best estimate is that the human brain contains about 100 billion (1011) neurons classifiable into perhaps as many as 10,000 different types resulting in 100,000 billion synapses (Kandel, 1991). Even storing information at the low average rate of one bit per synapse, which would require two levels of synaptic activity (high or low/on or off), the structure as a whole would generate 1014 bits of information. Contemporary supercomputers, by comparison, typically have a memory of about 109 bits.
On Character and Character Assassination
Gould’s faults extend well beyond sins of omission to include sins of commission. The ‘new’ edition repeats the same false accusations that have been well refuted since 1981. Thus, Gould leaves unmodified his denigration of Sir Francis Galton as a ‘dotty Victorian eccentric’ (p. 108) despite having been called to account for painting a thoroughly tendentious portrait by University of Cambridge statistician, A. W. F. Edwards (1983) in the London Review of Books. Edwards rightly excoriated Gould, as the author of a book full of references to correlation, regression (including multiple regression), principal components analysis, and factor analysis, for failing to inform his readers that this whole statistical methodology is derived from Galtons pioneering work on the bivariate normal distribution and linear regression.
Gould also repeats verbatim his (1981) claim that S. G. Morton (1799-1851), one of the giants of 19th American science, ‘unconsciously’ doctored his results on cranial capacity so as to prove Caucasian racial superiority, despite the fact that when J. S. Michael (1988) remeasured a random sample of the Morton collection he found that very few errors had been made, and that these were not in the direction that Gould had asserted. Instead, the errors were in Gould’s own work! Michael concluded that Mortons research "was conducted with integrity…(while)…Gould is mistaken" (p. 353).
Other refutations of Gould’s original edition of The Mismeasure of Man appeared in the 1987 and 1988 issues of the American Psychologist. Gould claimed to have detected "conscious skullduggery" in Goddard’s (1912) study of the heritability of feeblemindedness in the Kallikak family and alleged that Goddard’s photographs had been ‘phonied’ by inserting heavy lines to give the eyes and mouth a ‘depraved’, ‘sinister’, and ‘diabolical appearance’. However, not only was such retouching common during the period and thus betrays no evil intent (Fancher, 1987), but the retouched photographs actually strike judges (when empirically tested) as appearing kind (Glenn & Ellis, 1988).
Similarly, Gould repeats his trashing of Sir Cyril Burt’s reputation, citing the initial verdict against him by Hearnshaw (1977) and avoiding any mention of the new evidence that has since come to light. Recall that Burt (1883-1971) was the distinguished British educational psychologist who reported a heritability for IQ of 77% for identical twins reared apart. Subsequently, he was widely accused of fabricating his data. However, five separate studies of identical twins raised apart have now corroborated Burt’s finding (Jensen, 1992; see also Bouchard et al., 1990; Pedersen et al., 1992). The average heritability from these studies is 75%, almost the same as Burts supposedly ‘faked’ heritability of 77%. Moreover, two independently written, meticulously thorough books, one by Robert B. Joynson (1988) and the other by Ronald Fletcher (1991), have vindicated Burt and described how he was railroaded by those on both sides of the Atlantic dedicated to destroying hereditarian findings.
Early IQ Testers, Immigration, And The Holocaust
Gould’s most inflammatory allegation consists of blaming IQ testers for magnifying the toll of those lost in the Holocaust (p. 263). Here he has followed the lead of Leon Kamin’s (1974) The Science and Politics of IQ. The Kamin-Gould thesis is that early IQ testers claimed their research proved that Jews as a group scored low on their tests and that this finding was then conveniently used to support passage of the restrictive Immigration Act of 1924 which then denied entry to hapless Jewish refugees in the 1930s. Gould goes so far as to claim (1996, pp. 195-198; 255-258) that Henry H. Goddard (in 1917) and Carl C. Brigham (in 1923) labeled four-fifths of Jewish immigrants as "feeble-minded … morons".
The facts are very different. Goddard wanted to find out if the Binet test was as effective at identifying ‘high-grade defectives’ (the term then used for those with mental ages between eight and twelve) among immigrants as it was among native-born Americans. By 1913, Goddard had translated the Binet test into English and arranged, over a two-and-a-half-month period, for it to be given to a subset of Jewish, Hungarian, Italian, and Russian immigrants "preselected as being neither ‘obviously feeble-minded’ nor ‘obviously normal’" (Goddard, 1917, p. 244, emphasis added). Among this "unrepresentative" group (178 subjects in all), the tests successfully categorized 83% of the Jews, 80% of the Hungarians, 79% of the Italians, and 87% of the Russians. Goddard (1917) explicitly did not assert that 80% of Russians, Jews, or any immigrant group in general were feeble minded nor that the figures were representative of all immigrants from those nations. Nor did he claim that the feeblemindedness he was measuring was due to heredity. The vast majority of the many immigrants going through Ellis Island were never given mental tests. Nor was a random sample of any national group of immigrants ever tested. The only study by Goddard involving the testing of immigrants begins with the following sentence: "This is not a study of immigrants in general but of six small highly selected groups… "(1917, p. 243).
Gould’s account of Brigham’s (1923) A Study of American Intelligence is also misleading. Brigham examined the First World War intelligence tests given to 15,543 White officers, 93,955 White recruits, and 23,596 ‘Negro’ recruits. The White recruits were subdivided into 81,465 native born (‘Nordic’ in origin) and 12,492 foreign born (categorized by country of origin as being primarily ‘Nordic’, ‘Alpine’, or ‘Mediterranean’). Brigham found that U.S.-born White officers averaged a ‘mental age’ of about 17.3, U.S.-born White draftees about 13.3 years, foreign-born English speaking Nordics about 13.4 years, foreign-born non-English speaking Nordics about 12.6 years, foreign-born Alpines about 11.7 years, foreign-born Mediterraneans about 11.5 years, and Negroes about 10.7 years. Brigham made only passing reference to Jewish IQ (pp. 187-190) noting that no separate scores existed for them. But, by assuming that the proportions from the U.S. Census of 1910 were generalizable to his army recruits (implying that 50 percent of his Russian-born sample was Jewish, and that the Jewish subset scored about the same as other Russians), Brigham concluded that their mean mental age could be estimated at about 11.5 years. Brigham concluded that these data, taken at face value, did "tend to disprove the popular belief that the Jew is highly intelligent" (p. 190), but he immediately qualified this by noting that the standard deviation of the Russian sample was the highest of any immigrant group and that talent searches in New York and California schools often found high ability among Jewish children. Nonetheless, he did remark, somewhat snidely, that "the able Jew is popularly recognized not only because of his ability, but because he is able and a Jew" (p. 190).
For all their faults, the true story of the early IQ testers is a far cry from Gould’s attempt to label them as unindicted co-conspirators in genocide. What is especially vexing about Gould’s account is that he repeats it despite widely disseminated refutations. Historian of psychology Franz Samelson (1975, 1982) began the process of setting the record straight with his review of Kamin’s book in the journal Social Forces. Perhaps the most incisive of these refutations appeared in a paper by Mark Snyderman and the late Richard Herrnstein in the 1983 issue of the American Psychologist. Snyderman and Herrnstein fully corroborated Samelson’s conclusions, pointing out that the testing community in general did not view its findings as favoring restrictive immigration policies like those in the 1924 Act. As far as Snyderman and Herrnstein could ascertain from the records and publications of the time, Congress took virtually no notice of intelligence testing. None of the major contemporary figures in testing were called to testify, nor were any of their writings inserted into the legislative record.
In his 1981 book In Search of Human Nature, the eminent historian Carl N. Degler took Gould to task for ignoring contradictory information. Degler pointed out, for example, that it was the evidence of high IQs in Jews and Chinese in California that led Lewis Terman to strengthen his view that the low Black IQ was heritable. Degler also pointed out that although the comparatively high scores of Orientals did not prevent them from being excluded from immigration, such scores would embarrass any attempt to make IQ the basis for ethnic bias in immigration. Again, in 1992, the noted columnist Daniel Seligman debunked Gould’s anti-testing propaganda in his book A Question of Intelligence. Most revealing of Gould’s scholarship, perhaps, is that Herrnstein and Murray (1994) also highlighted the issue in a special boxed section on page 5 of The Bell Curve, a book that Gould reviewed (twice!). Did Gould overlook these refutations? Why did he not respond to them in his ‘revision’?
The early IQ testers were far more aware of the effects of environmental and cultural background on their test takers than Gould would have you believe. They clearly stated that many high-IQ groups had been excluded from the draft sample, including those in occupations exempted from the draft as being vital to the war effort. Gould acknowledges these facts (p. 252) but puts on the spin that if Yerkes (1921) knew of flaws in his massive monograph Psychological Examining in the United States Army, from which Brigham (1923) drew his data, this only made the conclusions even more obviously biased than they otherwise would have been.
The reality of g?
Eighty years of theoretical and applied progress, unrivalled in virtually any other field of psychology, have done nothing to diminish the fervor of Gould’s anti-psychometric zealotry. In his review of The Bell Curve, Gould (1996, pp. 370-376) charges Herrnstein and Murray (1994) with ‘disingenuousness’. First, Gould alleges disingenuousness of content, for he claims that The Bell Curve is really about race, but pretends to be about IQ. Second, he alleges there is disingenuousness of argument, for The Bell Curve fails to report openly the strength of statistical relationships. Finally, he claims there is disingenuousness of political program, for The Bell Curve attempts to justify cutting social programs while claiming to be in the tradition of Jeffersonian democracy.
Gould withholds from his readers that The Bell Curve is mainly an empirical work about the causes of social stratification and that it reached its conclusions only after fully analyzing a 12-year longitudinal study of 12,486 youths (3,022 of whom were African American) which showed that most 17-year-olds with high IQs (Blacks as well as Whites) went on to occupational success by their late 20s and early 30s whereas many of those with low IQs (both Black and White) went on to welfare dependency. The average IQ for African Americans was found to be lower than those for Latino, White, Asian, and Jewish Americans (85, 89, 103, 106, and 115, respectively, pp. 273-278). Failure to mention these data fosters the false belief that IQ tests are not predictive and are biased in favor of North Europeans.
In an afterword to the softcover edition of The Bell Curve, Charles Murray (1996) chides Gould and his reviews for being hopelessly out of date regarding the evidence for the biological basis of g and for dismissing as ‘trivial’ the predictive power of IQ in The Bell Curve sample. Murray invites Gould to "count the ways" in which g does in fact capture "a real property in the head". The higher the g loading of a subtest, the higher is its heritability, the higher the degree of inbreeding depression (an established genetic phenomenon) a test exhibits, the higher its relation to elementary cognitive tasks like reaction time, and the more it is related to physiological processes such as cortical evoked potentials and the brains consumption of glucose. Murray also accuses Gould of misleading readers by focusing on the R2 statistics given in the appendix, rather than on the IQ predictions given in the text. As Murray concludes "The relationships beween IQ and social behaviors that we present in the book are so powerful that they will revolutionize sociology" (p. 569).
Gould likes to leave his readers chanting the mantra that "g is nothing more than an artifact of the mathematical procedure used to calculate it". Jensen and Weng (1994) and Carroll (1995) provide detailed empirical and analytical demonstrations of the reality of g. Suffice to note for the purposes of this review that they find that g is remarkably robust and invariant across different data sets, different statistical procedures, or even simulated data, and that Gould avoids any mention of these studies.
Race and IQ: What Gould Doesnt Want You To Know
In his critique of The Bell Curve, Gould acknowledges (p. 369), and then quickly sidesteps the finding that Orientals have a small average IQ advantage over Whites and a large one over Blacks, despite being aware that The Bell Curve brought Richard Lynn’s (1991) detailed compilation of these data to wide attention. Because Gould dodged the issue allow me to address it. Lynn (1991, 1996) showed that, on average, Orientals score higher on tests of mental ability than do Whites, both within the U.S.A. and in Asia, whereas Africans and Caribbeans score lower. Oriental populations in East Asia and North America typically have mean IQs falling between 101 to 111. White populations in Europe, South Africa, Australasia, and North America have mean IQs of from 85 to 115, with an overall mean of 100. Black populations living south of the Sahara, in the Caribbean, in Britain, and in North America, average IQs of from 70 to 90.
Especially contentious was Lynn’s calculation of a mean IQ of only 70 for Black Africans living south of the Sahara. Many reviewers have expressed skepticism about such a low IQ, holding it impossible that, by European standards, 50 percent of Black Africa is ‘mentally retarded’. But a mean African IQ of 70 has been confirmed in three studies since Lynn’s review, each of which used Raven’s Progressive Matrices, a test regarded as an excellent measure of the non-verbal component of general intelligence and one not bound by culturally specific information. Kenneth Owen (1992) found it (a mean IQ of 70) in a sample of over 1,000 South African 13-year-olds, Fred Zindi (1994), a Black Zimbabwean, found it in a study of 12- to 14-year olds in Zimbabwe, and Richard Lynn (1994a) found it in a study of Ethiopian immigrants to Israel. In a reply to Leon Kamin regarding these data, Charles Murray (1995) wrote:" When data are as carefully collected and analyzed as these, attention must be paid" (p. 22).
Speed of decision making (reaction time) in 9- to 12-year olds, in which children decide which of several lights stands out from others, shows that the racial differences in mental ability are not restricted to paper and pencil tests. All children can perform the task in less than one second, but more intelligent children, as measured by traditional IQ tests, perform the task faster than do less intelligent children. Lynn (1991) found Oriental children from Hong Kong and Japan were faster on average in decision time (controlling for movement time) than were White children from Britain and Ireland, who in turn were faster than Black children from South Africa. Using the same decison time tasks, Jensen (1993) found the same racial ordering in California school children.
Race and Brain Size: What Gould Doesnt Want You To Know
It seems unlikely that Gould’s scornful remarks about early studies of racial differences in brain size were based on an objective assessment of the literature. First, investigation of the studies Gould does cite show him up to his usual tricks of hiding and distorting data. Second, although numerous modern studies have appeared since his 1981 edition went to press, he fails to make the corrections required by them or even to acknowledge their existence.
Consider, for example, a section titled "A Curtain Raiser With a Moral". In this, Gould (1996, 109-114) reviewed a technical debate over Black/White brain-size differences between Robert Bennett Bean (1906), a Virginia physician, and Franklin P. Mall (1909), Beans mentor at Johns Hopkins Medical School. Bean (1906) published a study finding that the weight of 103 American Negro brains at autopsy varied with the amount of Caucasian admixture, from 0 admixture = 1,157 grams, 1/16 = 1,191 grams, 1/8 = 1,335 grams, 1/4 = 1,340 grams, to 1/2 = 1,347 grams. Bean also reported that the 103 Negro brains were less convoluted than were 49 White brains and that Whites had a proportionately larger genus to splenium ratio (front to back part of corpus callosum), implying that Whites may have more activity in the frontal lobes which were thought to be the seat of intelligence. Mall (1909) disagreed and found that he was unable to replicate the results on genus/splenium ratios when he remeasured a subset of the brains under ‘blind’ conditions regarding the race of the brain. Gould elevated this disagreement on one of the findings into a morality play. (Mall "became suspicious"; "prior prejudice dictates conclusions"). What Gould neglects to tell us is that Mall himself (p. 7) reported a Black/White difference in brain weight of 100 grams and that he did not refute the data on racial admixture or on complexity of convolutions.
J. S. Michael’s (1988) revelation of Gould’s mistreatment of Samuel George Morton’s 19th century data has been described above. Nonetheless, Michael remained doubtful that Morton’s data could be used to examine race differences in brain size. Rushton (1989a), however, showed that Morton’s data, even as reassesed by Gould, indicated that in cubic inches, Mongoloids averaged 86.5, Caucasoids 85.5, and Negroids 83.0, which convert to 1,401, 1,385, and 1,360 cm3, respectively. To be absolutely clear there is no misunderstanding about these data and to allow readers to combine the subgroups in their own preferred ways, Table 1 presents Gould’s own retabulation of Morton’s data (1981, p. 66, Table 2.5; 1996, p. 98, Table 2.5). Gould dismisses these differences as "trivial". But, as noted, a difference of 1 cubic inch (16 cm3) in brain size translates into a very nontrivial millions of neurons and hundreds of millions of synapses.
Table 1. S.J. Gould’s ‘ corrected’ final tabulation of Morton’s assessment of racial differences in cranial capacity
Population Cubic inches Cubic centimeters
Native Americans 86 1410
Mongolians 87 1427
Modern Caucasians 87 1427
Malays 85 1394
Ancient Caucasians 84 1378
Africans 83 1361
Finally, consider the pattern of decreasing mean brain size going from East Asians to Europeans to Africans shown in Rushton’s (1989a) reanalysis of Gould’s retabulation of Morton’s data. This pattern has been corroborated since 1980 by three different techniques: wet brain weight at autopsy, volume of empty skulls using filler, and volume estimated from external head sizes. Recently, a fourth technique, Magnetic Resonance Imaging (MRI), has confirmed the White/Black difference. The preponderance of evidence from studies using different techniques, conducted by different researchers, on different samples, confirms the conclusion that the brains of Orientals and their descendants average about 17 cm3 (1 in3) larger than those of Europeans and their descendants whose brains average about 80 cm3 (5 in3) larger than those of Africans and their descendants.
Consider the following statistically significant comparisons (sexes combined) from recently conducted studies using the four techniques mentioned above. Using brain mass at autopsy, Ho et al. (1990) summarized data for 1,261 individuals. They reported a mean brain weight of 1,323 grams for White Americans and 1,223 grams for Black Americans. Using endocranial volume, Beals et al. (1984) analyzed about 20,000 skulls from around the world and found that East Asians, Europeans, and Africans averaged cranial volumes of 1,415, 1,362, and 1,268 cm3 respectively. Using external head measurements from a stratified random sample of 6,325 U.S. Army personnel, Rushton (1992) found that Asian Americans, European Americans, and African Americans averaged 1,416, 1,380, and 1,359 cm3, respectively. Using external head measures from tens of thousands of men and women from around the world collated by the International Labour Office, Rushton (1994) found that Asians, Europeans, and Africans averaged 1,308, 1,297, and 1,241 cm3, respectively. Finally, an MRI study in Britain found that people of African and of Caribbean background averaged a smaller brain volume than did those of European background (Harvey et al., 1994).
Contrary to most purely environmental theories, racial differences in brain size show up early in life. Data from the U.S. National Collaborative Perinatal Project on 19,000 Black children and 17,000 White children showed that Black children had a smaller head perimeter at birth and, although Black children were born shorter in stature and lighter in weight than White children, by age 7 ‘catch-up growth’ led Black children to be larger in body size than White children. However, Blacks remained smaller in head perimeter (Broman et al., 1987). Further, head perimeter at birth, 1 year, 4 years, and 7 years correlated with IQ scores at age 7 in both Black and White children (r = 0.13 to 0.24).
Sex Differences: What Gould Doesnt Want You To Know
An absolute difference in brain size between men and women has not been disputed since at least the time of Broca (1861). He assembled a series of 292 male brains and found an average weight of 1,325 grams, while 140 female brains averaged 1,144 grams, a difference of 181 grams. Gould claimed that the sex difference disappears when appropriate statistical corrections are made for body size or age of people sampled. However, when Gould used multiple regression to remove the simultaneous influence of height and age, he only succeeded in reducing the sex difference by one third, to 113 grams. Gould then invoked additional unspecified age and body parameters, claiming that if these could be controlled the entire difference would disappear.
David Ankney (1992) questioned Gould’s methodology. He reexamined autopsy data on 1,261 American adults (Ho et al., 1980) and found that at any given body surface area or height, mens brains are heavier than are womens brains. For example, among those who are 168-cm tall (5′ 7"; the approximately overall mean height for men and women combined), brain mass of men averages about 100 g heavier than that of women, whereas the average difference in brain mass, uncorrected for body size, is 140 g. Thus, only about 30% of the sex difference in brain size is due to differences in body size.
Ankney’s (1992) results were confirmed in the study of cranial capacity in a stratified random sample of 6,325 U.S. Army personnel (Rushton, 1992). After adjustment, via analysis of covariance, for effects of age, stature, weight, military rank, and race, men averaged 1,442 cm3 and women 1,332 cm3. This difference was found in all of 20 or more separate analyses performed to rule out any body-size effect (see Rushton, 1992; pp. 406-408). Moreover, the male/female difference was replicated across samples of Asians, Whites, and Blacks, as well as across samples of officers and enlisted personnel. The sex difference of 110 cm3 found by Rushton (1992) from analysis of external head measurements is remarkably similar to the 100 grams obtained in Ankney’s (1992) analysis of brain mass (1 cm3 = 1.036 grams, Hofmann, 1991).
The brain size studies do present a paradox. Women have proportionately smaller brains than do men but, apparently, the same intelligence scores. This was recognized in stronger form over 100 years ago. Gould cites G. Hervé, a colleague of Broca’s, who wrote in 1881; "Men of the black races have a brain scarcely heavier than that of a white woman." Gould’s (1996, p. 135) response was a political one, namely "I do not regard as empty rhetoric a claim that the battles of one group are for all of us". David Ankney (1992, 1995) had a more scientific response. He suggested that the difference in brain size relates to those intellectual abilities at which men excel; that spatial and mathematical ability may require more "brain" power than do verbal abilities. Other theories are that men average slightly higher in general intelligence than do women (Lynn, 1994b); or that these particular differences in brain size have nothing to do with cognitive ability but reflect greater male muscle mass and physical co-ordination on tasks like throwing and catching.
Social Class: What Gould Doesnt Want You To Know
As mentioned earlier, Gould inexplicably deleted a table which showed that averaged head sizes increased with each of 8 steps of vocational status from Hooton (1939) that had appeared on p. 109 of his first edition. Numerous other nineteenth- and early twentieth-century data sets (Broca, 1861; Sorokin, 1927; Topinard, 1878) confirmed that people of higher status occupations averaged a larger brain or head size than did those in lower ones. For example, Galton collected head measurements and information on educational and occupational background from thousands of individuals at his laboratory in the South Kensington Natural History Museum in London. However, he had no statistical method for testing the significance of the differences in head size between various occupational groups. Nearly a century later, Galton’s data were analyzed by Johnson et al. (1985), who found that the professional and semiprofessional groups averaged significantly larger head sizes (both length and width) than did unskilled groups. The results were striking for men but less clear-cut for women. Rushton and Ankney (1996) calculated cranial capacities from Johnson et al.s (1985) summary of Galtons head-size data and found that cranial capacity increased from unskilled to professional classes from 1,324 to 1,468 cm3 in men but only from 1,256 to 1,264 cm3 in women (figures uncorrected for body size). Gould mentions none of this more recent work in his purported revision.
Natural Born Criminals: What Gould Doesnt Want You to Know
In his revised edition, Gould (pp. 151-175) continues to ridicule the ‘ape-in-some-of-us’ hypothesis proposed by Cesare Lombroso (1836-1909), the Italian physician and anthropologist who founded the discipline of criminology. Lombroso argued that many criminals were throwbacks to man’s ancestral past, ill-suited to life in civilized society, and that therefore ‘natural born criminals’ could be identified by the presence of the anatomical signs of primitiveness he termed ‘stigmata’. But, contrary to Gould, Lombroso was no monomaniac and also believed that criminal behavior could arise in ‘normal’ men.
Lombroso carried out several anthropometric surveys of the heads and bodies of criminals and noncriminals, including a sample of 383 crania from dead convicts. He claimed that, as a group, criminals evidenced many features he considered primitive, including smaller brains, thicker skulls, simpler cranial sutures, larger jaws, preeminence of the face over the cranium, a low and narrow forehead, long arms, and large ears. Lombroso also examined African tribes in the Upper Nile region finding so many of these allegedly primitive traits that he concluded criminality would be considered normal behavior among them.
While Gould delights in lampooning such early evolutionary thinking, he fails to tell his readers that though Lombrosos description of the individual trees was distorted by the prejudicial lens of his time, he correctly saw the forest. Lombroso was the first to understand how Darwin’s theory of evolution provides a biological understanding for why some people are more prone to criminality than are others, how certain physical indicators allow us to predict criminality, and to recognize the critical role of the forebrain in inhibiting violent and antisocial behavior.
The reader of The Mismeasure of Man will search in vain for even a dismissing reference to any of the following recent studies of the biological correlates of criminal behavior. Raine (1993) reviewed several studies that used the state-of-the-art techniques of Computerized Tomography (CT), Magnetic Resonance Imaging (MRI), and Positron Emission Tomography (PET) to study the brains of violent and sexual offenders. He tentatively concluded that frontal lobe dysfunction was associated with violent behavior including rape. Moreover, given the relation between brain size and IQ (Rushton & Ankney, 1996; see above), Lombroso’s finding of a smaller brain in criminals relative to non-criminals is likely correct. Numerous American studies from those of H. H. Goddard in 1917 to the present, including The Bell Curve’s 12 year longitudinal study of over 12,000 youth (Herrnstein & Murray, 1994), have established the predictive relationship between IQ and crime.
Nor does Gould feel compelled to let his readers know that Lombroso’s ideas have received considerable support from recent work in behavioral genetics, a science that barely existed when Lombroso conducted his pioneering work. The same 1993 review by Raine (neither cited nor mentioned by Gould) describes 10 twin studies of adult crime based on official convictions. These studies yielded 13 analyses that together gave a concordance rate for criminal behavior of 52% for 202 monozygotic twins and only 21% for 345 dizygotic twins.
American, Danish, and Swedish studies of children who were adopted in infancy provide a means of testing the genetic theory of criminal behavior against the environmental theory. These studies support the findings of the twin studies and Lombroso’s theory of ‘natural born criminals’. Adopted children were at greater risk for criminal convictions if their biological parents had been convicted of a crime than if their adoptive parents had been. In a Danish study of some 14,000 adoptees, boys who had neither adoptive nor biological criminal parents, themselves had a 14% rate of criminal conviction. If the adoptive, but not biological parents were criminals, boys still had a conviction rate of only 15%. But if the biological but not adoptive parents were criminal, the rate increased to 20%. And, if both biological and adoptive parents were criminal, the rate increased to 25% (Mednick et al., 1984).
Studies that use self-reports of criminal behavior tell the same story as do studies of official arrest records. In one massive study, Rowe (1986) sampled almost all the eighth to twelfth graders in the Ohio Public Schools and found that MZ twins were roughly twice as alike in their self-report delinquency as were DZ twins, yielding a heritability of about 50%. Another recent study (Rushton, 1996) of 274 adult twin pairs used retrospective self-reports about destroying property, fighting, carrying and using a weapon, and struggling with the police and found a 50% heritability for such violent behaviors. Questionnaire studies of related traits such as altruism, aggression, and empathy in adults also typically show a 50% heritability (Rushton et al. 1986). Within the same family (that is, where socioeconomic status is identical), studies show it is the less intelligent and the more aggressive siblings who are more prone to delinquency.
Nor is Lombroso’s concept of stigmata as far out as Gould would have you believe. In fact, the theory of bodily markers of abnormal behavior is making a comeback, albeit from an environmentalist as well as a genetic perspective. During gestation, an insult to the fetus (such as a drug in the mothers body) that disturbs brain development, may simultaneously produce a minor physical anomaly (termed an MPA) on the external body surface. For example, during the course of pregnancy, the ears start low on the neck of the fetus and gradually drift into their standard positions. An insult to development can prematurely stop this upward migration of the ears and result in low-set ears — an observable MPA. Thus, the number of MPAs serves as a rough index of (perhaps hidden) central nervous system anomalies. For children raised in unstable families, Raine (1993) found that the number of MPAs at age 12 year was related to violent behaviors at age 21. More generally, Raines review found that antisocial children often appear markedly less attractive than normal children. In one sample of over 11,000 criminals and 7,000 controls, 60% of criminals but only 20% of controls had facial deformities, as judged by expert plastic surgeons.
Finally, consider the striking racial differences in criminal behavior. These differences are consistent across time, national boundaries, and political-economic system, which argues strongly for their having some genetic component. For example, as far back as records go, in the U.S., Orientals have been underrepresented and Blacks overrepresented in crime statistics relative to Whites. This pattern is not specific to the U.S. but is repeated around the world. Analyses of INTERPOL Yearbooks throughout the 1980s show that African and Caribbean countries have double the rate for violent crime of European countries and three times the rate of the countries in the Pacific Rim. The combined figures for murder, rape, and serious assault per 100,000 population for 1984 and 1986 were Africans — 142, Europeans — 74, and Asians — 43. For 1989-90, the pattern was unchanged: Africans — 240, Europeans — 75, and Asians — 32 (Rushton, 1990, 1995a).
It is unfortunate that Gould does not even cite, let alone attempt to refute any of these studies. Even if all of them are in some way biased and all my reasoning flawed, Gould owes it to those who rely upon his work to explain how this is so. More unfortunate is that by dismissing out of hand the hypothesis of the inclination to criminal behavior by some sneering remarks on the early work of the long-dead Lombroso and ignoring the latest research, Gould is actively obstructing scientists from finding the biogenetic treatments and environmental intervention strategies that could spare both future victims and delinquents (who, in their own way, are victims of their genes and their environments). It is thus Gould who is — in Lombosos words — the delinquent man.
Between-Group Heritabilities: What Gould Doesnt Want You to Know
Gould ( 1996, pp. 186-187, 369-370) continues to disparage the possibility of generalizing within-group findings to the causes of between-group differences. When environmentalists use nutrition as an explanation of both within-group and between-group differences this is (sensibly) not disputed. But when the exact same inference is made for heritabilities to explain both within-group and between-group differences, Gould argues it is inappropriate. But, if poor nutrition is shown to have an effect ‘within’ Whites and Blacks, it is sensible to suppose that nutrition has an effect on differences ‘between’ Whites and Blacks. If so for environmental generalization, why not for genetic generalization?
What Gould especially fails to mention is the striking and critically important finding that ‘genetic weights on IQ subtests predict racial differences’. Although the White/Black IQ gap averages 15 points, the difference ‘is more pronounced on subtests that are highly heritable within races than it is on less heritable tests’ (Jensen, 1985, Rushton, 1989b). This observation is important because it provides a test of differential predictions. Environmental theory predicts that racial differences will be greater on more culturally or environmentally influenced tests whereas genetic theory predicts they will be greater on more heritable tests. Because higher heritabilities are stronger indicators of underlying genetic substrates than are lower heritabilities, the data support the genetic hypothesis, not Gould.
It is in fact an important ’empirical’ question whether heritabilities for Blacks are the same as, or different from, those for Whites. Reason alone tells us that as environments become more benign and more equal, genetic sources of variation will become larger. For example, over the last 50 years, as environmental barriers to health and educational attainment have fallen, the variance in health and educational attainment accounted for by genetic factors has increased (Scriver, 1984; Heath et al., 1985). In animal studies, low heritabilities for body size variables are typically interpreted as showing the suppressant effect of the environment on natural growth (e.g. Larsson, 1993). The relevant question thus becomes: ‘Are IQ heritabilities for Blacks lower than those for Whites?’ Most of the evidence favors the view of equal heritabilities across the three major races. There is, however, some evidence of lower heritabilities in Blacks which would support the hypothesis of a more damaging environment. For example, Rushton and Osborne (1995) studied cranial capacity in several hundred Black and White twins and found a range of higher heritabilities (depending on corrections for age and body size) for Whites than for Blacks (47% to 56% vs 12% to 31%). The differences, however, were not statistically significant. These are, however, precisely the kinds of analyses Gould should be conducting if he wants to make a scientific, rather than a political argument about heritability!
Most transracial adoption studies also provide evidence for the heritability of racial differences in IQ. Studies of Korean and Vietnamese children adopted into White American and white Belgian homes have been conducted (Clark & Hanisee, 1982; Frydman & Lynn, 1989; Winick et al., 1975). As babies, many adoptees had been hospitalized for malnutrition. Nontheless, they went on to develop IQs 10 or more points higher than their adoptive national norms. By contrast, Black and Mixed-Race (Black/White) children adopted into White middle class families typically perform at a lower level than similarly adopted White children. For example, in the well known Minnesota Adoption Study, by age 17, adopted children with two White biological parents had an average IQ of 106, adopted children with one White and one Black biological parent had an average IQ of 99 and adopted children with two Black biological parents had an average IQ of 89 (Weinberg, Scarr & Waldman, 1992).
The only adoption studies Gould refers to (p. 370) are those showing IQ gains of very young Black children adopted into affluent and intellectual homes (presumably based on an earlier account of the Minnesota study when the children were only 7 years old) and a study of prepubertal mixed-race German children fathered by Black soldiers compared with those fathered by White soldiers which found ‘no difference’. But these apparent exceptions may ‘prove the rule’. In general, behavior genetic studies show that as people age, trait heritability increases while environmentality decreases. Differences not apparent before puberty often emerge by age 17.
Evolutionary Selection: What Gould Doesnt Want You To Know
Given that Gould doesnt believe that either brain size or intelligence differ by race and sex it is not surprising that he offers no evolutionary explanations for the origins of these differences. Gould (p. 399) acknowledges the accumulating evidence in favor of the ‘Out of Africa’ model of human origins. It holds that Homo sapiens arose in Africa 200,000 years ago, exited Africa with an African/non-African split about 110,000 years ago, and migrated east with a European/East Asian split about 40,000 years ago (Stringer & Andrews, 1988). But, Gould refuses to acknowledge any relationship between this evolutionary sequence and the parallel rankings of major racial groups in behavioral traits. Nor does he tell his readers that evolutionary selection pressures were different in the hot savanna where Africans evolved than in the cold Arctic where East Asians evolved.
Rushton (1995b) and others have proposed that the farther north the populations migrated, out of Africa, the more they encountered the cognitively demanding problems of gathering and storing food, gaining shelter, making clothes, and raising children during prolonged winters. Consequently, as the original African populations evolved into present-day Europeans and East Asians, they did so by moving in the direction of larger brains and greater intelligence, but also towards slower rates of maturation, lower levels of sex hormone, and concomitant reductions in sexual potency and aggressiveness, and increases in family stability and social conformity.
Such an evolutionary scenario fits the data from Rushtons (1995b) review of the international literature on race differences which found that on more than 60 variables Orientals and Africans consistently averaged at opposite ends of a continuum with Europeans averaging intermediately. For example, the rate of dizygotic twinning based on a double ovulation is less than 4 per 1,000 births among East Asians, 8 among Europeans, and 16 or greater among Africans. Multiple birthing is known to be heritable through the race of the mother. No known environmental factor can explain why Africans average the smallest brains and the highest twinning rates, East Asians average the largest brains and the lowest twinning rates, and Europeans average intermediately in both. Clearly, there is a need for a genetic-evolutionary explanation.
In fact, Vincent Sarich, who helped initiate the research program on biochemical taxonomy from which the ‘Out of Africa’ model developed (Sarich & Wilson, 1967), argues that Gould got his evolutionary ideas about race completely upside down. As Sarich (1995, p.86) pointed out, "it is the Out of Africa model, not that of regional continuity, which makes racial differences more functionally significant. It does so because the amount of time involved in the raciation process is much smaller, while, obviously, the degree of racial differentiation is the same — large. The shorter the period of time required to produce a given amount of morphological difference, the more selectively important the differences become." Sarich (1982, 1995) has labelled the argument that natural selection would result in geographically separated populations evolving the exact same brain size ‘behavioral creationism’. Although Gould is comfortable talking about the evolution of different body types in humans, he often writes as though he believes that societies, cultures, and mental differences spring into being full-blown, as if from the brow of Zeus or the hand of God.
With respect to the evolution of sex differences in brain size, Ankney (1992, 1995) hypothesized that differing roles of men and women during human evolution produced a sexual divergence in brain size and in abilities. Men roamed from the home base to hunt, which would select for targeting ability and navigational skills; women were relatively sedentary. Such additional abilities would have selected for relatively larger brains in men as it may require more brain tissue to process spatial information. Lynn (1994b) has also proposed that men evolved larger (more costly) brains because they enhance their probability of becoming socially dominant and thus more reproductively successful; female reproductive success is much less dependent on social status.
Conclusion: Case Closed
Others have speculated on the extent to which Gould’s political outlook has colored his scientific work (Davis, 1986; Dennett, 1995, Ruse, 1993). In Darwins Dangerous Idea, Dennett (1995) brilliantly documents how Gould has been systematically misleading his readers for decades, attempting to smuggle anti-Darwinian mechanisms into evolutionary theory with a lot of clever talk of "spandrels" "punctuated equilibrium", and "dialectical processes". Gould notwithstanding, Darwinian adaptation is the way evolution works and the mechanism on which working evolutionary scientists base their research programs.
Gould himself tells us (1996, p. 19) that he originally considered titling his book Great Is Our Sin from Charles Darwin’s remark: "If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin." Gould avers that the scientific study of human differences in mental ability is nothing but an apology for elitist European enslavement and oppression of the rest of the world — so it was in the beginning, is now, and ever shall be, world without end, amen. This has become the Apostle’s Creed of the Adversary Culture. (Do not blame criminals from poor backgrounds, they are but helpless victims of a wicked system; affirmative action and multiculturalism must be invoked to exorcise the demons of capitalist oppression, racism, and sexism). In Goulds (1996) benediction, he keeps the faith of "political correctness", while grudgingly confessing that many see it as "leftist fascism" (his words, p. 424).
In his preface, Gould describes his background and how it has affected his work. All his grandparents were Eastern European Jews whose entry into America, he believes, Goddard "would have so severely restricted" (p. 38). Thus the book is dedicated to "Grammy and Papa Joe, who came, struggled, and prospered, Mr. Goddard notwithstanding". Gould’s father fought for the leftist International Brigade in the Spanish Civil War (p. 39). He himself actively campaigned against racial oppression in the U.S.A. and in England (p. 38). I for one admire Gould for having the candor to divulge this background. No doubt personal experience affects all scholarship (including mine). However, even the most deeply held values cannot justify witholding evidence, engaging in character assassination, and repeating unfounded charges despite published refutations.
No doubt we are all prisoners of our background as well as slaves to our genes, but facts remain facts. Brain size and IQ are correlated. Men do average larger and heavier brains than do women. Asians and Europeans do average larger and heavier brains than do Africans. Higher SES groups do average larger and heavier brains than do lower SES groups.
Perhaps more than any scientist in recent memory, Gould has wielded his influence not only as a professor of science at Harvard but also through the pages of the New York Review of Books and through broadcasts on educational television, to seriously and intentionally misrepresent the science and politics of IQ. By his own standard, Gould has consigned himself to the innermost circle of hell. But science, fortunately, is not religion or politics. Gould need only own up to the facts and end his career of relentless special pleading. The second edition of The Mismeasure of Man does not measure up to Goulds own standard of "honest assesment and best judgment of evidence for empirical truth".
J. PHILIPPE RUSHTON
Department of Psychology
University of Western Ontario
London, Ontario, Canada N6A 5C2
May 16, 2008 at 12:14 am #84127
Andreasen, N. C., Flaum, M., Swayze II, V., OLeary, D. S., Alliger, R., Cohen, G., Ehrhardt, J. & Yuh, W. T. C. (1993). Intelligence and brain structure in normal individuals. American Journal of Psychiatry, 150, 130-134.
Ankney, C. D. (1992). Sex differences in relative brain size: The mismeasure of woman, too? Intelligence, 16, 329-336.
Ankney, C. D. (1995). Sex differences in brain size and mental abilities: Comments on R. Lynn and D. Kimura. Personality and Individual Differences, 18, 423-424.
Beals, K. L., Smith, C. L. & Dodd, S. M. (1984). Brain size, cranial morphology, climate, and time machines. Current Anthropology, 25, 301-330.
Bean, R. B. (1906). Some racial peculiarities of the Negro brain. American Journal of Anatomy, 5, 353-432.
Bouchard, T. J. Jr., Lykken, D. T., McGue, M., Segal, N. L., & Tellegen, A. (1990). Sources of human psychological differences: The Minnesota study of twins reared apart. Science, 250, 223-228.
Brigham, C. C. (1923). A study of American intelligence. Princeton,NJ: Princeton University Press.
Broca, P. (1861). Sur le volume et la forme du cerveau suivant les individus et suivant les races. Bulletin Socit dAnthropologie Paris, 2, 139-207, 301-321, 441-446.Brody, N. (1992). Intelligence. New York: Academic Press.
Broman, S. H., Nichols, P. L., Shaughnessy, P. & Kennedy, W. (1987). Retardation in young children. Hillsdale, NJ: Erlbaum.
Carroll, J. B. (1993). Human cognitive abilities: A survey of factor-analytic studies. New York: Cambridge University Press.
Carroll, J. B. (1995). Reflections on Stephen Jay Gould’s The Mismeasure of Man (1981): A retrospective review. Intelligence, 21, 121-134.
Clark, E. A. & Hanisee, J. (1982). Intellectual and adaptive performance of Asian children in adoptive American settings. Developmental Psychology, 18, 595-599. Davis, B. (1986). Storm over biology. Amherst, NY: Prometheus.
Degler, C. N. (1991). In search of human nature. New York. Oxford University Press.
Dennett, D. C. (1995). Darwin’s dangerous idea: Evolution and the meaning of life. New York: Simon & Schuster.
Edwards, A. W. F. (1983, January 19). When Gould meets Galton. [Review of The mismeasure of man]. London Review of Books.
Fancher, R. E. (1987). Henry Goddard and the Kallikak family photographs: Conscious skulduggery or Whig history? American Psychologist, 42, 585-590. Fletcher, R. (1991). Science, ideology and the media. New Brunswick, NJ: Transaction.
Frydman, M. & Lynn, R. (1989). The intelligence of Korean children adopted in Belgium. Personality and Individual Differences, 10, 1323-1326.
Glenn, S. S. & Ellis, J. (1988). Do the Kallikaks look menacing or retarded? American Psychologist, 43, 742-743.
Goddard, H. H. (1912). The Kallikak family: A study of the heredity of feeble-mindedness. New York: Macmillan.
Goddard, H. H. (1917). Mental tests and the immigrant. Journal of Delinquency, 2, 243-277.
Gould, S. J. (1981). The mismeasure of man. New York: Norton.
Harvey, I., Persaud, R., Ron, M. A., Baker, G. & Murray, R. M. (1994). Volumetric MRI measurements in bipolars compared with schizophrenics and healthy controls. Psychological Medicine, 24, 689-699.
Haug, H. (1987). Brain sizes, surfaces, and neuronal sizes of the cortex cerebri: A stereological investigation of man and his variability and a comparison with some species of mammals (primates, whales, marsupials, insectivores, and one elephant). American Journal of Anatomy, 180, 126-142.
Hearnshaw, L. S. (1979). Cyril Burt: Psychologist. New York: Random House. Heath, A. C., Berg, K., Eaves, L. J., Solaas, M. H., Corey, L. A., Sundet, J., Magnus, P. & Nance, W. E. (1985). Education policy and the heritability of educational attainment. Nature, 314, 734-736.
Herrnstein, R. J., & Murray, C. (1994). The Bell Curve. New York: Free Press.
Ho, K. C., Roessmann, U., Straumfjord, J. V., & Monroe, G. (1980a). Analysis of brain weight: I & II. Archives of Pathology and Laboratory Medicine, 104, 635-645.
Hofman, M. A. (1991). The fractal geometry of convoluted brains. Journal fur Hirnforschung, 32, 103-111.
Hooton, E. A. (1939). The American criminal (Vol. 1). Cambridge, MA: Harvard University Press.
Jensen, A. R. (1980). Bias in mental testing. New York: Free Press.
Jensen, A. R. (1982). The debunking of scientific fossils and straw persons. [Review of The mismeasure of man.] Contemporary Education Review, 1, 121-135.
Jensen, A. R. (1985). The nature of the black-white difference on various psychometric tests: Spearmans hypothesis. Behavioral and Brain Sciences, 8, 193-263.
Jensen, A. R. (1992). Scientific fraud or false accusations? The case of Cyril Burt. In D. J. Miller & M. Hersen (Eds.), Research fraud in the behavioral and biomedical sciences. New York: Wiley.
Jensen, A. R. (1993). Spearmans hypothesis tested with chronometric information processing tasks. Intelligence, 17, 47-77.
Jensen, A. R. (1994). Psychometric g related to differences in head size. Personality and Individual Differences, 17, 597-606.
Jensen, A. R. & Weng, L-J. (1994). What is a good g? Intelligence, 18, 231-258.
Johnson, R. C., McClearn, G. E., Yuen, S., Nagoshi, C. T., Ahern, F. M. & Cole, R. E. (1985). Galtons data a century later. American Psychologist, 40, 875-892.
Joynson, R. B. (1989). The Burt affair. London: Routledge.
Kamin, L. J. (1974). The science and politics of IQ. Hillsdale, NJ: Erlbaum.
Kandel, E. R. (1991). Nerve cells and behavior. In E. R. Kandel, J. H. Schwartz, and T. M. Jessell (Eds.), Principles of neural selection (3rd ed.) New York: Elsevier.
Larsson, K. (1993). Inheritance of body size in the Barnacle Goose under different environmental conditions. Journal of Evolutionary Biology, 6, 195-208.
Lynn, R. (1991). Race differences in intelligence: A global perspective. Mankind Quarterly, 31, 255-296.
Lynn, R. (1994a). The intelligence of Ethiopian immigrant and Israeli adolescents. International Journal of Psychology, 29, 55-56. Lynn, R. (1994b). Sex differences in intelligence and brain size: A paradox resolved. Personality and Individual Differences, 17, 257-271.
Lynn, R. (1996). Racial and ethnic differences in intelligence in the United States on the Differential Ability Scale. Personality and Individual Differences, 20, 271-273.
Mall, F. P. (1909). On several anatomical characters of the human brain, said to vary according to race and sex, with especial reference to the weight of the frontal lobe. American Journal of Anatomy, 9, 1-32.
Mednick, S. A., Gabrielli, W. F. & Hutchings, B. (1984). Genetic influences in criminal convictions: Evidence from an adoption cohort. Science, 224, 891-894.
Michael, J. S. (1988). A new look at Morton’s craniological research. Current Anthropology, 29, 349-354.
Murray, C. (1995, August). IQ, race, and heredity. Commentary, 100, (2), 20-25.
Murray, C. (1996). Afterword. In R. J. Herrnstein & C. Murray The bell curve (Softcover Edition). New York: Free Press.
Owen, K. (1992). The suitability of Raven’s Standard Progressive Matrices for various groups in South Africa. Personality and Individual Differences, 13, 149-159.
Pedersen, N. L., Plomin, R., Nesselroade, J. R. & McClearn, G. D. (1992). A quantitative genetic analysis of cognitive abilities during the second half of the life span. Psychological Science, 3, 346-353.
Raine, A. (1993). The psychopathology of crime: Criminal behavior as a clinical disorder. San Diego,CA.: Academic Press.
Rowe, D. C. (1986). Genetic and environmental components of antisocial behavior: A study of 265 twin pairs. Criminology, 24, 513-532.
Ruse, M. (1993). The Darwinian paradigm. London: Routledge.
Rushton, J. P. (1989a). The evolution of racial differences: A response to M. Lynn. Journal of Research in Personality, 23, 7-20.
Rushton, J. P. (1989b). Japanese inbreeding depression scores: Predictors of cognitive differences between blacks and whites. Intelligence, 13, 43-51
Rushton, J. P. (1990). Race and crime: A Reply to Roberts and Gabor. Canadian Journal of Criminology, 32, 315-334.
Rushton, J. P. (1992). Cranial capacity related to sex, rank, and race in a stratified random sample of 6,325 U.S. military personnel. Intelligence, 16, 401-413.
Rushton, J. P. (1994). Sex and race differences in cranial capacity from International Labour Office data. Intelligence, 19, 281-294.
Rushton, J. P. (1995a). Race and crime: International data for 1989-90. Psychological Reports, 76, 307-312.
Rushton, J. P. (1995b). Race, evolution, and behavior: A life history perspective. New Brunswick, NJ: Transaction.
Rushton, J. P. (1996). Self-report delinquency and violence in adult twins. Psychiatric Genetics, 6, 87-89.
Rushton, J. P. & Ankney, C. D. (1996). Brain size and cognitive ability: Correlations with age, sex, social class, and race. Psychonomic Bulletin and Review, 3, 21-36.
Rushton, J. P., Fulker, D. W., Neale, M. C., Nias, D. K. B. & Eysenck, H. J. (1986). Altruism and aggression: The heritability of individual differences. Journal of Personality and Social Psychology, 50, 1192-1198.
Rushton, J. P. & Osborne, R. T. (1995). Genetic and environmental contributions to cranial capacity estimated in Black and White adolescents. Intelligence, 20, 1-13.
Samelson, F. (1975). On the science and politics of the IQ. Social Research, 42, 217-231.
Samelson, F. (1982). H. H. Goddard and the immigrants. American Psychologist, 37, 1291-1292.
Sarich, V. M. (1982, October). My adventures among the creationists. Seminar presentation to Department of Anthropology, University of California, Berkeley, California.
Sarich, V. M. (1995). In defense of The Bell Curve. Skeptic, 3(3), 84-93.
Sarich, V. M. & Wilson, A. C. (1967). Immunological time scale for human evolution. Science, 158, 1200-1204.
Scriver, C. R. (1984). An evolutionary view of disease in man. Proceedings of the Royal Society of London, B220, 273-298.
Seligman, D. (1989). A question of intelligence. New York, NY: Birch Lane.
Snyderman, M. & Herrnstein, R. J. (1983). Intelligence tests and the immigration act of 1924. American Psychologist, 38, 986-995.
Sorokin, P. (1927). Social mobility. New York: Harper.
Stringer, C. B. & Andrews, P. (1988). Genetic and fossil evidence for the origin of modern humans. Science, 239, 1263-1268.
Topinard, P. (1878). Anthropology. London: Chapman and Hall.
Van Valen, L. (1974). Brain size and intelligence in man. American Journal of Physical Anthropology, 40, 417-424.
Weinberg, R. A., Scarr, S., & Waldman, I. D. (1992). The Minnesota Transracial Adoption Study: A follow-up of IQ test performance at adolescence. Intelligence, 16, 117-135.
Wickett, J. C., Vernon, P. A. & Lee, D. H. (1996). General intelligence and brain volume in a sample of healthy adult male siblings. International Journal of Psychology, 31, 238-239. (Abstract).
Willerman, L., Schultz, R., Rutledge, J. N. & Bigler, E. D. (1991). In vivo brain size and intelligence. Intelligence, 15, 223-228.
Winick, M., Meyer, K. K. & Harris, R. C. (1975). Malnutrition and environmental enrichment by early adoption. Science, 190, 1173-1175.
Yerkes, R. M. (1921). (Ed.), Psychological examining in the United States Army. Washington, DC: National Academy of Sciences.
Zindi, F. (1994). Differences in psychometric performance. The Psychologist, 7, 549-552.
TABLE 1S. J. Goulds Corrected Final Tabulation of Morton’s assessment of racial differences in cranial capacity
May 16, 2008 at 12:17 am #84128
In the following review, we conclude that a gradient
exists in brain size from East Asians to Europeans to
Africans. As such, we disagree with the prevailing view
that the racial differences in brain size established in the
nineteenth century disappear when corrections are made
for body size and other variables such as "bias." Because
of inelegancies in many of the studies, however, only tentative
conclusions are warranted, pending more definitive
research. Among the problems we encountered in
conducting our review were the following: (1) What
groups should be included in a racial category? (2) How
should we interpret group differences uncorrected for
body size? and (3) How should we interpret differences
in magnitude of only 1% to 3% between races? We decided
to (1) focus primarily on East Asians, Europeans,
and Africans, so we excluded Amerindians, Australian
Aboriginees, and East Indians; (2) correct for body size
whenever possible, as we did earlier in the section on sex
differences; and (3) assume that because a 1% difference
of 14 cm3 in brain size translates into millions of neurons
and hundreds of millions of synapses (Haug, 1987), they
are not as "miniscule" as they might appear.
In an analysis highly critical of the early literature on
wet brain mass measured at autopsy, Tobias (1970) held
that all interracial comparisons were "invalid," "misleading,"
and "meaningless" because 14 crucial variables
had been left uncontrolled. In one study or another,
these included "sex, body size, age of death, nutritional
state in early life, source of the sample, occupational
group, cause of death, lapse of time after death, temperature
after death, anatomical level of severance, presence
or absence of cerebrospinal fluid, of meninges, and
of blood vessels" (p. 3). Tobias pointed out that each of.
these variables alone could increase or decrease brain
mass by 10% to 20%, an amount equivalent to or greater
than any purported race differences. He also opposed
conclusions of race differences in structural variables
such as cortical thickness, size of frontal lobe, or complexity
of the brain’s convolutions.
Rushton (1988a), however, countered that aggregating
across studies typically cancels measurement error, at least
nonsystematic measurement error. Calculating the midpoints
of the range of scores provided by Tobias (1970,
p. 6, Table 2), he found that a "Mongoloid Series" (Tobias’s
term) averaged 1,368 g, Caucasoids 1,378 g, and
Negroids, 1,316 g. Rushton (1988b) also averaged a related
measure that took body size into account, that is,
the "millions of excess nerve cells" estimated by Tobias for
eight subgroups and nationalities (1970, p. 9, Table 3).
These were the number of neurons available for general
adaptive purposes over and above that necessary for
maintaining bodily functioning and were derivable from
equations based on brain-/body-weight relationships
(Jenson, 1963, 1973). Tobias was skeptical of the value
of his "exercise" and provided few details. Nonetheless,
Rushton (1988b) found, in millions of excess neurons,
Mongoloids = 8,990, Caucasoids = 8,650, and Negroids
= 8,550. As we shall show, modern studies confirm
racial differences in autopsied brain size.
Many more studies have estimated brain size from
cranial capacity for, as Baker (1974, p. 429) remarked,
"Skulls are many, freshly removed brains are few." The
cranial capacity literature, however, has also undergone
serious critiques, as in Gould’s (1978, 1981) reanalysis
of Morton’s (1849) data described in our Introduction.
Rushton (1988a) showed that Morton’s data, even as reassessed
by Gould (1978, p. 508, Table 6), indicated that
in cubic inches, Mongoloids = 85.5, Caucasoids = 84.5,
and Negroids = 83.0, which convert to 1,401, 1,385, and
1,360 cm3, respectively. Rushton (1995, p. 115, Table 6.1)
also showed that the same racial differences held after a
subsequent tabulation by Gould (1981), following an admission
by Gould (1981, p. 66) of his own "embarrassing"
error in calculating his 1978 figures. In both his
1978 and 1981 writings, Gould dismissed the differences
as "trivial." But, as noted, differences of 1 cubic inch
(16 cm3 ) in brain size are not trivial in that they contain
literally millions of neurons and hundreds of millions of
BRAIN SIZE AND COGNITIVE ABILITY 29
Modern studies have confirmed earlier findings. Analyzing
data on brain mass at autopsy for 1,261 American
subjects aged 25 to 80, after excluding obviously
damaged brains, Ho et al. (1980a) reported that brain
mass averaged 1,392 g in 416 White men (SD = 130)
and 1,286 g in 228 Black men (SD = 138), a difference
of 106 g. Similarly, brain mass averaged 1,252 g in 395
White women (SD = 125) and 1,158 g in 222 Black
women (SD = 119), a difference of 94 g. Although Ho
et al. (1980a) did not provide values corrected for age or
body size, the race differences in absolute brain mass
cannot be explained by those variables: Black men and
women in the sample were, on average, virtually identical
in age and size to their White counterparts.
Analyzing the world database of about 20,000 skulls,
uncorrected for body size, Beals, Smith, and Dodd (1984,
p. 307, Table 5) found that the size of sex-combined
brain cases differed by continental area. Excluding Caucasoid
areas of Asia (e.g., India) and Africa (e.g., Egypt),
19 Asian populations averaged 1,415 cm3 (SD = 51), 10
European groups averaged 1,362 cm 3 (SD = 35), and 9
African groups averaged 1,268 cm3 (SD = 85). Using
MRI to measure brain volume in a combined sample of
108 normal and clinical subjects in Britain aged 18 to 48
years, Harvey et al. (1994) found that 41 non-Caucasians
(Africans and West Indians) had a smaller brain volume
(p = .007) than did 67 Caucasians, although Harvey
et al. (1994) provided little information on ethnicity and
no details on how, or if, the samples were matched for
age, sex, or body size.
Several studies of cranial capacity .calculated from external
head measurements were conducted by Rushton,
who found, after corrections were made for body size,
that East Asians consistently averaged larger crania than
did Europeans or Africans. For example, Rushton (1992a)
examined a stratified random sample of 6,325 U.S.
Army personnel and calculated that for Asians, Whites,
and Blacks, cranial capacities corrected for body size averaged
1,416, 1,380, and 1,359 cm3, respectively (Figure
4). In an examination of averaged measurements
from tens of thousands of men and women, aged 25 to
45, collated by the International Labour Office in Geneva,
Rushton (1994) calculated that East Asians, Europeans,
and Africans averaged body-size corrected cranial
capacities of 1,308 (SD = 37), 1,297 (SD = 38),
and 1,241 cm3 (SD = 38), respectively. .
No exact solution is possible, of course, to the problem
of how large the racial differences are in brain size.
There is much variability from sample to sample, with a
clear overlap of distributions. Nonetheless, the consistency
of results found even with the use of different procedures
is noteworthy. Rushton (1995) reviewed the
world database from (1) autopsies, (2) endocranial volume,
(3) cranial capacities estimated from head measurements,
and (4) cranial capacities estimated from
head measurements and also corrected for body size, and
found, respectively, in cm 3 or equivalents: East Asians and
their descendants = 1,351, 1,415, 1,335, 1,356 (mean =
1,364); Europeans and their descendants = 1,356, 1,362,
1,341, 1,329 (mean = 1,347); and Africans and their descendants
= 1,223, 1,268, 1,284, 1,294 (mean = 1,267).
The overall mean Asian/European difference favoring
Asians was 17 cm3 , and the overall mean European/
African difference favoring Europeans was 80 cm3.
Within-race differences, due to method of estimation, averaged
Racial differences in head size appear early in life. As
shown in Table 1, head circumference of White children
(uncorrected for body size) is greater than that of Black
children in each age category by a mean of 0.36 cm or
approximately 0.2 SD. The greater head size of White
children, however, is not a function of greater body size
because Black children are taller than White children at
both 4 and 7 years (Broman et al., 1987, Tables 7-8, 8-
19). From 7 to 17 years, the White advantage in cranial
capacity is 16 cm3 (Lynn, 1993a; Rushton & Osborne,
1995). With these adolescent data, however, there is a
striking race x sex interaction, with the White/Black
difference present only for males. On the basis of the age
x sex x race data, Rushton and Osborne (1995) suggested
this was due to maturational differences, with girls maturing
earlier than boys and Blacks maturing earlier than
Whites, resulting in young Black girls being especially
larger in body size relative to their counterparts.
Because this section may be contentious for some
readers, it is worth detailing the concerns of one reviewer
who found it "very misleading." He separated and reexamined
published data and concluded that race differences
in brain size were very small. For example, he
noted that cranial capacities of Blacks in the U.S. Army
sampled by Rushton (1992a) fell within the range of Europeans
from the International Labour Office sampled
by Rushton (1994), and he noted that the U.S. Asian/
White difference showed a race X sex interaction such
that a larger difference existed for Asian women relative
to European women than for Asian men relative to European
men. (In Figure 4, for example, Asian men average
smaller brains than White men until body size corrections
are made.) The reviewer also re-examined the
International Labour Office data presented by Rushton
(1994). He/she added to the analyses samples from
North and South India that had been explicitly excluded
by Rushton (1994, pp. 288-289, along with Latin American,
North African, and Southeast Asian samples, so as
to produce the "clearest" test of the racial gradient) and
thereby reduced the White/Black difference to nonsignificance.
We do not doubt that sampling problems occur due to
differences in locating populations, measuring heads, calculating
cranial capacities, and controlling for body size.
Mean differences within races and overlap among races
are to be expected. For example, Rushton (1992a) showed
that, in the U.S. Army data, Black officers averaged significantly
larger crania than Black enlisted personnel
(1,369 vs. 1,355 cm 3 ) and (nonsignificantly) larger crania
than White enlisted personnel (1,369 vs. 1,366 cm3).
Almost any confirmed hypothesis can be made null if
one selects subsets of data. We do not believe such an ap30
RUSHTON AND ANKNEY
proach is useful for making progress in science. Identifying
potential problems in particular studies should lead
to calls for additional research, not trenchant acceptance
of the null hypothesis. As we have reviewed, deconstructing
data has led to the erroneous dismissal of fascinating
brain–behavior relationships for six decades. We think
that the onus is on critics to gather new data, using modern
techniques, if they wish to support their null hypothesis
that Asians = Whites = Blacks.
May 16, 2008 at 3:17 pm #84140
So you have posted pages from the internet, although I am not sure if they are freely available since my university library do subscribe to this journal, but it would have been shorter to post the article pdf or a link…
This notwithstanding I cannot critisize the background of the paper, but I would like to point the fact that he author defends sir Cyril Burt who has admitted creating data does not plead for complete objectivity in the review.
As for the last post, I will just point out that the conclusion is BS, and show limited grasp of statistics. The null hypothesis does not need to be supported, it can only be proved wrong, but if your data are not significant, it implies that the null hypothesis is as good as anything until someone find a better hypothesis.
December 3, 2008 at 4:07 am #87509David GeorgeParticipant
Thank goodness there was no mention about Indians. 😆 😆
January 20, 2009 at 11:57 am #88558rabidbadgerParticipant
hi i have just stumbled accross this subject while doing some impartial research of my own.
I would just like to clarify a few points if i may
ok so we have
J. PHILIPPE RUSHTON
with totaly oposing views on this subject
bluecafe seems to slip off the topic most of the way through his post
but is saying that african origined (for lack of better word) have large barin mass and that there skulls are larger. then he goes on to explain how the The gene microcephalin (MCPH1) has a large tendancy to mutate in african population which would explain the reduced brain size(although i would like to say he use the words cranial which is the bone structure and not the actual brain)
didnt he just say that the africans (blacks) had larger brains? how does that figure? if i choped off the bottom of my legs would i still put my hight down as 6ft?
i diverge anyway
it seems that all the people that have been refferenced by blue cafe are saying that all the studies havnt been totaly equal and that the negro population hasnt been represented accuratly due to disiese mutation and poor health, in my opion an acuarte sample of the african poulation.
i have gooogled Phillip V. Tobias which seems to be blues main source and havnt been able to find any of the data from his work and the only data that has been provide in this thread has been by tjj
Table 1. S.J. Gould’s ‘ corrected’ final tabulation of Morton’s assessment of racial differences in cranial capacity
Population Cubic inches Cubic centimeters
Native Americans 86 1410
Mongolians 87 1427
Modern Caucasians 87 1427
Malays 85 1394
Ancient Caucasians 84 1378
Africans 83 1361
as as from what i have been reading through gould is about as far left as you can get so its pretty relible conversion although the original data could of been modified at the source
for me to be totaly satisfied with a conclusion to this could anyone post a link to modern data related to this or where i can find it.
im sorry this hasnt been a particculary well structured/spelt post.
and am eager for more inforamtion
March 30, 2009 at 2:10 am #89919onetimepost1234Participant
Its funny how blacks will talk about having a bigger penis and thats all cool when science shows its 1/2 inch larger on average, but the moment a study showing a 10-15 point IQ gap appears its suddenly offensive and racist. Science is science let the facts speak for themselves and quit putting lables on stuff which is just based on studies.
April 3, 2009 at 4:45 am #89996
It’s funny how someone manages to compare penises with brains.
You take a measuring tape, tell people to drop their pants and just size up their pecker. The only thing you gotta standardize is the state of the woody: limp or pointing up.
Now, with brains and IQ you have a million variables you need to standardize (like said here already a myriad times), which is practically impossible.
So whilst you can easily measure people’s penises and proudly call it a scientific study, labelling a certain race more intelligent than another solely based on some IQ scores is far from a "fact"…
April 5, 2009 at 7:34 pm #90010mithParticipant
Why does none of this data show any STDEV, how else are we supposed to see significance?
April 14, 2009 at 4:52 am #90145Bob017Participant
"This notwithstanding I cannot critisize the background of the paper, but I would like to point the fact that he author defends sir Cyril Burt who has admitted creating data does not plead for complete objectivity in the review."
Not true, Burt did not admit to creating data. Also, after he passed away one of his academic ‘rivals’ at his University had a large amount of Burt’s papers destroyed. The whole episode has been discussed in a couple of books.
More interestingly though, subsequent twin studies have reached similar findings to Burt. Behavioural traits are significantly heritable.
"Behavioral genetics has repeatedly found that the “shared environment” — everything that siblings growing up in the same home have in common, including their parents, their neighborhood, their home, their peer group and their school — has less of an influence on the way they turn out than their genes. In many studies, the shared environment has no measurable influence on the adult at all. Siblings reared together end up no more similar than siblings reared apart, and adoptive siblings reared in the same family end up not similar at all. A large chunk of the variation among people in intelligence and personality is not predictable from any obvious feature of the world of their childhood." http://www.nytimes.com/2009/01/11/magaz … wanted=all
Also, it’s worth mentioning that ‘Mismeasure of Man’ cited above is a badly flawed propaganda piece. Have a read of the various negative reviews which are linked on wikipedia.
David J. Bartholomew, from London School of Economics, who has writtena textbook on factor analysis, also explains in "Measuring Intelligence: Facts and Fallacies" where Gould goes wrong in this area.
Gould also makes some misleading comments about the early performance of Jewish migrants on psychometric tests. Goddard never found that Jews as a group did poorly, and there is no evidence the tests were used in passing the 1924 Immigration Act (see, Franz Samelson (1975, 1982), Snyderman & Herrnstein 1983).
Gould states that Morton "doctored" his collection of results on cranial size, but J. S. Michael (1988) remeasured a random sample of the Morton collection he found that very few errors had been made, and that these were not in the direction that Gould had asserted.
April 14, 2009 at 4:56 am #90146
November 4, 2009 at 1:09 am #94454bethrjacobsParticipant
You know my I.Q. was wrongly told to me. I don’t know if the person out right lied but they had two standardized test to look at with in one point of each other. Standardized public school I.Q. tests and I didn’t know for almost twenty years that my I.Q. is actually ten points and an entire percentile higher then was stated to me. I believe it made me act “slower’ all these years…
Was this person also female a bigot; a sexist? I will never know.
My mother has an I.Q. of 165 but I believe she has been so discriminated against it’s impossible for her to even get close to what one could do with this. Not my mom but to the point. And these auditions are held behind a scrim…
November 4, 2009 at 3:18 am #94473TheVirusParticipant
Brain size does not always determine IQ. Women, for example have smaller brains than men, but theirs are more developed than men’s.
November 14, 2009 at 9:09 pm #94866bethrjacobsParticipant
…very nice Virus…
April 4, 2010 at 2:01 pm #98794beachloverParticipant
Brain Size Matters: a Reply to Peters
by J. Philippe Rushton and C. Davison Ankney
University of Western Ontario
‘Rushton (1995) reviewed 100 years of scientific literature and found that across a triangulation of procedures, brains of East-Asians and their descendants average about 17 cm3 (1 in3) larger than those of Europeans and their descendents whose brains average about 80 cm3 (5 in3) larger than those of Africans and their descendents. Although critics can pick outliers to show counter-examples and suggest opposite trends (as could critics of a statement that men are, on average, taller than women) the aggregated data are clear (see Rushton, 1995, for full discussion of alleged counter examples).’
‘Globally, racial differences in brain size parallel those found in measured intelligence. Europeans in North America, Europe and Australasia have mean IQs of around 100. For East Asians, measured in North America and in Pacific Rim countries, means range from 101 to 111. Africans living south of the Sahara, African-Americans and African-Caribbeans (including those living in Britain), have mean IQs of from 70 to 90 (Lynn, 1991). Elementary speed of information processing in 9- to 12-year-olds, in which children decide which of several lights stands out from others, show that racial differences in mental ability are pervasive. All children can perform the tasks in less than 1 s, but more intelligent children, as measured by traditional IQ tests, perform the tasks faster than do less intelligent children. Japanese and Hong Kong children have faster decision times (controlling for movement time) than do British and Irish children who have faster decision time than South African Black and African-American children (Jensen, 1993; Jensen & Whang, 1993; Lynn, 1991).’
For the record, I fit firmly into the group that comes ‘second’.
April 4, 2010 at 2:07 pm #98795beachloverParticipantquote David George:
C’mon David, I’m including you in ‘east asians’ – top of the pile!
June 25, 2010 at 6:33 pm #100319
Controversial Study of African IQ Levels Is ‘Deeply Flawed’
ScienceDaily (Jan. 21, 2010) – The controversial study on African IQ levels conducted by psychologist Richard Lynn is deeply flawed. This conclusion is the outcome of studies by Jelte Wicherts, Conor Dolan, Denny Borsboom and Han van der Maas of the University of Amsterdam (UvA) and Jerry Carlson of the University of California (Riverside).
Their findings are set to be published in Intelligence, Personality and Individual Differences, and Learning and Individual Differences.
In an oft-quoted literature study conducted in 2006, Lynn concluded that black Africans have an average IQ of less than 70 (compared to an average western IQ of 100). Lynn suggested that these low IQs are indicative of a low intelligence level, claiming this offered an explanation for the low level of economic development in sub-Saharan countries.
Lynn’s study is well known among psychologists, and has been referenced by academics such as Nobel laureate James Watson, and the authors of the controversial book The Bell Curve — Intelligence and Class Structure in America (Richard Herrnstein and Charles Murray: Freepress, 1994).
African IQ scores prove flawed
Wicherts and his colleagues examined over 100 published studies, concluding that there is no evidence to back up Lynn’s claims. Amongst other flaws, Lynn used selective data by systematically ignoring Africans with high IQ scores. The researchers also claim that African IQ test scores cannot be interpreted in terms of lower intelligence levels, as these scores have different psychometric characteristics than western IQ test scores. Until now, the incomparability of Western and African IQ scores had never been systematically proven.
The scientists point out that the average African IQ is currently comparable to the average level in the Netherlands around 1950. However, IQ scores in Western countries have risen sharply over the course of the 20th century. In view of this trend, Wicherts and his colleagues claim there are no reasonable grounds to conclude that sub-Saharan countries are poor due to the lower IQ scores of their populations. As it turns out, the average IQ of African adults is seeing a similar rising trend, which is expected to continue if living conditions in Africa improve in future.
June 25, 2010 at 6:37 pm #100320
Personality and Individual Differences
Volume 48, Issue 2, January 2010, Pages 91-96
Copyright c 2009 Elsevier Ltd All rights reserved.
Why national IQs do not support evolutionary theories of intelligence
Jelte M. Wicherts, Denny Borsbooma and Conor V. Dolana
aDepartment of Psychology, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam, The Netherlands
Received 16 February 2009; revised 19 May 2009; accepted 26 May 2009. Available online 24 June 2009.
Kanazawa (2008), Templer (2008), and Templer and Arikawa (2006) claimed to have found empirical support for evolutionary theories of race differences in intelligence by correlating estimates of national IQ with indicators of reproductive strategies, temperature, and geographic distance from Africa. In this paper we criticize these studies on methodological, climatic, and historical grounds. We show that these studies assume that the Flynn Effect is either nonexistent or invariant with respect to different regions of the world, that there have been no migrations and climatic changes over the course of evolution, and that there have been no trends over the last century in indicators of reproductive strategies (e.g., declines in fertility and infant mortality). In addition, we show that national IQs are strongly confounded with the current developmental status of countries. National IQs correlate with all the variables that have been suggested to have caused the Flynn Effect in the developed world.
Keywords: Evolutionary psychology; Flynn Effect; Race differences
Find entire study here: http://wicherts.socsci.uva.nl/wicherts2010.pdf
June 25, 2010 at 6:40 pm #100321
Personality and Individual Differences
Volume 48, Issue 2, January 2010, Pages 104-106
Copyright c 2009 Elsevier Ltd All rights reserved.
Evolution, brain size, and the national IQ of peoples around 3000 years B.C
Jelte M. Wicherts a, Denny Borsboom a and Conor V. Dolan a
aUniversity of Amsterdam, Department of Psychology, Amsterdam, The Netherlands
Received 22 August 2009; accepted 26 August 2009. Available online 18 September 2009.
In this rejoinder, we respond to comments by Lynn, Rushton, and Templer on our previous paper in which we criticized the use of national IQs in studies of evolutionary theories of race differences in intelligence. We reiterate that because of the Flynn Effect and psychometric issues, national IQs cannot be taken to reflect populations’ levels of g as fixed since the last ice age. We argue that the socio-cultural achievements of peoples of Mesopotamia and Egypt in 3000 B.C. stand in stark contrast to the current low level of national IQ of peoples of Iraq and Egypt and that these ancient achievements appear to contradict evolutionary accounts of differences in national IQ. We argue that race differences in brain size, even if these were entirely of genetic origin, leave unexplained 91-95% of the black-white IQ gap. We highlight additional problems with hypotheses raised by Rushton and Templer. National IQs cannot be viewed solely in evolutionary terms but should be considered in light of global differences in socio-economic development, the causes of which are unknown.
Keywords: Evolutionary psychology; Flynn Effect; Race differences; Brain size
Find entire study here: http://wicherts.socsci.uva.nl/wichertsPAIDrejoinder.pdf
June 25, 2010 at 6:44 pm #100322
Volume 38, Issue 1, January-February 2010, Pages 1-20
Copyright c 2009 Elsevier Inc. All rights reserved.
A systematic literature review of the average IQ of sub-Saharan Africans
Jelte M. Wicherts, Conor V. Dolan a and Han L.J. van der Maas a
a Department of Psychology, Psychological Methods, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam, The Netherlands
Received 8 October 2008; revised 6 May 2009; accepted 12 May 2009. Available online 9 June 2009.
On the basis of several reviews of the literature, Lynn [Lynn, R., (2006). Race differences in intelligence: An evolutionary analysis. Augusta, GA: Washington Summit Publishers.] and Lynn and Vanhanen [Lynn, R., & Vanhanen, T., (2006). IQ and global inequality. Augusta, GA: Washington Summit Publishers.] concluded that the average IQ of the Black population of sub-Saharan Africa lies below 70. In this paper, the authors systematically review published empirical data on the performance of Africans on the following IQ tests: Draw-A-Man (DAM) test, Kaufman-Assessment Battery for Children (K-ABC), the Wechsler scales (WAIS & WISC), and several other IQ tests (but not the Raven’s tests). Inclusion and exclusion criteria are explicitly discussed. Results show that average IQ of Africans on these tests is approximately 82 when compared to UK norms. We provide estimates of the average IQ per country and estimates on the basis of alternative inclusion criteria. Our estimate of average IQ converges with the finding that national IQs of sub-Saharan African countries as predicted from several international studies of student achievement are around 82. It is suggested that this estimate should be considered in light of the Flynn Effect. It is concluded that more psychometric studies are needed to address the issue of measurement bias of western IQ tests for Africans.
Keywords: Group differences; Black-White differences; Flynn Effect; Race differences; Cross-cultural comparison; National IQ
Find entire study here: http://wicherts.socsci.uva.nl/wicherts2009.pdf
June 25, 2010 at 6:47 pm #100323
Volume 38, Issue 1, January-February 2010, Pages 30-37
Copyright c 2009 Elsevier Inc. All rights reserved.
The dangers of unsystematic selection methods and the representativeness of 46 samples of African test-takers
Jelte M. Wicherts, Conor V. Dolan a and Han L.J. van der Maas a
a University of Amsterdam, The Netherlands Received 13 October 2009; accepted 6 November 2009. Available online 3 December 2009.
In this rejoinder, we criticize Lynn and Meisenberg’s (this issue) methods to estimate the average IQ (in terms of British norms after correction of the Flynn Effect) of the Black population of sub-Saharan Africa. We argue that their review of the literature is unsystematic, as it involves the inconsistent use of rules to determine the representativeness and hence selection of samples. Employing independent raters, we determined of each sample whether it was (1) considered representative by the original authors, (2) drawn randomly, (3) based on an explicated stratification scheme, (4) composed of healthy test-takers, and (5) considered by the original authors as normal in terms of Socio-Economic Status (SES). We show that the use of these alternative inclusion criteria would not have affected our results. We found that Lynn and Meisenberg’s assessment of the samples’ representativeness is not associated with any of the objective sampling characteristics, but rather with the average IQ in the sample. This suggests that Lynn and Meisenberg excluded samples of Africans who average IQs above 75 because they deemed these samples unrepresentative on the basis of the samples’ relatively high IQs. We conclude that Lynn and Meisenberg’s unsystematic methods are questionable and their results untrustworthy.
Keywords: Systematic literature review; National IQ; Group differences in IQ
Find entire study here: http://wicherts.socsci.uva.nl/wicherts2010AFRrejoinder.pdf
June 25, 2010 at 6:49 pm #100324
Learning and Individual Differences
Article in Press, Corrected Proof – Note to users
Copyright c 2009 Elsevier Inc. All rights reserved.
Raven’s test performance of sub-Saharan Africans: Average5 performance, psychometric properties, and the Flynn Effect
Jelte M. Wicherts a, Conor V. Dolan a, Jerry S. Carlson b and Han L.J. van der Maas a
a Department of Psychology, Psychological Methods, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam, The Netherlands
b University of California, Riverside, United States
Received 19 May 2009; revised 19 November 2009; accepted 3 December 2009. Available online 16 December 2009.
This paper presents a systematic review of published data on the performance of sub-Saharan Africans on Raven’s Progressive Matrices. The specific goals were to estimate the average level of performance, to study the Flynn Effect in African samples, and to examine the psychometric meaning of Raven’s test scores as measures of general intelligence. Convergent validity of the Raven’s tests is found to be relatively poor, although reliability and predictive validity are comparable to western samples. Factor analyses indicate that the Raven’s tests are relatively weak indicators of general intelligence among Africans, and often measure additional factors, besides general intelligence. The degree to which Raven’s scores of Africans reflect levels of general intelligence is unknown. Average IQ of Africans is approximately 80 when compared to US norms. Raven’s scores among African adults have shown secular increases over the years. It is concluded that the Flynn Effect has yet to take hold in sub-Saharan Africa.
Keywords: Black-White differences; Cognitive abilities; Cross-cultural comparison; Measurement equivalence; Measurement invariance
Find entire study here: http://wicherts.socsci.uva.nl/wichertsRavenAfr2010.pdf
June 25, 2010 at 7:46 pm #100325quote Jedi of Zen:
Jedi of Zen you are incorrect. The modern day concensus is that race exists as a purely social construct, mainly due to the fact that our contemporary ideas of racial classificaton are based exclusively on 19th century folk taxonomic principles that rarely at all correspond with modern day scientific studies based on wholistic population genetics. A good example that illustrates this fact, is the fact that many populations on the African continent that are generally regarded as "black" such as Somalis, Ethiopians and Sudanic groups such as the Beja, are in fact genetically closer to Eurasian populations than they are to other black Africans. See studies:quote :
Find entire study here: http://www.nature.com/ejhg/journal/v13/n7/full/5201390a.htmlquote :
Find entire study here: http://findarticles.com/p/articles/mi_qa3659/is_200304/ai_n9235660/pg_3/
And medical practioners do not speak about "race" differences in the epidemiology of different diseases, rather they speak of population differences in the prevalence of such diseases:quote :
Find the entire study here: http://www.meddean.luc.edu/depts/prevmed/main/Publications/Papers/NEJM%20Race%20paper.pdf
July 9, 2010 at 11:07 am #100508JackBeanParticipant
You may want to read this:
Henrich J. et al.: The weirdest people in the world? Behavioral and Brain Science, doi: doi:10.1017/S0140525X0999152X
but in the meaněwhile you better stop spamming, unless you wanna be banned!
July 15, 2010 at 3:51 am #100565vsdfaParticipant
The modern day concensus is that race exists as a purely social construct, mainly due to the fact that our contemporary ideas of racial classificaton are based exclusively on 19th century folk taxonomic principles that rarely at all correspond with modern day scientific studies based on wholistic population genetics.
February 19, 2011 at 12:49 am #103551Jenab6Participantquote vsdfa:
What vsdfa said isn’t true. Races are experimentally verifiable, biological realities. They are not social constructs.
A social construct is something like "human dignity," which exists only because people agree to behave as if it did. But when faced with forces that don’t share that agreement, such as an enemy, a hungry wild animal, or an elemental force of nature, most people quickly realize that "human dignity" isn’t really a fact of nature, but is rather a human fiction, which offers no protection at all for the simple reason that it has no physical existence.
The idea that race might be a social construct began as a hypothesis introduced by Richard Lewontin, a Harvard geneticist, in 1972. He claimed that the genetic differences between races were so slight that no one working only with genetic data would categorize people as Asians, Whites, Blacks, Mestizos, etc. Lewontin said that racial classification "is now seen to be of virtually no genetic or taxonomic significance."
Leftist racial egalitarians were quick to pick up on Lewontin’s words and create a number of chants and slogans from them, including "Race is a social construct" and "There’s only One Race, the Human Race." The Lewontin Hypothesis almost immediately became a required belief among the politically correct. Unfortunately for them, less than 30 years later it became possible for geneticists and forensic scientists to conduct a statistical analysis of genetic markers in order to see whether their clusters correlated with the commonly identified racial groups.
They did. By 2005, it was well documented that Lewontin had been wrong. Practically every analysis of genetic markers demonstrated the biological reality of racial identities. In one of them, conducted by Tang, Quertermous, and Rodriguez, et. al., in 2005, all except five of 3636 test subjects (including Asians, Whites, Blacks and Mestizos) sorted statistically into the cluster of genetic markers that corresponded to their self-identified racial group. The success rate for predicting how someone would classify himself racially, using only his genes as information, was approximately 99.9 percent, according to that study.
It had long been possible for physical anthropologists to sort skeletal remains by race with very good accuracy, using only the shapes of skull, jaw, teeth and bones as guides. By the first years of the 21st century, it had become possible for forensic experts to do the same thing with DNA, which enabled more accurate identifications of fathers in paternity disputes and in showing police when they have arrested the right suspect, or, sometimes, when they’d nabbed the wrong fellow.
But leftists are even worse than sophomores when it comes to suffering correction. They have the pugnaciousness to call people who are much more informed than they are themselves, "ignorant." They’ve adopted the "social construct" slogan, and, come what may, they’re not ever going to give it up. They will simply keep on using that slogan in lieu of evidence again and again.
Anyone who has followed race-related discussions for long has noticed a peculiarity in the manner in which “racial equality” proponents argue. You can even see it here, in this discussion. They never bring forward positive evidence for racial equality. Or, at least, I haven’t seen them attempt to do so. They behave as if equality were given, already proved—by persons unknown, at a time and place unmentioned, by measurements unspecified. It’s one of those things that “everyone” is supposed to “know.” In debate, or in peer review "rejoinders," they never disclose any countervailing data. Rather, they confine themselves to picking nits in the completeness of their opponents’ information, or to claiming to find flaws in their opponents’ analyses. The rhetoric of racial equality proponents rather reminds one of Creationists, trying to cast doubt upon the theory of evolution.
As the result of the experimental falsification of the Lewontin Hypothesis, hence the verification of race in humans as a biological reality, the leftist theory of racial equality is now in the position that modern astronomy imposed upon the doctrine of the medieval Church. As the evidence for a sun-centered solar system kept mounting, those who clung to the old Earth-centered paradigm began looking sillier and sillier. Eventually—meaning after 400 years of intransigence—a Pope admitted that Galileo had been right all along and that the former Church position had been in error. That’s probably more graciousness than we’ll ever see from the dogmatic leftists on the subject of race.
Really, the idea of racial equality ought to have been suspect in any reasonable person’s mind from the beginning. Nature produced the visible racial differences, which we usually notice on inspection, and which we mostly agree are trivial. But then the leftists declared that those "cosmetic" racial differences were the only differences between the races. It would be a very strange thing indeed if nature, which created all of the heritable traits in organisms, had been aware of leftist sensibilities since the dawn of time, and had taken great care—with humans—to permit the evolution of only those racial differences having no social significance of which leftists might disapprove.
The arguments of racial separatists, persons who look askance at multiracial societies and prefer the company of their own kind, are not without merit. Rather than repeat those arguments in racial terms, allow me to make a simple analogy. Races may be compared with metal canisters filled with gas. The net effect of their collective behavior is like the temperature of the canisters. You can measure their temperatures in order to find out whether they are inside a safe-handling range. If you forgo testing the temperature, or if you are informed about the temperature but choose to disregard any "too hot to handle" warnings, then you risk being burned.
However, temperature does not predict the speed of any particular molecule in the canister. It only tells you what the average speed is. Likewise, statistics on HIV infection rates, crime rates, IQ scores, and similarly important subjects, broken down by race, might tell us that a certain race is, in general, a rather nasty bunch of savages, even though we realize that there are bound to be exceptions. The existence of those exceptions does not justify or require our making overtures to persons belonging to such a race, or going over to them and associating ourselves in such a way that we will be burned.
February 22, 2011 at 6:42 am #103587paintballParticipant
That’s a good analogy Jenab6. I’m going to start using yours, instead of the one I have been using. 😀
Add me to the group that considers it established that intelligence is genetic (polygenic trait) and average intelligence varies with race. I don’t think brain size is a very exact measure, it’s not good for much more than saying "Okay homo erectus was probably less intelligent than h. sapiens."
Some of the research coming out these days is really fascinating, just a month ago this was published
Rare copy number deletions predict individual variation in intelligence.
The sum total length of deletions is inversely related to intelligence; white/Anglo group was compared to "other" and found to be more resistant to the effect of deletions.
March 10, 2011 at 2:08 am #103844rich7292Participant
Why is it that everyone of you go all out to try to prove that there can not possibly be a difference in IQ between races? Better yet why is it that you think it is racist to think this? When I have never seen a study trying to prove that blacks are superior to all other races athletically questioned? Have you ever thought racism could come into the second hypothesis?
June 3, 2011 at 2:29 am #105145commentParticipant
It is undeniable ( no study necessary ) that if one were to draw a line from the boot of Italy to London England and take a swath 300 miles east and west you would find, over history, 95% of the geniuses of the world. Art, music, literature, mathematics, physics, inventions ; you name it. Do we need skull size measurement ? The results are what count. By the way most of the geniuses showed their talent as teenagers.
July 4, 2011 at 12:06 pm #105473supParticipantquote Jedi of Zen:
It’s not just in proportion to their body size, but also on an absolute scale. Studies show that East Asians have larger skulls and cranial capacities on average than whites, and whites larger than blacks. Other studies demonstrate the same relationship with regards to brain size and IQ scores. Studies of children adopted by parents of a different race demonstrate that the differences are mostly influenced by genetics rather than cultural norms.
However, note that IQ tests attempt to measure some form of intelligence but do not necessarily accurately measure intelligence overall. Also note that a certain high IQ score requirement is neither necessary nor sufficient to warrant the label "genius" in the most common application of the term. IQ scores, intelligence, and ingenuity are all different things. The studies I refer to simply suggest that East Asians have higher IQ scores on average than whites, and whites higher than blacks. This does not imply greater overall intelligence or a greater proclivity to ingenuity, each notion of which is currently very ambiguous and difficult to precisely characterize.
July 5, 2011 at 11:32 pm #105493MorlafParticipantquote david23:
I don’t think you are correct. "Racism" and more generally prejudices based on race have been around for as long as man has been around. But attemping to pull this topic back into the domain of Biology rather than sociology i have to say that "Prejudices" are a healthy mechanism a bit like "fear" is.
October 1, 2011 at 10:38 pm #106532quote comment:
Yet while great civilizations thrived in the more southerly regions of the world these same Western Europeans were living in caves and mud huts. The geniuses you speak of came on the scene only in the last few hundred years, and they have been decidedly few and far between. Probably for every billion Europeans produced one of them becomes Isaac Newton or similar. In other words, it’s a freak occurrence of the most extraordinary and extreme nature. In fact take away Isaac Newton and we may not even have a space program. Just one individual out of billions of Europeans. That is hardly testimony to the idea of white supremacy. Real supremacy would dictate that Newton should be the norm, rather the the most grossest of exceptions.
By the way, people are only classified as geniuses if their genius is recognized by society. Surely there were some European geniuses in earlier periods of European history, but they were not recognized as such, as the means by which such genius could find expression and be appreciated globally did not exist. You could say the same for Africa, Asia, native Ameria, etc.
If intelligence is genetic and if Europeans are most prone to intelligence, why is it we can’t go beyond a few hundred years to find examples European geniuses? Again, highly sophisticated and refined civilizations were active in other parts of the world while the same Europeans "from the boot of Italy to London England" were essentially savage barbarians.
February 15, 2012 at 3:45 pm #109651
I confess I am sick of this pseudo fraternal speech of some experts which turn science diffuse and obscure.
My wife is black and I love her, but let’s get to facts: black man is clearly stronger physically and that can be attested in several official sports results when the sport demands strength and speed: athletics, box, long jump, etc… but when the sport demands technique, then Asians and Europeans tend to have better results. That’s a fact!
Let’s cut the mazes created by some pseudo fraternal scientists and let’s get to facts.
Black Africans have a smaller brain capacity when compared to Caucasians and that has strong influences on IQ. Craniologists clearly know that for example through human evolution a very pertinent factor for attesting the level of evolution of the Homo specie was the brain capacity. How many black men have won Nobel prizes for physics, chemistry or other prizes for mathematics? I know what you’ll say, the typical stuff: cultural factors, bla…
Look, I am not at all racist, I have many black friends and my wife is black, but I confess I’m sick of these pseudo scientists with this fraternal line of thought which want to make all human beings equal like mere twins. All human beings have differences, and have similarities and black African men are statistically less intelligent than Caucasian men. But that shall never be a factor for racism, discrimination, hate or superiority. All men shall live in peace and harmony and should obviously be treated equally but let’s be objective when it concerns to these clear facts.
February 16, 2012 at 11:07 am #109671quote Seth90210:
This is the great problem of talking about these issues, because topics like supremacy and superiority come always to the subject matter, and that obviously make science diffuse due to political and social issues.
Look, for me, the point is clear: We live, on western society, based socially and culturally on the French revolution principles and on the freemasonic doctrines of Liberty, Equality and Fraternity, so, it is very unpopular and controversial when clear studies claim that men have higher IQ levels than women or that white man has higher IQ than black man, because it will be seen as a factor for discrimination or supremacy, when many other men in past made a great philanthropic effort to abolish slavery and give equal rights to women and black man.
And other factor is that nowadays people see intelligence as a prime factor for supremacy, and actually social studies show it is not. It is much more important on life, socially, for the success of an individual, qualities like dynamism, hard working, diligence and activism, than just intelligence.
I evoke Boileau:
Nothing is really beautiful but truth, and truth alone is lovely
February 16, 2012 at 11:07 am #109672
February 20, 2012 at 3:36 am #109753
Well beyond your anecdote (and remember, the plural of anecdote is not data) what do you have to prove your assertion of a correlation between IQ and skin colour?
February 20, 2012 at 10:08 am #109763quote canalon:
Well, at first glance, I don’t know if is there any correlation between skin colour and brain capacity, but empirically I would say there is, if you just compare native europeans with native africans
Though, I’ve read on an article that for example some black americans have a brain capacity similar to any other white caucasian.
So I conclude, anecdotally, that nowadays, there isn’t any correlation between IQ and skin colour…
January 12, 2013 at 9:53 pm #113371JGoodallParticipant
I was an anthropology/primate physiology major for awhile,before I ended up switching majors, as hiding out in the jungle with apes (my dream) did not generally pay well 😉
I want to be able to be honest here, even in the face of political correctness. But I remember many studies with chimpanzees, especially ones comparing them to humans in various ways.
One such study was a comparative analysis of childhood development in both apes and humans. The children involved ranged from 3 to 7.
When chimpanzees were compared to human children, both being under 6, they always surpassed the humans. Especially in spatial relations. BUT, then the chimp development just stopped. They never got past age 6. They were done. But the human children first caught up to the chimps, and then surpassed them for the next 20 years. It would seem the humans got a slower start, but then later caught up (at about 6yrs), then way surpassed.
Im not trying to be racist in any way (and it is a shame I have to even say that). But this is biology.
And lower primates seem to always be ahead at 4 yrs, but not for long.
I havent even thought of the comparative study for 25 yrs…UNTIL I read your post. Gives me something to chew on. Thx
May 23, 2013 at 11:06 am #113852
Interesting speculation with a big dose of wishful thinking. Sorry to disappoint the deluded but there’s absolutely no evidence:
A) that blacks are less intelligent than whites and Asians
B) that blacks have smaller brains than whites or Asians
In fact there are mountains of evidence to the contrary, which is why this junk will never see the light of day in mainstream science, academia or society. And it is not because of political correctness either, it’s because it’s stupid. You’re wasting your time. This idiocy will never gain currency, particularly as people of different cultures are interacting more and more. In other words, people are getting to know black people more and more. People are getting to know Africans more on more. And that’s ultimately why bigots who preach this junk have a very, very hard sell.
To even suggest that there is a uniform group known as "blacks" whose brains can be measured is the profoundest type of stupidity. Which blacks? From which part of Africa? Somebody went around Africa measuring heads? Who? Where? Where’s the data? I’m African and I happen to know that people from my part of Africa generally have larger heads (and larger brains) than whites and Asians. We have broad features. If you were to transplant my nose and my mouth onto the average white guy’s face, half of it would be obscured.
If a real racial hierarchy in intelligence existed proponents could sit back and relax and let the evidence speak for itself. But since the evidence is non-existent they take to their keyboards, wasting hours upon hours of their time, arguing endlessly, writing copiously, trying to prove to themselves, and to others, something that would be self-evident and glaringly obvious if it were real. But it ins’t real. For every delusional bigot on this thread I can identify a black person who is smarter than him, all his friends and family and every other white person he has ever known and will ever know. Now how exactly would an intellectually inferior race produce people who are substantially more intelligent than the very bigots who are denigrating their intelligence?
This is an area where people with deep-seeded insecurities and complexes try to justify themselves to themselves. I mean, actually citing clowns like Rushton and the other rogues gallery of pseudoscientific quacks in what is supposed to be a serious debate. LOL.
May 23, 2013 at 8:50 pm #113855quote jfolpf:
You mean the same Africans who grossly outperform Europeans when operating in the same U.S. environment?
http://www.chron.com/news/article/Data- … 600808.php
http://www.realclearpolitics.com/articl … sible.html
http://applauseafrica.com/education/146 … princeton-
Let me ask you a question. Should we rely on this empirical and direct evidence or should we rely on your anecdotes and opinions? Before you answer, remember this is a science blog.
May 24, 2013 at 7:48 am #113857
^ You may wanna check your quotes, I don’t think it was Canalon who wrote what you quoted above.
May 24, 2013 at 7:50 pm #113858quote biohazard:
Yeah, after I caught that it was too late to change it. Maybe Canalon can fix it. I’d hate to give the impression that it’s his quote.
May 28, 2013 at 2:15 am #113868quote Seth90210:
I came back from my long disappearance and fixed your problems. But in that case, if you had failed to raise from the dead, any mods would have been able to solve your problem.
May 28, 2013 at 8:33 pm #113873quote canalon:
Seeing as how you’re one of the rational and reality-based people on the thread you’re the last person that statement should be attributed to. 😆
October 12, 2013 at 3:04 pm #114481DavidSimsParticipant
I’d first point out that the contention "the races are equals" [in anything] is a statement that should be supported by positive evidence. Those of us who are reading this should know that your case isn’t made simply because someone with whom you disagree has not made his. Your side of a debate isn’t privileged to be any kind of default position, standing like a castle in the air, unless someone else can prove that castles can’t stand upon air.
So the second presumption of the poster "TruthIsHoly" is his giving us the impression that the races must be equals without offering us any proof that it is so. His first presumption is his selection of a politically pushy name. Truth might be holy, but there are no holy sources of truth, including his keyboard or the studies he quotes from. All valid experiments are repeatable, truth is known only with some degree of confidence or other, and nobody ever has the "holy" final word on what the truth is.
Let us observe that it is not at all unreasonable for human intelligence to correlate well with brain size, or with the ratio of brain mass to body mass. We can more-or-less see that in human evolution, and we see it in primates other than humans, and we see it in mammals generally.
Let’s also take cognizance of the fact that brain sizes might indeed vary racially in the same way that average skin coloring and average height do.
The claim of inequality among races isn’t strange. Whether it is true or false is for an examination of relevant data to determine. But on its face it is an eminently reasonable statement.
In the United States, persons who are called "blacks" or "African-Americans" are about, on average, 25% white. That is to say, American blacks are commonly mulattoes of mixed white and black ancestry. Decades of psychometric study has provided ample information to estimate that the distribution of IQ in US-resident blacks is normal at 85±12.4, and that the distribution of IQ in US-resident whites is normal at 103±16.4.
The averages in those distributions were mentioned in "Thirty Years of Research on Race Differences in Cognitive Ability" by Rushton and Jensen, published in Psychology, Public Policy, and Law. The standard deviations were taken from a 1963 study by Kennedy, Van de Riet, and White.
It has been observed that the intelligence of mulatto persons are, in the usual run of such people, correlated positively with their percentage of white ancestry.
And so, prior to any actual inspection of Richard Lynn’s African data, his findings would seem consistent with an extrapolation toward the percentages of racial blackness that we can find in Africa.
Now, I notice that objections have been made regarding Lynn’s methodology; specifically, he’s been accused of cherry-picking. However, might I suggest that cherry-picking is something that Lynn’s critics would prefer to do? To put it plainly, I suspect that perhaps Richard Lynn refrained from doing any cherry-picking, such as would have enhanced the proportion of his test subjects who were above the average in the various African countries included in his study, however those who complain about Lynn’s findings would have done just that thing, if they had conducted a similar study. I think that Lynn took them as they came, in a true random sample, and that the findings that resulted have displeased those who think that certain of their beliefs are "holy truths."
October 15, 2013 at 4:42 pm #114595quote DavidSims:
The brain-to-body mass ratio (absolute brain size) is a useful predictor of the intelligence of a species, but you can’t just extrapolate the principle to individuals within a species. The absolute brain size is correlated with the intelligence of a species, but that does not mean that intelligence is causally determined by brain size. Now I’m only speculating, but maybe a change in brain size is useless or even harmful unless it is accompanied by a change in the number of neurons or overal neuronal activity.
If your hypothesis were correct, we should expect higher intelligence from people with megalencephaly.
http://voices.yahoo.com/megalencephaly- … 88259.html
But even if brain-size is a good predictor of individual intelligence, you have not shown that such differences, if existent, are genetic.quote DavidSims:
Did they somehow control for stereotype threat?
Even in adoption studies, there could be differences due to stereotype threat or even nutrition in the womb.
http://www.scientificamerican.com/artic … mb-to-tomb
October 26, 2013 at 7:38 am #114626quote DavidSims:
There are vast oceans of positive evidence that "the races are equals." But for a racist ideologue only the evidence that comports with his ideology is acceptable. In fact you’re the one making the extraordinary claim, despite abundant evidence to the contrary, that the races are not equal. Therefore you have the onus to prove your thesis. Your hypothesis is considered quackery, scientific racism and pseudoscience that is well out of the mainstream of scientific and academic thought. So the ball is in your court. Prove it. For example, can you identify any intellectually difficult activity that one race can perform that other race cannot perform? Brain surgery? Rocket science? Quantum physics? Or do you have evidence that some races are lacking in intelligence genes that other races have in greater abundance?
Put up or shut up.quote :
You want me to prove that races are equal? No, you prove that races are unequal. I find it deliciously ironic that the people arguing for white supremacy in intelligence are usually not very intelligent themselves. Black people are certainly capable of genius, super genius and extraordinary intelligence. Black people are able to perform any function that whites and Asians can perform regardless of how intellectually rigorous that function is. Despite all of this direct evidence from the real world, you are insisting that black people are less intelligent. Since you are challenging vast tides of irrefutable and incontrovertible evidence, you have the burden of proof. I want real proof that enjoys mainstream scientific and academic consensus. Don’t give me Rushton, Lynn and Jensen. Those are widely debunked pseudoscientic quacks that no one takes seriously other than a tiny fringe of white racists.quote :
The correlation between brain size and intelligence is extremely weak. Nevertheless, there is absolutely no evidence that black people have smaller brains on average than any other race. You have evidence? Post it. Cadaver studies? Those are irretrievably flawed and they’ve been debunked by such eminent scientists as Phillip Tobias:
A critical review is given of those factors which may be accompanied by variations in brain weight, viz. sex, body size, age of death, nutritional state in early life, source of the sample, occupational group, cause of death, lapse of time after death, temperature after death, anatomical level of severance, presence or absence of cerebrospinal fluid, of meninges, and of blood-vessels. Valid comparisons between the brain-weight of human populations should take all, or several, of these variables into account; however, published studies have not done so, despite claims to the contrary. The ideal sample is from subjects who have died suddenly without prior disease: while three such samples are on record for Europeans, none has been recorded for Negroes. The brain-weight of healthy Negroes is not known. Most published interracial comparisons are invalid. The histological, chemical and functional counterparts of big and small brains in modern man are not known. Published interracial comparisons of thickness of the cerebral cortex and, particularly, of its supragranular layer, are technically invalid: there is no acceptable proof that the cortex of Negroes is thinner in whole, or in any layer, than that of Europeans. It is concluded that vast claims have been based on insubstantial evidence.
http://onlinelibrary.wiley.com/doi/10.1 … 3/abstractquote :
Black Africans express the greatest variability in skin coloring. Their skin tone shades range from nearly black to nearly white. I believe Africans also express the greatest variability in height, from the extremely tall Dinka people to Pygmies. You’ve unwittingly stumbled upon the fact that black Africans cannot be pigeonholed into some artificially contrived "Negroid" archetype given their tremendous variability in phenotypic traits. So there is no "black brain size." You’d have to conduct a comprehensive study comprising the multitudinous African ethnic groups in order to arrive at an average brain size for blacks. No such study has ever been done. But if I had to hazard a guess, I’d say that blacks, on average, have the largest brains for the reasons I enumerated in an earlier post.quote :
So prove it. Why are you working so hard? Shouldn’t such inequality, if it was real, be eminently provable and obvious? I’m 100% black. The notion that you’re superior to me is laughable in the extreme. In fact all my life, when in the company of whites, if anybody was superior it was I.quote :
This is complete nonsense that is thoroughly debunked by Richard Nisbett, a real scientist:
Why rely on such misleading and indirect findings when we have much more direct evidence about the basis for the I.Q. gap? About 25 percent of the genes in the American black population are European, meaning that the genes of any individual can range from 100 percent African to mostly European. If European intelligence genes are superior, then blacks who have relatively more European genes ought to have higher I.Q.’s than those who have more African genes. But it turns out that skin color and “negroidness” of features — both measures of the degree of a black person’s European ancestry — are only weakly associated with I.Q. (even though we might well expect a moderately high association due to the social advantages of such features).
During World War II, both black and white American soldiers fathered children with German women. Thus some of these children had 100 percent European heritage and some had substantial African heritage. Tested in later childhood, the German children of the white fathers were found to have an average I.Q. of 97, and those of the black fathers had an average of 96.5, a trivial difference.
If European genes conferred an advantage, we would expect that the smartest blacks would have substantial European heritage. But when a group of investigators sought out the very brightest black children in the Chicago school system and asked them about the race of their parents and grandparents, these children were found to have no greater degree of European ancestry than blacks in the population at large.
Most tellingly, blood-typing tests have been used to assess the degree to which black individuals have European genes. The blood group assays show no association between degree of European heritage and I.Q. Similarly, the blood groups most closely associated with high intellectual performance among blacks are no more European in origin than other blood groups.
http://www.nytimes.com/2007/12/09/opini … d=all&_r=0
Beyond that, I’ve already provided conclusive evidence in an earlier post that the most successful black people in the United States are, indeed, first and second generation Africans who have no trace of European admixture whatsoever. In fact they are vastly more successful than whites in terms of academic and occupational attainment.quote :
Notice all the "experts" you’ve introduced to this debate are/were avowed racists who have been censured by their peers for sloppy, fraudulent and deceptive research. They are/were on the payroll of the neo-Nazi Pioneer Fund. What did you expect their findings to say? Do you think the Pioneer Fund would continue to pay them if they didn’t toe the party line?
Do you have any legitimate and credible scientists or academics who support this racialist ideology? Is it taught in schools? Does mainstream science and academia believe that there is a genetically influenced racial hierarchy in intelligence? Of course not. Yet you’re asking those who hold the opposing (mainstream) view to prove you wrong. LMAO. 😆quote :
Wrong. See above.quote :
According to Richard Lynn Africans are clinically retarded. Yet we know based on real world evidence that this is absurd. Africans master multiple languages and handle their affairs like normal, well-adjusted people. Even teenage Africans armed with little more than a Yahoo account are able to outsmart and clean out the bank accounts of the very best and brightest white people in America and Europe. It’s a multi-billion dollar industry. They’ve outsmarted and cleaned out white medical doctors, government officials, presidents of banks and CEO’s of various companies. How can "imbeciles" outsmart the allegedly superior race?quote :
Lynn is a joker and a fraud. The entire cottage industry of race realism, scientific racism, white nationalism (or whatever you want to call it) is driven precisely by cherrypicked correlations and confirmation bias. You and your heroes simply dismiss or reject any piece of information that doesn’t comport with the ideology you are trying to advance. It certainly not a search for truth, because your minds are closed shut to countervailing evidence.
Oh, and I know you’ll trot out the timeworn adoption study bullshit. So allow me to preempt that now. This is Nisbett from the same article as above:
The closest thing to direct evidence that the hereditarians have is a study from the 1970s showing that black children who had been adopted by white parents had lower I.Q.’s than those of mixed-race children adopted by white parents. But, as the researchers acknowledged, the study had many flaws; for instance, the black children had been adopted at a substantially later age than the mixed-race children, and later age at adoption is associated with lower I.Q.
A superior adoption study — and one not discussed by the hereditarians — was carried out at Arizona State University by the psychologist Elsie Moore, who looked at black and mixed-race children adopted by middle-class families, either black or white, and found no difference in I.Q. between the black and mixed-race children. Most telling is Dr. Moore’s finding that children adopted by white families had I.Q.’s 13 points higher than those of children adopted by black families. The environments that even middle-class black children grow up in are not as favorable for the development of I.Q. as those of middle-class whites.
http://www.nytimes.com/2007/12/09/opini … d=all&_r=0
October 27, 2013 at 9:53 pm #114628
A bit off topic, but I will suggest that intelligence is maintained in all Homo sapien populations because intelligence is useful in any environment where the food supply permits extra brain growth.
If we ever get evidence that—environmental influences equal—African genetics are generally more favorable to the development of intelligence, I would pose the hypothesis that it’s due to (a) gene flow throughout a larger population (the population of Africa) allowing for more rapid evolution or (b) restrictive dietary options in the colder European climates.
November 3, 2013 at 4:57 am #114672AnnijParticipant
To begin with, race is a myth. So, without getting all researchy and endlessly giving air time to this silly question, we simply have to remember we are part of the same species, meaning when we all breed together our progeny too can breed. I think that settles it. 🙂
January 24, 2014 at 4:26 am #114997EgadParticipant
I lived my early years in a part of the world where there were very few Blacks. I later relocated to the southeastern USA, where the population is about half Black. I saw above that one study showed an average IQ of about 85 for blacks and 103 for whites, with IQs of mixed corresponding to their mixture. Remember, those numbers are averages. There was a wide range in each race. The results of that study have been rejected by some who claim that ALL "races" are equal, not just Black/White. I now live in a neighborhood that is about equally distributed racially, and associate with each race . I had been here only a short time when I noticed the very obvious deference in the IQs, as shown by the study mentioned before. One has but to look and listen with a fair mind to notice the difference. My 2$ worth. (Inflation) Dr. Jim.
January 25, 2014 at 8:14 pm #115002quote Egad:
No one cares about your personal anecdotes. Do you know how many dumb whites I’ve come across? I don’t jump from that to the conclusion that whites are generally stupid. Besides, your perceptions of those blacks are colored by your prejudices. And let’s not forget 400 years of slavery and oppression. Surely even you can see how that might negatively impact the adaptation of black people to certain of the norms of the majority culture (which you are incorrectly perceiving as lack of native intelligence).
What’s more, your mixed-race theory is a well-known canard. First of all, American blacks are already mixed. Secondly, there’s absolutely no evidence that higher levels of white admixture in blacks contributes to higher intelligence. In fact the lack of such evidence is precisely one of the points used to debunk the idea of racial hierarchies in intelligence. That is, if whites are smarter than blacks then we should expect black-white hybrids to be more intelligent than pure blacks, and they’re not. In fact in my post prior to this one I quote Richard Nisbett discussing this very matter. It’s highlighted in blue. I suggest you read it.
January 25, 2014 at 9:26 pm #115003quote TJJ:
Thank you for the enlightening post. What you have posted resonates with my observations and personal experiences. I am white, and I have lived very closely with other races in a wide variety of circumstances.
January 25, 2014 at 9:41 pm #115004quote Annij:
Nonsense! You chant a liberal mantra and claim it to be science? Wolves, coyotes, and dogs cam all breed and produce fertile offspring. You are aying that they are all the same. Turkeys, chickens, pheasants, and Pea fowl mixes can produce fertile offspring. An infant can tell significant differences between the various races. LOL! What happens to the minds of PC liberals that renders them unable to observe reality accurately? Too much chanting???
January 25, 2014 at 10:22 pm #115006quote GrowingAtrophy:
Do you have anything besides yelling "liberal" at anyone who disagrees with you? Are you here to debate or to recite trite catch phrases you gleaned elsewhere on the Internet?
An infant can distinguish between people alright. It, for example, knows its mother from its father. It knows its fat aunt from its skinny aunt. What exactly is your point with respect to infants? In fact what is your point generally? Are you trying to imply a racial hierarchy in intelligence? If so, how do you account for all the black people that are smarter than you? In fact what about the black people that are smarter than you and anyone you know, have ever known or will ever know?
January 26, 2014 at 12:52 am #115007
You dare to point toward "trite catch phrases"? Then you ignore completely my argument about species.
I do not believe that you are so ignorant that you do not know what an average IQ is and how Average IQs overlap. I have people in my family who have IQs lower than the average IQ of an American black, but that doesn’t change the average IQ of American blacks. I, personally have a 25-30 point IQ over the average American black, but that has nothing to do with any races average IQ, and certainly, some blacks are more inteligent than I am. That does not affect any races average IQ. You cannot be so silly as to think that blacks average the same IQ as Whites, or Asians…..Or American Jews. I hope you aren’t.
If all of the races had equal IQ averages the reigning PC Social Police woud have tesed us all and proven it in the 60s. Instead they seek refuge in shifting arguments about culture and environment and the unreliability of tests. The fact is that everyone is not equal, and no amount of social engineering can make them equal. Small minds crippled by the politically correct social sciences agendas have too much invested to embrace actual science, fact, and truth. My first degree was in Sociology in the 70’s. I personally experienced the suppression of critical thought that created emotion based arguments like yours.
If we were all the same, this wouldn’t happen.
" Yet by nine months, babies react more swiftly to their own race than others: they differentiate more readily between faces and match emotional sounds with facial expressions faster. A study from the University of Massachusetts Amherst, published in May in Developmental Science, showed that the younger infants use only the frontal part of the brain for the task. By nine months, babies also recruit the occipital-temporal region, where recognition happens in adults. "
http://www.scientificamerican.com/artic … -see-race/
January 26, 2014 at 1:46 am #115008quote GrowingAtrophy:
What about species? How is any of that relevant? How does it support your theories?quote :
But blacks do average higher IQ’s than whites and Asians according to "work" done by such luminaries of scientific racism as Richard Lynn. 😆 I suggest you take a look at the list of IQ by nation, which I’m sure you’re familiar with:
http://www.photius.com/rankings/nationa … ranks.html
Notice all the white and Asian countries whose IQ averages fall below the IQ average of black Americans. Countries such as India, Lebanon, Saudi Arabia, Iran, Syria, Algeria, Pakistan, Morocco, etc., all score below black Americans. This wouldn’t happen if your racial hierarchy in intelligence theories had any validity. As a matter of fact, adjusted for 400+ years of brutality and cultural ostracization black American IQ is actually significantly higher than white American IQ. So I don’t know why you’re pointing to the IQ average of blacks in America as proof of your pseudoscience. By every measure, black American IQ debunks your entire worldview.quote :
Yeah, well I just proved that American blacks have higher IQ’s than whites and Asians, even in spite of 400+ years of slavery and oppression. 🙄quote :
Well, the tests have often proved to be unreliable if not outright fraudulent. Let me ask you a question, how would you score on an IQ test given in the Zulu language and steeped in Zulu cultural references? Would that be a reliable test from your perspective?quote :
That’s true on an individual level, regardless of race. And you should couch it that way rather than suggesting that entire races of people are inferior or superior.quote :
Well, the problem is you people never have any science. It’s all scientific racism and pseudoscience. Where is your science? I dare you here and now to provide your science. Show me. In fact you have no science, so stop claiming you do.quote :
It’s actually people like you who suppress speech. One of your pet tactics is to describe as a liberal anyone with a sensible, scientifically correct view of these matters. Or you’ll claim there’s a vast conspiracy driven by political correctness that keeps your laughable views from gaining currency. You’re also the ones driven by emotion. Just read your posts. They’re emotional rather than scientific appeals. Where’s your science?quote :
Babies react to familiar things. That means that a white baby raised around black people will react more swiftly to black people than to white people. My friend, look to your own IQ.
January 26, 2014 at 8:39 pm #115009
Anyone else notice that the people I’m debating never seem to come back to defend their so-called positions? That pretty much tells us all we need to know about the flimsiness of their entire ideology. An ideology that wilts under a little bit of opposition is definitely unsound to say the least.
February 11, 2014 at 4:38 am #115043EgadParticipant
Seth 90210: you completely missed my point: I said just look around you with an open mind. If you do you will arrive at a conclusion befitting your own IQ and past experiences. I repeat-open mind. We all descended from the same line, then changed over the Eons, into different "races" because of geographic isolation. Humans are just one example. Just look at the geographic distribution of other native animals, even virus, such as that causing AIDS. (HIV). I also alluded to the frequency distribution curve. There are even a few Whites who can play football and box, just as there are some articulate Black men, like our Pres. Read your local newspaper. Notice any racial distribution of crime? Google Hartsville toddler death for an example!!! Dr. Jim.
February 16, 2014 at 9:35 pm #115055quote Egad:
This is complete gibberish. Also, I find it odd that you’re asking me to have an open mind when your mind is seemingly hermetically sealed. A bigot, by definition, is someone with a closed mind.quote :
Yeah. So what?
Btw, it’s obvious your "doctorate" is neither in anthropology nor genetics. You simply don’t know what you’re talking about. In terms of evolutionary time scales humans had been isolated a relatively short time. We’re talking a few tens of thousands of years at most and even then there had been continuous gene flow between different populations of humans. This is certainly not enough time for discrete differentiation to have occurred in any complex trait like intelligence. If we look at Homo sapiens and Neanderthals we see the beginnings of a genetic split about a half million years ago after at least 1 million years of separation. So that gives us a sense of how long it takes for something dramatic to happen. In other words, a very long time — much longer than the human experience.
But again, what is your point? We don’t see any human population clusters with superior hearts or spleens, so why would any population of humans have superior brains? Can you identify a single credible neurologist or neurosurgeon who can even distinguish one human brain from another ethnically or racially? No, you cannot. Are you saying that isolation caused some human groups to be smarter than others? Well that’s wrong too, given the tremendous inter-population overlap in intelligence. How do you account for the fact that genius and super-genius are found in every single population cluster? How do you account for the fact that any human, regardless of race or ethnicity, can adapt and assimilate any other human culture? Just look at the United States for proof. How do you account for the fact that all "races" of humans are sexually compatible and able to produce viable offspring? You see, these are the facts and then there are your delusions. But the world is governed by facts, not delusions. 😀
Even other "races" of animals that had been isolated from each other much longer than humans show no appreciable variations in intelligence regardless of habitat or range. Snow leopards are not more intelligent than African leopards. Siberian tigers are not more intelligent than Bengal tigers and so on. Big hint: if it didn’t happen in nature, it ain’t gonna happen among humans.quote :
This is totally irrelevant to the topic. Nobody’s arguing that there aren’t differences between human population groups. There are even differences between your family members. However, most of the differences between human "races" are expressed in the form of superficial variation, things like skin and hair color. Moreover, well over 90% of human genetic variation occurs within "races" or local population groups rather than between them. It is unimaginably daft to suggest that a complicated trait like intelligence is going to be addressed in the tiny .01% sliver of genetic divergence between human groupings. In fact science has demonstrated that intelligence is a polygenic trait and none of those genes appear to reside within the aforementioned .01%.
Okay, I acknowledge differences. Now, what’s your point? That some groups are smarter? Where’s your evidence? And what about all the contradictory evidence? In fact why are you struggling so mightily? Shouldn’t such racial hierarchies in intelligence be self-evident and glaringly obvious? I’m assuming you’re white. Well, I’m black and I think it’s pretty obvious that I’m smarter than you. Hate to break it to you.quote :
Distribution curves don’t reflect genetics. IQ can be learned. IQ scores are not frozen in time for all eternity. IQ rises and IQ gaps close. So, again, what is your point?quote :
A lot more whites would play football and box if they chose those paths. You only need to look at the history of football and boxing for confirmation. You only need to look at present day Eastern European whites for confirmation that whites, indeed, can box and box very well. You do know that there are whites outside of the United States, correct? And blacks as well. Are you cognizant of this? And any person that wants to be articulate, whether they are black or white, simply needs to make the effort and educate himself. How is articulateness or lack of same a mark of racial genetic superiority or inferiority?quote :
Only a complete imbecile would think that crime is somehow genetically determined. If you really think that blacks are more criminally predisposed than whites then you haven’t known very many whites. Many people can argue very persuasively that whites are infinitely more criminally inclined than blacks. And they can provide proof to support that argument in the form of historical crimes, mass-scale crimes in which entire continents and millions of people were destroyed. Or present day financial and white collar crimes. Or crimes against children of a deviant sexual nature, here and abroad via child sex tourism. Or mass shootings and serial killings. Oh, you mean street crime? Watch old newsreels. All the muggers, burglars, robbers and killers are white. And presently in Eastern Europe they’re all white. So it’s really not about genes, is it?
You want me to Google a toddler death? Are you for real? What about all the white people who’ve killed their toddlers? What about the white women who drowned her kids in her car and then tried to blame it on a black man? And that’s just the very tip of the iceberg.
Dr. Jim? LMAO. I want to know where you got that doctorate. 😆
March 13, 2014 at 4:13 am #115195quote Seth90210:
Good point that I would like to add to! The average IQ should be affected by environment and genetics, and the international variations in IQ should reveal how strongly environment affects these averages. The more variation that is associated with environmental influences, the less accurately we can estimate the effect of any genetic differences.
The image depicts roughly what I am saying. As the variation associated with environment increases, the odds ratio approaches 1:1, a 50/50 split of probability regarding which group is overall genetically superior in terms of the predisposition toward intelligence.
March 13, 2014 at 11:34 pm #115199
Apparently the genetic influences on IQ are at least as strong as the environmental influences, but this psychologytoday article’s mention of genetic "multipliers" challenged my previous understanding of genetic influences (denoted by A in the twin study ACE model). If skin color is a determiner of IQ and skin color is genetic, that would be counted as a genetic influence on IQ in a twin study.
May 23, 2014 at 4:23 am #115265quote wildfunguy:
No one doubts that genetics play a vital role in intelligence. But we’re all creatures of genetics, aren’t we. Unless you’re suggesting that some "races" have better genetics than others. If that is indeed the case then the most likely candidates for that designation would be black Africans:
European-American populations are less genetically diverse and have more potentially harmful genetic variations than African-American populations, according to an international team of researchers.
The findings suggest that human migrations may have affected genetic diversity and that a population "bottleneck" may have been involved in the original settlement of Europe
http://news.nationalgeographic.com/news … ution.html
July 30, 2014 at 8:20 pm #115336quote Seth90210:
I wasn’t suggesting that skin color directly effects intelligence. I was suggesting that because skin color, a largely genetic trait, affects how a person is treated, an environmental effect, it will be counted as a genetic influence under the ACE model even though melanin-depositing genes are only expressed as lower intelligence if the culture discriminates against people with more melanin. It is the interaction between genetics and environment that makes it so difficult to fully understand how they each contribute to who we are.
Alas, suffice it to say, this is controlled for if the non-identical twins are always the same skin color too, which is usually the case since people usually select mates of roughly the same color. There could however still be a small effect on the study results.
My post before the last post was somewhat superficial. The different averages would only suggest a greater probability of overall "worse" genetics if we had no further information. In this case, however, we have the further information that African-americans have been mistreated for a long time, which would lead to a lower average IQ regardless of their true genetic potential, nullifying the reasoning above.
July 30, 2014 at 8:50 pm #115337quote Seth90210:
Allele frequencies vary between poopulations. The question is not whether there’s a difference (in genetic IQ predisposition), but how large that difference is.
I think the adoption studies suggest that the difference is negligible, regardless which way it goes. The adopted black children had almost the same average, but the researchers couldn’t control for differences during fetal development, and there’s also the questino of statistical significance.
July 31, 2014 at 10:29 pm #115339
I was wrong about the adoption studies.
In addition to prenatal environment, the studies also fail to control for social environment.
https://en.wikipedia.org/wiki/Minnesota … dy#Results
table of the Flynn-effect corrected results, 3rd table under Results…
It’s interesting that the adopted children had a larger drop in IQ from 7 to 17, but the average drop for the adopted non-whites ((55*12.2+12*4.9+21*7.7)/(55+12+21)=10.1) was equal the drop for the adopted whites (10.1). The drop was smaller for the adopted blacks specifically (7.7), which could be due to the decline with age in the effect of "pre-adoption variables".
According to the Wikipedia article, Loehlin suggested prenatal effects, noting that among the adopted interracials, 66 of their 68 biological mothers were white. You’ll notice that this group’s IQ was only below the adopted whites by 6 and 8 IQ points, whereas the adopted blacks were below by 20 and 18 IQ points, more than twice below at age 17 and nearly four-times below at age 7.
Suffice it to say, the adoption studies results were influenced by many non-genetic variables, and it shouldn’t be surprising that the adopted blacks still scored lower on IQ tests.
October 27, 2014 at 9:12 pm #115515josemParticipant
I think there is no correlation between brain size and IQ level. If compare brains of whale and elephant with humans, ours is too small. But we have very high intelligence. I think some connections between neurons or some unknown factors determine intelligence.
February 25, 2015 at 2:37 am #115665quote CandyTon:
1. There’s no such thing as a "black brain." So your brain size claim has no validity.
2. The 70 IQ claim for Africans is a well-known fraud.
October 6, 2015 at 5:10 am #115788DrBarbParticipant
The physical body’s brain has nothing to do with IQ. It is the result of the Spirit fused with the body at birth. Remove the Spirit from the body and the body drops into a comma.
What is missing from the south african human speies is the absence of the Adam and Eve genes, the stablelising evolutionary genes for young spirits that are evolving on their assigned planets. Adam and Eve’s Evolutionary Contribution was interrupted and time shortened.
Same with asiams – missing adamic genes. You will soon detect the Adamic Gene.
Negative force spirits can be detected by a minus level EM generation of energy. A spiritual-souil who has not betrayed belonging to God the Father and Mother measures in the plus level.
Islamics are not worshipping the four members of the Family of God, therefore, can never become Immortal. Those Islamics that murder will be returned to the early animal realm that allows them to lose their current memory and start over.
All animals are pre-human evolutionary biological forms. At this time the Spirit learns how to use eyes, ears, and keep the eventual biological cells function.
Never ge tazared, as it destroys your spirit’s memory and in next life, autism or cells that do not function. Tazar your hard drive for proof. That much destruction to your own Spirit.
September 3, 2016 at 9:22 pm #116088jon123Participantquote [url=http://www.Infantigo.xyz/:
I totally agree with you because correlation of brain size and IQ level makes no sense at all.
September 7, 2016 at 12:04 pm #116095
There is one big problem which destroys all the ‘well-researched’ material and even the very heading of this topic.
When using people for the kind of research mentioned above, how do researchers choose their subjects? In other words, who is an ‘Asian’, who is an ‘African’ and who is a ‘European? And who is an ‘Australian ‘Aborigine’?, a ‘Melanesian’, a ‘Sub-Saharan African’ and an ”African-American’?
There is no way you can draw boundaries round these groups, so no way any ‘averages’ can be stated from measurements.
Obviously, we know that researchers choose ‘Africans’ from people who have dark complexions. But where does this term end? Who is
too light to ‘qualify’? And who are ‘true’ ‘Europeans’? Are North Africans, with dark complexions, but ‘European’ features part of this group? Why do researchers assume that dark complexions mean different ‘racial’ qualities?
There is only one race, the Human Race and I am not being ‘political’ but trying to show that all features, like skull size, brain size (by this do we mean volume, circumference, area of surface folds, weight?), nose width, curliness of hair etc etc are distributed throughout the species. These features are on a scale which is normal to the species.
I would argue that you cannot divvy up any species into ‘races’, ‘populations’ etc and there is even a case to say that the sexes are also not amenable to being measured as a group, because there are all sizes of men and women throughout the species.
September 8, 2016 at 11:34 am #116100
I cannot find my recent reply so I am making the same point again.
All the voluminous and detailed research on this subject is destroyed by one vital problem. When researching the brains of different ‘groups’ of humans, (‘races’, ‘populations’) how do researchers choose their subjects? In other words, who is an ‘African’, a ‘European’, an ‘Aborigine’, a ‘Melanesian’, a ‘Papuan’ and so on.
Obviously, the researchers classify as ‘African’ anyone who is of a dark complexion. (This assumption, leading the researchers to assume and to claim actual genetic differences is just a function of their pre-assumed prejudice).
But how light can my complexion be before I qualify to enter another category, say ‘European’, meaning ‘white’?
And what about all those people who are light brown, middle brown and so on??
There is no way that boundaries can be drawn round ‘racial’ groups, so no way to gain statistics and averages.
The human brain is just that, the human brain, which every member of the species is born with.
Like every other feature of the species, the brain grows within the normal range of growth of the species, which is roughly a bell curve, with some people having the smaller end of the measurements (but perfectly normal) most others in the middle size and a small number at the large end.
If any person with a dark complexion (or strong epicanthic folds, or curly hair, or a small nose, or freckles) can gain top class degrees whatever the actual measurements of their brains, by circumference, volume, surface folds, or weight, and of course they do, we know that they are the same as every other person on the planet.
Isn’t it time that (usually) so-called ‘white’ people stopped trying to prove their ‘superiority!?
September 24, 2016 at 10:51 am #116139
All research involving ‘races’, ‘populations’, ‘groups ‘ethnicities’ and so on fails to have validity because the subjects of the research cannot be defined or put into boundaries.
I have just looked at some research regarding the Y-chromosome, ‘Prospective assessment of Y-chromosome micro-deletions and reproductive outcomes among infertile couples of Japanese and African origin’, Paul E. Kihaile et al, 2007.
In the research material ‘Western populations’ were also mentioned.
But who is ‘Japanese’, ‘African’ (specifically in this case, Tanzanian) or ‘Western’?
no doubt the latter were chosen from what used to be called ‘white’, while the ‘African’ were perceived to be ‘black’ and the ‘Japanese’ were people who ‘looked’ Japanese.
These categories are just subjective perceptions; they cannot be used to find statistics because you cannot draw boundaries round any one group. How ‘black’ do you have to be to be in the ‘African’ group etc.?
No genetic differences can be said to hold for any so-called race and I challenge researchers to say how their subjects were chosen.
February 2, 2017 at 6:40 pm #116158joemastersParticipant
I will give a short boring answer. The size of the brain does not equal intelligence. It is the rate of growth, the % used, and how it is developed from fetus to 3 years of age. Very intelligent adults had faster developing brains and more stimuli as they were growing thus making their brain more capable of long term memory and solving problems.
February 14, 2017 at 5:14 pm #116172
There is only one brain, the human brain. It can be larger or smaller within the normal human range; its dimensions (weight, depth, circumference etc) are a rough summary of samples of the adult brain and, of course, there is the surface area, with multifarious complex folds.
There can be no ‘black’ or ‘white’, ‘male’ or ‘female’ brains, because all brains develop in the same way, from the fertilized egg, during the human embryological pathway and for a few years after birth. This development is within the normal human range (some malformations of chromosomes may give non-normal development leading to impairment). In the same way, there are no black or white, male or female livers, hearts, skulls, noses, teeth, lungs or eyes, for example.
There can be no comparisons of brains or brain-power between ‘races’, (‘black’ or ‘white’) because firstly, there is no way that boundaries can be drawn to distinguish ‘races’. Who is ‘black’ and who is ‘white’? Researchers, trying to do this sort of comparison, use ‘a priori’, subjectively-based appearance to identify which ‘race’ a person belongs to, so any ‘statistics’ are the result of an arbitrary grouping of people.
People of dark complexion gain degrees, become Professors, lead countries, do maths etc etc, (people named ‘Aboriginal Australians’, often depicted as a distinct ‘race’ of ‘low ability’, manage nowadays to do all these things if given the opportunity, thus showing that a person’s complexion has no bearing on brain power. The same is true of any human attribute.
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