Elsevier

Medical Hypotheses

Volume 71, Issue 5, November 2008, Pages 629-640
Medical Hypotheses

Editorial
James Watson’s most inconvenient truth: Race realism and the moralistic fallacy

https://doi.org/10.1016/j.mehy.2008.05.031Get rights and content

Summary

Recent editorials in this journal have defended the right of eminent biologist James Watson to raise the unpopular hypothesis that people of sub-Saharan African descent score lower, on average, than people of European or East Asian descent on tests of general intelligence. As those editorials imply, the scientific evidence is substantial in showing a genetic contribution to these differences. The unjustified ill treatment meted out to Watson therefore requires setting the record straight about the current state of the evidence on intelligence, race, and genetics.

In this paper, we summarize our own previous reviews based on 10 categories of evidence: The worldwide distribution of test scores; the g factor of mental ability; heritability differences; brain size differences; trans-racial adoption studies; racial admixture studies; regression-to-the-mean effects; related life-history traits; human origins research; and the poverty of predictions from culture-only explanations. The preponderance of evidence demonstrates that in intelligence, brain size, and other life-history variables, East Asians average a higher IQ and larger brain than Europeans who average a higher IQ and larger brain than Africans. Further, these group differences are 50–80% heritable. These are facts, not opinions and science must be governed by data. There is no place for the “moralistic fallacy” that reality must conform to our social, political, or ethical desires.

Introduction

When one of the greatest biologists of the 20th century, Nobel-Prize winner James Watson, noted that people of African descent average lower on intelligence tests than do Europeans and East Asians, he was excoriated by the mass media and elements of the scientific elite and forced to retire from his position as Chair of the Cold Spring Harbor Laboratory [9], [34]. Watson’s treatment was especially egregious given that, in point of scientific fact, more than a century-and-a-half of evidence corroborates his statement. Moreover, supportive new data and analyses appear regularly in mainstream, peer-reviewed journals in the relevant scientific disciplines. Evidence to the contrary is exceedingly weak. Most of the opposition to the genetic hypothesis consists of mere moralizing and worse, the creation of a threatening and coercive atmosphere incompatible with academic freedom, free enquiry, and the civil liberties of a truly democratic society. An enormous gulf separates the politically correct gatekeepers and enforcers from true experts in the behavioral sciences.

Nor is Watson’s case unique. He is but the latest in a long line of academics that have been pilloried and defamed (detailed accounts given in Hunt [20]). The others include Nobel-Prize winner William Shockley, Hans Eysenck, Linda Gottfredson, Richard Lynn, Richard Herrnstein, Charles Murray, Christopher Brand, Glayde Whitney, Helmuth Nyborg, and Tatu Vanhanen. The present writers too have endured their share of attacks. The taboo on race will surely become a major topic of investigation by sociologists of knowledge. There is no parallel to it in the history of science. It is uniquely imposed, mainly through self-censorship, by members of the Western intelligentsia in their own academy – which prides itself on a tradition of academic freedom, open inquiry, and the unfettered discovery, systematization, and pursuit of knowledge and its dissemination to the general public.

Despite the chilling effect described, we (and the others) have persevered in part because of the great importance of the topic, the fascinating data it provides, and the theoretical issues it raises [21]. One of us (JPR) traveled to South Africa to collect new IQ data from highly-selected Black students at the prestigious University of the Witwatersrand in Johannesburg. Seven studies were published based on these data yielding a median IQ of 84 (range 77–103). Assuming that African university students are 1 standard deviation (15 IQ points) above the mean of their population, as university students typically are, a median IQ of 84 is consistent with a (very low) general population mean of 70 [48].

Because many consider the race–IQ hypothesis incendiary, it is essential to thoroughly examine all the relevant data. We did this in our 60-page review, “Thirty Years of Research on Race Differences in Cognitive Ability,” which was published as the lead article in the June 2005 issue of Psychology, Public Policy, and Law, a journal of the American Psychological Association [51]. In the current article we summarize and update those findings (more complete statistical details and references can be found there). Again, the preponderance of evidence argues that it is more probable than not that the genetic contribution to racial group differences in intelligence, brain size and other life-history variables is between 50% and 80%. A good introduction to the issues involved is Bartholomew [1].

On the basis of the 10 research categories listed below, we concluded that the mean 15-point Black–White IQ difference in the US is about 80% heritable and that the 30-point African/non-African IQ difference is about 50% heritable (much of the balance being attributable to cultural and nutritional differences). The evidence demonstrates that: (1) the mean IQ around the world is 106 for East Asians, 100 for Whites, 85 for US Blacks, and 70 for sub-Saharan Africans; (2) race differences are most pronounced on the more g-loaded IQ subtests (g being the general factor of mental ability or first principal component; it picks up the “active ingredient” in intelligence tests); (3) race differences are most pronounced on the IQ subtests whose scores show the most heritability; (4) racial differences in brain size parallel the IQ differences; (5) people of mixed-race ancestry average IQ scores intermediate to their two parental populations; (6) trans-racial adoption studies show that Black, mixed-race, and East Asian children raised by White parents have IQs closer to the average of their biological parents than to the White mean; (7) people’s offspring and siblings show regression to their respective racial IQ means; (8) the races differ consistently across 60 related life-history traits; (9) the racial IQ differences agree with the latest accounts of human origins (that is, the out of Africa model); and finally (10) environmental explanations of racial IQ differences have been tested and repeatedly shown to be inadequate.

Section snippets

Black–White IQ differences are found worldwide

National IQs have been reported for 192 countries around the world [30], [32]. The results show that the average IQ for East Asians centers around 106; for Whites, about 100; for US Blacks about 85, and for sub-Saharan African Blacks about 70 (Fig. 1). The same rank-order of race differences is found for “culture-fair” tests and reaction-time measures. Reaction-time tasks are so easy that all children can do them in less than one second [25], [26]. More intelligent children, measured by

Race differences are most pronounced on the more g-loaded components of tests

Charles Spearman [59] coined the term g for the general factor of mental ability (or “general intelligence”). A test’s g loading is the best predictor, not only of school grades and workplace performance, but also of all the other indicators and correlates of intelligence – including biological variables such as brain size, reaction times, and heritability estimates as calculated from twin studies [25]. Race differences are repeatedly found to be higher on more g-loaded tests.

g is the “active

The gene–environment architecture of IQ is the same in all races

Studies of Black, White, and East Asian twins have shown that the heritability of IQ is about the same in all races (50% or higher). There has been no indication of any special cultural influence – such as extreme deprivation, or being raised as a visible minority – at work in one group and not in the others. If poverty, slavery, and White racism had operated to suppress Blacks’ natural levels of intelligence, it would make the heritability of their IQ scores substantially lower than the

Brain size differences

Larger brains are more intelligent because they contain more neurons and synapses and can process information more efficiently. Two dozen studies using magnetic resonance imaging (MRI) have shown that brain size is related to IQ differences (within-race) with a correlation of about 0.40. This is much higher than the 0.20 correlation found using indirect head size measures, though the latter correlation is also reliable and significant.

A functional relation between brain size and cognitive

Trans-racial adoption studies

Trans-racial adoption studies provide one of the most powerful methods for studying race differences. They are the human analog to the cross-fostering method commonly used in animal research. Human adoption is clearly a massive environmental intervention.

Studies of Korean and Vietnamese children adopted into White homes show that although as babies many had been hospitalized for malnutrition, they nonetheless grew to have IQs 10 or more points higher than their adoptive national norms [10], [14]

Racial admixture studies

Dozens of studies have found that lighter-skinned African Americans have average IQs higher than their darker-skinned counterparts [41]. For example, Lynn [29] examined the National Opinion Research Center (NORC) survey of a representative sample of the adult population. The 442 Blacks were asked whether they would describe themselves as “very dark,” “dark brown,” “medium brown,” “light brown,” or “very light.” The correlation between these self-ratings and a 10-word vocabulary test score was

Blacks and Whites regress toward their predicted (and different) means

Basic genetic theory predicts that the IQ of offspring will regress towards the mean IQ of the population group from which the parents come. This has been amply documented for a number of physical traits in humans and in other species. Regression-to-the-mean is seen when individuals with high IQ scores mate. Their children tend to show lower scores than their parents. The converse happens for low IQ parents; they have children with somewhat higher IQs. This is because the parents pass on some,

The riddle of the three-way pattern of race differences

On a wide variety of attributes, East Asians and Blacks fall at the two ends of a continuum [46], [64]. Whites are in the middle. In addition to brain size and IQ, this shows up on a suite of 60 other life-history variables. These include speed of maturation and longevity, personality and temperament, family stability and crime, and sexual behavior and fertility. Table 2 lists some of these differences. One striking example: Around the world the rate of dizygotic (i.e. two-egg) twinning is less

Race differences and human origins research

The current consensus view of human origins, the “out-of-Africa” theory, posits that Homo sapiens arose in Africa about 150,000 years ago and then expanded northward beyond Africa about 100,000 years ago, with a European–East Asian split about 41,000 years ago. Evolutionary selection pressures were different in the hot savanna, where Africans lived, than in the cold northern regions Europeans experienced, or the even colder Arctic regions where East Asians evolved. Thus, the further north the

Culture-only theory hypotheses fail to account for the race–IQ differences

Contrary to many hopes and some claims, the narrowing of the gap between Black–White social conditions has not led to any change in the magnitude of the Black–White IQ difference in over 100 years. Massive society-wide interventions such as ending segregation, the subsequent nationwide program of school busing to achieve racial balance, and the Head Start programs have failed to reduce the differences. Head Start programs did produce modest gains in school retention and graduation rates among

Wanted: More race realism, less moralistic fallacy

The “naturalistic fallacy,” identified by philosopher David Hume (1711–1776), occurs when reasoning jumps from statements about what is to a prescription about what ought to be.

An example of the naturalistic fallacy would be approving of all wars if scientific evidence showed warfare was part of human nature. The converse of the naturalistic fallacy is the “moralistic fallacy” – jumping from prescriptions about what ought to be to statements about what is. An example of the moralistic fallacy:

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