National Review, September 15, 1997
Mr. Rushton is professor of psychology at the University of Western Ontario in London. This article is adapted from his review in the referred academic journal Personality and Individual Differences, Vol. 23, pp. 169-180.[ The complete article can be found here. ]
"[Stephen Jay] Gould occupies a rather curious position, particularly on his side of the Atlantic. Because of the excellence of his essays, he has come to be seen by non-biologists as the pre-eminent evolutionary theorist. In contrast, the evolutionary biologists with whom I have discussed his work tend to see him as a man whose ideas are so confused as to be hardly worth bothering with, but as one who should not be publicly criticized because he is at least on our side against the creationists."
YEP, that`s the Stephen Jay Gould—Harvard paleontologist, best-selling science popularizer, Natural History magazine columnist, and media superstar—in the opinion of John Maynard Smith, one of the founders of modern evolutionary theory. Smith`s skepticism about Gould is pervasive among his peers. Daniel Dennett`s brilliant 1995 book, Darwin`s Dangerous Idea, was largely devoted to dispelling Gouldian misinformation. John Alcock, author of standard animal-behavior textbooks, recently described Gould as "consistently employing the same limited set of debating techniques and stylistic devices . . . while simply ignoring evidence to the contrary."
This civil war among evolutionists has now burst into the open. Gould struck back, with his trademark deceptive elegance, in The New York Review of Books (June 12, June 26, August 14), house organ of the New York intelligentsia that has long been his real constituency.
The point at issue between the evolutionists and Gould seems arcane. Does evolution proceed gradually or through "punctuated equilibrium"—immobility interrupted by transforming upheaval? Gould`s preference for the latter reflects his left-wing politics—for evolutionary upheavals, read social revolutions. Yet it may also be traced to his refusal to admit that systematic differences, probably evolutionary in origin, exist among human beings.
That same refusal regularly distorts Gould`s 1981 The Mismeasure of Man, now reissued in a "revised and expanded" edition (Norton, $13.95). The Mismeasure of Man (which in its first version sold 250,000 copies, was translated into ten languages, and became required reading for undergraduate and even graduate classes) dealt with questions that are delicate, controversial, and (to the scientific layman) even discomfiting: IQ, brain size, sex, and race. It did so by unscrupulously mishandling the evidence. The new version—described by the publisher as "an acclaimed classic that refutes the conclusions of The Bell Curve"—is expanded but hardly revised. It regurgitates character assassinations of deceased scientists, misrepresents their work despite published refutation, and studiously withholds 15 years of new research that contradicts every major scientific argument Gould puts forth.
Perhaps the single most devastating development for Gould: new research on brain size. Was he asleep throughout the 1990s—called, with good reason, "The Decade of the Brain"?
Gould originally charged nineteenth-century scientists with "juggling"and "finagling" brain-size data in order to place Northern Europeans at the apex of civilization. Implausibly, he argued that Paul Broca,Francis Galton, and Samuel George Morton, all "finagled" in the same direction and by similar magnitudes using different methods. 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 and that Galton caused with his "extra loose" grip on calipers while measuring heads! Yet even before Mismeasure`s first edition, new research was confirming the work of nineteenth-century pioneers. Gould neglected to mention that Leigh Van Valen had already established a positive correlation between brain size and intelligence in 1974.
Subsequently, of course, discoveries using Magnetic Resonance Imaging (MRI), which creates a three-dimensional image of the living brain, have shown a strong positive correlation (0.44) between brain size and intelligence. And there is more. The National Collaborative Perinatal Study, as reported by Sarah Broman and her colleagues, showed that head perimeter measured at birth significantly predicts head perimeter at 7 years—and head perimeter at both ages predicts IQ. Recent studies also show that head size and IQ vary with social class. It is now clear that the nineteenth-century pioneers were right.
The first of the MRI studies were published in the late 1980s/early 1990s in leading, mainstream refereed journals like Intelligence and the American Journal of Psychiatry. My colleagues and I routinely sent Gould copies and asked him what he thought. He never replied. Now he has chosen to withhold all these data from his readers.
Indeed, in the 1996 edition he deletes the very section of his own 1981 book that discussed the brain-size/IQ relation. In 1981, he had pooh-poohed Arthur Jensen`s report (in Bias in Mental Testing) of a 0.30 correlation between brain-size and IQ—but he omits this dismissal, without explanation, from the revised version. I can only infer that when Gould read Jensen`s review of his book (which he mentions), he realized that Jensen`s correlation was based on Van Valen`s 1974 review and so could no longer be dismissed as "just Jensen." And, given the weight of the new evidence, simply repeating this section verbatim would have destroyed his entire thesis. He therefore left it out.
Is it reasonable, however, to expect brain size and cognitive ability to be related? Yes. H. Haug in 1987 found a correlation of 0.479 between the number of cortical neurons and brain size in humans. Gould dismisses differences in brain size as "trivial." But a difference of one cubic inch in brain size translates into a very nontrivial millions of cortical neurons and hundreds of millions of synapses—a significant difference in mental activity and potential.
It is, of course, relationships between brain size/IQ and sex and race which, understandably, arouse the most anxiety. Some critics have even suggested a social taboo on discussion and research in these fields. That would run counter to the entire tradition of scientific inquiry. Be that as it may, it is surely indisputable that if such research is to be conducted, it must be done accurately and scrupulously. And here Gould fails again.
An absolute difference in brain size between men and women has not been disputed since at least the time of Broca (1861). Gould, however, claims that the sex difference disappears when appropriate statistical corrections are made for body size or age of people sampled. But when he used multiple regression to remove the simultaneous influence of height and age, he succeeded in reducing the sex difference by only one-third. He then invoked additional unspecified age and body parameters, claiming that if these could be controlled the entire difference would disappear.
David Ankney in 1992 questioned Gould`s methodology. He re-examined autopsy data on 1,261 American adults and found that at any given body surface area or height, men`s brains are heavier than women`s. His research—since confirmed by my own 1992 survey of 6,325 U.S. Army personnel—attributes only about 30 per cent of the sex difference in brain size to differences in body size.
Admittedly, the brain-size studies present a paradox. Women have proportionately smaller brains than men but, apparently, the same intelligence scores. Ankney suggests that the difference in brain size may relate to those intellectual abilities at which men excel—namely, spatial and mathematical ability—which may require more "brain power" than do verbal abilities. Other theories are that men average slightly higher in general intelligence than do women, and finally that these particular differences in brain size have nothing to do with cognitive ability at all, but reflect greater male muscle mass and physical coordination in tasks like throwing and catching.
Similarly, Gould denies that brain weight varies with race. He repeats verbatim his 1981 claim that Samuel George Morton—a giant of nineteenth-century American science—"unconsciously" doctored his results on cranial capacity to prove Caucasian racial superiority. Yet he must know that John S. Michael reported in Current Anthropology in 1988 that he had checked Morton`s work and found very few errors—and these not in the direction that Gould asserted. Instead, Michael found errors in Gould`s work.
In my own published work, uncited by Gould, I have shown that brain sizes vary systematically by race—but not to the benefit of Caucasians. For what it is worth, Mongoloids average about a cubic inch more than Caucasoids and over three cubic inches more than Negroids. This result has been corroborated many times since 1980, and by every available technique. And these findings are in line with the (by now) accepted IQ results: the average IQ scores for "African," "Latino,""White," "Asian," and "Jewish" Americans are 85, 89, 103, 106, and 115, respectively. Of course, whether these differences are the result of genetic or environmental influences, and whether (or to what extent) they are remediable by purposeful action—these remain matters of dispute.
GOULD`S faults extend well beyond sins of omission to include sins of commission. His "new" edition repeats the same false accusations about individuals that have been thoroughly refuted since 1981. Thus, Gould leaves unmodified his denigration of Sir Francis Galton as "a dotty Victorian eccentric." This was rightly described by Cambridge statistician A. W. F. Edwards in the London Review of Books (1983), as"a thoroughly tendentious portrait." Edwards pointed out that Gould, in a book full of references to correlation, multiple regression, principal-components analysis, and factor analysis, totally failed to inform his students that this whole statistical methodology was pioneered by Galton—and to measure human intelligence.
He also repeats his trashing of Sir Cyril Burt, the eminent British educational psychologist, who reported a heritability for IQ of 77 per cent for identical twins reared apart. After his death in 1971, Burt was widely accused of fabricating his data. However, five separate studies of identical twins raised apart have now corroborated his findings. Two meticulously researched books, by Robert B. Joynson and Ronald Fletcher, have vindicated Burt, describing how he was railroaded by anti-hereditarian zealots. Gould ignores them.
Gould`s most inflammatory allegation is to blame IQ testers for increasing the toll of the Holocaust. His thesis is that early IQ testers claimed Jews as a group scored low on their tests. This finding was then allegedly used to support passage of the restrictive Immigration Act of 1924, under which Jewish refugees were denied entry in the 1930s. Gould even claims that Henry H. Goddard in 1917 and Carl C. Brigham in 1923 labeled four-fifths of Jewish immigrants as "feeble-minded . . . morons."
In both cases, this has repeatedly been shown to be untrue. For example, Goddard was testing to see if the standard Binet test identified what were then called "high-grade defectives" as well among immigrants as it did among native-born Americans. (It did.) He explicitly did not assert that 80 per cent of Russians, Jews, or any immigrant group in general were feeble-minded.
Gould repeats his account despite widely disseminated refutations. Historian of psychology Franz Samelson began setting the record straight in the journal Social Forces as early as 1975. Mark Snyderman and the late Richard Herrnstein, writing in The American Psychologistin 1983, corroborated Samelson`s conclusions and showed that the testing community in general did not view its findings as favoring immigration restriction, and that Congress took virtually no notice of intelligence testing in framing the legislation.
The eminent historian Carl N. Degler, in his 1991 book In Search of Human Nature, took Gould to task for ignoring contradictory information. He points out, for example, that the high scores of Orientals did not prevent them from being excluded from immigrating—and that their scores would have embarrassed any attempt to make IQ the basis of immigration policy. Daniel Seligman debunked Gould`s anti-testing propaganda in his book A Question of Intelligence.Herrnstein and Charles Murray, in their book, The Bell Curve, also highlighted the issue in a special boxed section. Gould reviewed The Bell Curve (twice!). Yet he ignores all these counter-arguments in his"revision."
Indeed, in his account of The Bell Curve, Gould charges Herrnstein and Murray with "disingenuousness." He then withholds from readers the fact that their book was principally an empirical analysis of social stratification drawn from the 12-year National Longitudinal Survey of Youth. Most high-IQ 17-year-olds, blacks as well as whites, went on to occupational success in their late twenties and early thirties. Many of those with low IQs, both black and white, went on to welfare dependency. Thus IQ tests are predictive.
Gould`s attack on The Bell Curve focuses on its use of the "general factor of intelligence," or g, which psychometricians hypothesize underlies tests of mental ability. Gould likes to leave his readers chanting the mantra, "g is nothing more than an artifact of the mathematical procedure used to calculate it." But every major study shows that different IQ tests tend to be significantly intercorrelated, suggesting an underlying commonality. Thus Nathan Brody, Arthur Jensen, and John Carroll have all provided detailed empirical and analytical demonstrations of the reality of g (including, incidentally, a strong correlation with brain size). Gould ignores them all.
Gould employs another technical trick as well as attacking g: he continues to argue that findings about IQ differences within groups cannot be applied to differences between groups. (Curiously, he does not object when environmentalists use nutrition as an explanation of both within-group and between-group differences.) Research has found that racial differences are more pronounced on subtests that are highly heritable than on less heritable tests. This clearly supports the genetic hypothesis. Gould ignores it.
And most transracial adoption studies provide evidence for the heritability of racial differences in IQ. For instance, Korean and Vietnamese children adopted into white American and white Belgian homes were examined by E. A. Clark and J. Hanisee, by M. Frydman and R. Lynn, and by M. Winck et al. Many had been hospitalized for malnutrition. But they went on to develop IQs ten or more points higher than their adoptive national norms.
Gould does refer to adoption studies—but only to a German finding of"no difference" between pre-puberty mixed-race children fathered by black soldiers and those fathered by white soldiers. He also mentions a similar result in Minnesota which seems to refer to an early report of the famous Minnesota Transracial Adoption Study. That study has subsequently found, however, that marked black/white differences emerged by age 17. (Environmental influences typically wash out by adolescence.)
FINALLY, Gould continues to ridicule the "ape in some of us"hypothesis proposed by Cesare Lombroso (1836-1909), the founder of criminology. Lombroso argued that many criminals were throwbacks to man`s ancestral past, and that "natural-born criminals" could be identified by anatomical signs of primitiveness. (Contrary to Gould, however, Lombroso also believed that criminal behavior could arise in"normal" men.)
The reader of Mismeasure will search in vain, however, for even a dismissive reference to recent evidence that criminal behavior does indeed have a biological basis. Adrian Raine has reviewed several studies using MRI, Computerized Tomography, and Positron Emission Tomography to inspect the brains of violent and sexual offenders. He tentatively concluded that frontal-lobe dysfunction was associated with violent behavior, including rape. Further, it has been long established that criminals tend to have lower IQs than non-criminals. So, given the relation between brain size and IQ, Lombroso`s finding of a smaller brain in criminals is probably correct.
Nor does Gould feel compelled to let his readers know that Lombroso`s ideas have now received considerable support from behavioral genetics. Studies reported by Raine, David Rowe, and myself show that criminality is substantially more likely to be shared by identical twins than by fraternal twins. This clearly suggests a genetic factor, since both sets of twins share environments, but only identical twins have identical genes. Similarly, American, Danish, and Swedish studies of children adopted in infancy show that adopted children were more likely to be criminals if their biological parents—rather than their adoptive parents—were also criminals.
Even Lombroso`s theory of bodily markers is not as far out as Gould would have you believe. It is now understood that drugs in pregnancy or other "insults" to the fetus may disturb its brain development and simultaneously produce a minor physical anomaly (MPA). For example, fetal ears start low on the neck and gradually drift upward. An insult to development can stop this and result in low-set ears—an observable MPA. Thus, the number of MPAs is a rough index of (perhaps hidden) central-nervous-system anomalies.
For children raised in unstable families, Raine found that the number of MPAs at age 12 was related to violent behaviors at age 21. More generally, Raine even found that antisocial children often had more facial deformities, as judged by expert plastic surgeons.
In suppressing the hypothesis that genetics matter in crime by sneering at the long-dead Lombroso and ignoring the latest research, Gould is actively obstructing scientists from finding ways to spare both future victims and delinquents—who, in their own fashion, are also victims. It is thus Gould who is—in Lombroso`s words—the delinquent man.
Gould tells us 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." He 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. This has become the apostle`s creed of the adversary culture. However, even the most deeply held views cannot justify withholding evidence, engaging in character assassination, and repeating unfounded charges despite refutations.
"May I end up next to Judas Iscariot, Brutus, and Cassius in the devil`s mouth at the center of hell if I ever fail to present my most honest assessment and best judgment of evidence for empirical truth," swears Gould on page 39 of his new introduction. By his own standard, Gould has consigned himself to the innermost circle of hell. But science, fortunately, is neither religion nor politics. Gould can save himself by owning up to the facts and ending his career of relentless special pleading.
J. Philippe Rushton [email him] is a professor of psychology at the University of Western Ontario, the author of Race, Evolution, and Behavior. This essay is based on his recent articles published in Intelligence,January 2007 (PDF), and Proceedings of the Royal Society of London, July 2007 (PDF).