In response to:

A Simple Problem Science Can't Solve from the April 12, 1984 issue

To the Editors:

Professor R.C. Lewontin is clearly sympathetic to feminist concerns. In his review of Vivian Gornick’s book Women in Science: Portraits from a World in Transition [NYR, April 12, 1984), he challenges Ms. Gornick’s view that all is well for women in the world of science. As a springboard for his discussion, Lewontin references Plato and his Academy. For Plato, woman’s nature is “qualitatively the same as men’s” but women as a group “possess these qualities in lower degree on the average,” although the differences could be eradicated with egalitarian education. For Lewontin, the problem for women “is not a lack of merit, but a lack of power” that is jealously withheld from them. Yet Lewontin was taken to task, unfairly I think, for allegedly misrepresenting Plato’s egalitarian views and for being biased himself (R.J. Nelson, NYR, October 25, 1984; Martha Nussbaum, NYR, January 31, 1985).

According to Lewontin, “the problem for women in science is the problem for women everywhere, that their selves are denied value.” He suggests that women may be doing science and loving it, but science is as much a way of life to attain self-esteem and personal freedom as it is an intellectual pursuit with wonderful moments of scientific discovery. The Barbara McClintock-type of unencumbered intellectual paradise may not be as wonderful as it appears if being “freed” from departmental responsibilities and politics in fact amounts to being excluded from potentially self-fulfilling activities and associated benefits. For Lewontin, not to recognize women’s difficulty in achieving respect, self-esteem and power in academia is to miss the feminist argument.

However, Lewontin’s zeal in promoting equality has led him to exclude the possibility that there may be natural differences in aptitudes and motivation between men and women and that biological as well as environmental factors may cause the societal sex differences. In fact, the possible role of sex differences in the brain and cognition was completely dismissed in the Lewontin, Nussbaum and Nelson interchange. Professor Nussbaum states that in a society with Plato’s proposed equal education, the “remaining differences in physical function” between the sexes would not be a hindrance to women. No sexual dimorphism is considered for the brain, only for the gonads. Nussbaum simply does not keep the brain in mind. She implores academics “to look searchingly and self-critically into his or her own heart.” Lewontin describes the scenario that “genes make hormones and hormones influence neural development and neural development makes professors,” but states that this is irrelevant for the sex differences in society.

But how does he know this? Extensive documentation now exists that the sexes differ in brain structure and function. For example: the male canary sings, the female does not. Their behavior is different and so are their brains. With manipulation of sex hormones, the female becomes male-like: she sings and her brain develops male morphology. 1 Enriched environment, well documented to result in improved learning ability, has been demonstrated to result in greater neural dendritic growth in male than in female rats. This is a clear indication of the interaction between nature and nurture.2 But it is the female rat that shows greater neuronal regrowth following brain damage.3 Sexual dimorphism in brain structure and function is indisputable in many species, including humans. Even the uniquely human function of speech and language appears to have a different neural substrate in the sexes.4

Within this framework of discoveries in psychobiology, Lewontin dismisses the possibility of neurobiological and consequent cognitive differences between the sexes. He criticizes scientists Benbow and Stanley,5 as well as the journal reviewers and editors, for publishing a paper which reported sex differences in mathematics performance and which postulated biological as well as environmental variables as possible determinants of the difference. Benbow and Stanley observed that in ten different surveys involving 9927 intellectually gifted Grade 7 and 8 students, not once was the highest score achieved by a girl. Moreover, 11.1 percent of 5674 boys scored higher than 600 (a score already well above average), whereas only 1.7 percent of 4253 girls did. Further studies have corroborated these findings.6 The authors did not simplistically conclude that environment is irrelevant and that females lack “math genes”; they hypothesized that the superior male performance in mathematics which is present in childhood may be a result of “both endogenous and exogenous variables.” In view of current neurobiological findings, such results certainly warrant the hypothesis of the operation of some natural factor.

For Lewontin, the essential nature of sex differences in academia is one of social power. Again, how does he know this? This too is an hypothesis, and even if true, could be due to antecedents, such as differences in natural abilities, motivation or commitment. To have power, like riches and lovers, one has to want it, work for it and strive to maintain it. To do so involves mental functioning and mental functioning depends on brain functioning. Perhaps women strive less for power because it is less reinforcing for them for biological reasons. Political power has been suggested as serving different functions for men and women.7 What were the priorities of Gornick’s Cornell University assistant professor “Patty” who chose to marry and leave her job compared to those of her husband who chose to marry and move to his job? Perhaps she would not have been chided by her boss in mid career for being overly ambitious had she been sufficiently ambitious earlier to refuse a nonadvancing position. It seems unlikely to me that society could be so remarkably successful in teaching a large majority of women to shun power, to achieve only so far in mathematics, and yet prove so ineffective in achieving other broadly accepted moral and educational aims.


It would be unwise to prematurely and uncritically accept biological factors as a determinant of the sex differences in our society. But it would be equally unwise to reject or suppress the consideration of such a possibility, as in the suggestions that such hypotheses are untimely, politically motivated or “a sorry artifact of another scientific age.”8 The possibility of biological determinants of sex differences warrants empirical testing. The more readily accepted environmental hypotheses also require empirical validation. The documentation of either factor does not preclude the consideration of the other. And what if natural differences are found to be partly responsible for sex differences in behavior? A physical basis of thought does imply scientific determinism of behavior. Unfortunately this position is unpalatable to many because it is mistakenly thought to deprive humans of free will. But free will is fully compatible with the operation of natural laws in brain functioning.9 Furthermore, equal opportunity is not based on equality. Natural variation is recognized within each sex; no environment can make everyone a Mozart or a Marie Curie. No matter what factors emerge, responsible action still requires individual consideration for each man and woman.

S.F. Witelson
McMaster University
Hamilton, Ontario

R.C Lewontin replies:

Professor Witelson’s letter follows the canonical form for the biologistic view of human social and individual differences. The elements of that form are:

1) The suggestion that in view of our ignorance, we ought not “exclude the possibility that there may be natural [biological] differences in aptitudes and motivations.” Who could argue with the call for an open mind? The problem is that beyond the repeated assertion that there may be an anatomico-physiological basis for differences in status, wealth, and power, biological determinists have never found any credible concrete basis for such differences. For all I know, we are being visited daily by extraterrestrial creatures. There is certainly nothing in the laws of physics to prevent it. But I really do require more than out-of-focus snapshots to make me take the possibility seriously.

2) The citation of evidence from animals as corroboration. After all, people are animals, aren’t they? Yes, indeed, and they have certain properties in common with other animals, like being made of cells. But the further one gets from the immediate properties of cells, the greater the diversity of causal pattern among species. Behavior that is hard-wired and stereotyped in one species may be utterly plastic in another. More important, behaviors that are casually equated in different species may not be the same thing at all. Who says canaries “sing”? They certainly make a high-pitched vocalization, but anyone who confuses canaries twittering with the performances of the “Swedish Nightingale” just hasn’t thought much about human society. All other vertebrates, including primates, have sex in seasons, and in stereotyped forms. Only human beings copulate at all times of year, at every hour of the day and night, underwater, in balloons, and in every possible three dimensional configuration. To understand human beings, I am afraid there is no substitute for understanding Homo sapiens.

3) The claim that consistent differences must be, by their very consistency, biological. Despite Benbow and Stanley’s explicit claim, apparently approved of by Professor Witelson, that the very size of the test differences between males and females is evidence of biological causes, there is, in fact, no rule of biology that allows one to infer anything about causation from the size of a statistical or individual difference. It is simply a non sequitur. Does the shortage of Jews among the heads of the Fortune 500 corporations reveal a biological inability to make big money? Perhaps it is just that their genes predispose them for finance rather than industrial capital. Of course, it might be argued that Benbow and Stanley are dealing with objective tests and not social achievement. The notion that tests marked by machine must measure something intrinsic is another delusion of biological determinism.

4) The claim that the most up-to-date scientific knowledge has finally uncovered the anatomical difference that separates them from us. In the nineteenth century, it was thought that the ovaries compete with the brain for developmental energy. That turned out to be rubbish. Then it was claimed that women’s brains were smaller than men’s. That is true, but not when corrected for body weight and, anyway, brain size in humans has no correlation with mental ability. The latest fad is brain lateralization. Different functions are concentrated in different halves of the brain, and men are supposed to be more lateralized, that is, more asymmetrical, than women. Unfortunately, this theory leads to certain contradictions which are handled by an ad hoc rationalization that ought to embarrass even the most devotedly biologistic. Professor Witelson herself has given us, as reported in the pages of Psychology Today, a paradigmatic example of double-think about the split brain:


For example, men are superior on tests of spatial skills and tend to show greater lateralization of spatial function to the right hemisphere. Here, greater lateralization seems correlated with greater ability. However, in the case of languages, women, in general, are superior to men, who show greater lateralization of language skills to the left hemisphere. Thus, with languages, greater lateralization may be correlated with less ability.*

Left I win, right you lose.

5) The suggestion that those who do not find biologism compelling are just unwilling to face the unpleasant facts of an “unpalatable” position. Sensible people swallow and digest even unpalatable facts, like the fact of their inevitable demise. What does not go down so easily is rotten logic and bad evidence.

Professor Witelson makes the unpalatability argument at her peril. I might argue, ad mulierem, that a full professor at a first-class university must find it a great deal more palatable to think of herself as a truly superior and exceptional woman than to face the possibility that she is simply a lucky fish who has wriggled through a hole in the net meant to contain her.

This Issue

October 24, 1985