The recent suggestion by Larry Summers, Harvard University president, that one of the factors contributing to the lower representation of women in the sciences might be innate differences between the sexes has unleashed the predictable fury from feminists and their fellow ideologues. The responses to Summers indicate once again how little respect many in academia really have for the principles of academic freedom and rational discussion. Even had he been mistaken, the reaction should have been more moderate, but as it happens he was not.
Men and women do differ in their intellectual talents, and if by "innate" we mean influenced or determined before birth, then some of these differences are indeed innate. Differentiation between the sexes depends heavily on the difference between them in levels of sex hormones early in prenatal life. These hormone levels determine not only the physical diferences, but also strongly influence many behaviours into adulthood. Those behaviours include the intellectual or cognitive pattern, hormonal influences being especially well documented for certain kinds of spatial ability, like being able to mentally rotate or manipulate visual objects.
Men are, on average, better on such spatial asks and on mathematical reasoning tasks than are women. Women, in contrast are better, on average, on tasks requiring verbal memory (recalling word material), and also in recalling the position of objects presented in an array. There are many other less striking differences.
Mathematical reasoning ability is especially important for physical sciences like physics and engineering, and since many more men than women score at the high end of math aptitude tests, it is reasonable to expect that more men will go into those professions. Note that boys and girls may not differ in their grades on math tests in school, but the same boys still excel on math aptitude tests, where the items are less rehearsed.
Spatial ability is also highly related to professional choices. Even when verbal intelligence is equal, those people with higher spatial and math ability (more of them men) gravitate towards the sciences, rather than law or medicine. Women are much more likely to choose and thrive in biological sciences than physical sciences, suggesting that general explanations like a "chilly climate" in the sciences are untenable. The appeal for women may be related to the fact that biology deals more with living things.
These are reliable findings that have been widely available in both scientific journals and popular media for several decades now, and many of the important researchers in this field are women. It is therefore ludicrous for MIT biologist Nancy Hopkins to claim that she was so shocked by Summers' remarks that she had to leave the meeting in order not to faint or throw up! What message about women’s capacity to engage in dispassionate discussion does this send?
Other well-documented relevant factors that differ between men and women include the preference by women to choose more person-oriented occupations, rather than object-oriented fields. This holds even for women highly talented in math, who have entered math-intensive programmes and have had strong encouragement to continue in related fields. Another important factor in determining fields of advanced study for women is the preference for non-lab or less intensive research activities, where they can indulge the natural tendency to spend more time with their children. This is a legitimate choice with intrinsic rewards, but one should not then expect equal professional rewards.
That said, nothing in the findings on sex differences should be interpreted to mean that women (or men) should be discriminated against in any field except on the basis of individual ability and performance. Although the average differences between men and women on some abilities may be quite large, there is always substantial overlap between the sexes. We should clearly allow individuals to pursue their own talents and interests, and women who excel in the physical sciences and math will succeed. BUT it is to be expected that there will be a different representation of men and women across many occupations, as people self-select themselves into jobs based on such talents and interests.
Lest some people think that women still suffer discrimination in hiring in academia, the research, in Canada at least, shows just the opposite. Several studies have shown that women are favoured over men in university faculty hiring, including my own survey of hiring at two major British Columbia universities. Women's groups have been sadly effective at crying victim, to the point where men have become disadvantaged.
Dr. Summers has now disappointed all serious academics by his subsequent apology and retraction, bowing to pressures originating, not from thoughtful critiques of his remarks, but from hysterical reactions of special interest groups. His response is mirrored in too many university and research grant administrations, where the tired refrain is that women still suffer “serious obstacles”, at best only vaguely defined, to success in science.