Judge Richard Posner has stepped into the tedious debate over innate cognitive differences between men and women. While I’m usually a fan of Posner’s contrarian streak, he indulges here in some terrible evolutionary psychology. He manages to justify a blatant inequality – women have lower average earnings than men – by constructing a silly, trite and untestable hypothesis about our “ancestral human environment”:
the mean performance of women in college and university is superior to that of the men, but the variance of male performance is greater and as a result there are more male geniuses. There is no reason why the difference in variance should result in higher average male earnings; that higher average is probably the result of women’s spending less time in the work force because of pregnancy and child care. Women’s greater proclivity for child care may well have a biological basis, as may the difference in variance that I mentioned. In the “ancestral environment”–the term that anthropologists use to describe the prehistoric period in which human beings reached approximately their current biological state–women who were “steady” would have tended to have the maximum number of children, while natural selection might favor variance in male abilities because variance would produce some outstanding men who would tend to reproduce more than other men (including the “steadies”) in the polygamous conditions of prehistoric society. If the explanation based on evolutionary biology is correct, women will continue to be “underrepresented” in high-achievement positions in many fields; why anyone should care is beyond me.
So we’re not supposed to care about female inequality because natural selection favored “steady” women several hundred thousand years ago? This is the pernicious danger of bad evolutionary psychology. By purporting to discover our evolved essence, evolutionary psychology in a sense justifies whatever that essence is. After all, it’s futile to resist the urges of biology, even if it leads to unfair treatment in the workplace.