Most women do not want a career in STEM and nor do most men. Why should the small fraction of women who <i>do</i> want such a career be the same size… - Steve Stewart-Williams

Just as our tools evolved culturally to fit our hands, so too our social roles evolved culturally to fit persisting aspects of the human mind. Roles that jar too violently with human nature are unlikely to persist for long, at least without the application of significant social force. If this is correct, it raises the possibility that some social roles might have evolved culturally to fit traits that, although found in both sexes, are more common in one than the other. This is emphatically not to say that there are some male roles and some female roles. But it is to suggest that there might be some social roles that suit more men than women, and others that suit more women than men — not just because of evolved physical differences but because of evolved psychological differences as well.

The idea that humans form pair bonds, and that males often invest in their young, has a long history in biological anthropology. Early incarnations of the idea were criticized for painting an overly simplistic picture, according to which “Man the Hunter” provisioned his dependent wife and children with meat in a stable nuclear family, suspiciously reminiscent of a 1950s-style Western family. However, with appropriate amendments and qualifications, the idea that pair bonding and biparental care are a central part of our evolutionary endowment appears to be viable.

This is especially important when addressing less statistically savvy audiences. Such audiences could perhaps be encouraged to think of two normal distributions, one representing males and the other females. Instead of imagining that natural selection creates two distinct psychological types — a male type and a female type, described by the mean values for each group — they could be encouraged to imagine that natural selection pushes the male and female distributions closer together or further apart. This simple expedient may help people to visualize the effects of natural selection on average sex differences without at the same time losing sight of the variation within each sex.