Steven Pinker tackles sexual differences in Sex Ed:
The fact that women make up only 20 percent of the workforce in science, engineering, and technology development has at least three possible (and not mutually exclusive) explanations. One is the persistence of discrimination, discouragement, and other barriers. In popular discussions of gender imbalances in the workforce, this is the explanation most mentioned. Although no one can deny that women in science still face these injustices, there are reasons to doubt they are the only explanation. A second possibility is that gender disparities can arise in the absence of discrimination as long as men and women differ, on average, in their mixture of talents, temperaments, and interests — whether this difference is the result of biology, socialization, or an interaction of the two. A third explanation is that child-rearing, still disproportionately shouldered by women, does not easily co-exist with professions that demand Herculean commitments of time. These considerations speak against the reflex of attributing every gender disparity to gender discrimination and call for research aimed at evaluating the explanations.
Some anecdotes:
Anyone who has fled a cluster of men at a party debating the fine points of flat-screen televisions can appreciate that fewer women than men might choose engineering, even in the absence of arbitrary barriers. (As one female social scientist noted in Science Magazine, “Reinventing the curriculum will not make me more interested in learning how my dishwasher works.”)
A summary of the science:
As I noted in The Blank Slate, for instance, men are, on average, better at mental rotation and mathematical word problems; women are better at remembering locations and at mathematical calculation. Women match shapes more quickly, are better at reading faces, are better spellers, retrieve words more fluently, and have a better memory for verbal material. Men take greater risks and place a higher premium on status; women are more solicitous to their children.
One of the more interesting points Pinker brings up in The Blank Slate:
The psychologist Philip Tetlock has argued that the mentality of taboo–the belief that certain ideas are so dangerous that it is sinful even to think them — is not a quirk of Polynesian culture or religious superstition but is ingrained into our moral sense. In 2000, he reported asking university students their opinions of unpopular but defensible proposals, such as allowing people to buy and sell organs or auctioning adoption licenses to the highest-bidding parents. He found that most of his respondents did not even try to refute the proposals but expressed shock and outrage at having been asked to entertain them. They refused to consider positive arguments for the proposals and sought to cleanse themselves by volunteering for campaigns to oppose them. Sound familiar? [...] At some point in the history of the modern women’s movement, the belief that men and women are psychologically indistinguishable became sacred.