I suggest you read this essay. Here is a sample question that explains the male-female dichotomy in science:
"From Geoff B: Perhaps men have a greater buffer of time to recover from career mistakes. I actually know a couple of guys who got PhD's, then went to MBA or JD degrees. While they may have enjoyed their PhD programs (heh), from an earning standpoint they probably wasted a good 5-7 years. But they can just pretend that those 5-7 years never existed. A 40 year old man can get married to a 31-year-old woman, and just pretend he's 31. Happens all the time. It's harder for women to pull this off. So maybe math and science PhD's are just another incarnation of the recklessness of youth - something men have historically been able to indulge in, without the consequences women would experience.
From me (responding to someone who asked how I would change the incentives so that more women would be attracted to science): What's my idea for changing the incentives? I don't have any. I'm not one of the people who complains that there aren't enough women working as professors, janitors, or whatever. For whatever reason we've decided that science in America should be done by low-paid immigrants. They seem to be doing a good job. They are cheap. They are mostly guys, like other immigrant populations. If smart American women choose to go to medical, business, and law school instead of doing science, and have fabulous careers, I certainly am not going to discourage them. Imagine if one of those kind souls that Summers was speaking to had taken Condoleezza Rice aside and told her not to waste time with political science because physics was so much more challenging. Just think how far she might have gone..."