Freakonomics had an interesting study as a part of their… whatever you want to call it. Basically, in misogynistic cultures women are simply raised not to take risks while men are encouraged to.
I think it makes sense, and I remember a really nice statement from Meg Whitman about the way she’s seen women position themselves in business showing a lack of confidence in their position by subtle touches; more specifically I remember her sharing a story about women in a lunch meeting lining the outside of the conference room and not eating as every man in the room ate at the table during the meeting, and how that segregation speaks to attitudes that need to (and are) changing.