Women might also be filtered out by gatekeepers: teachers, advisers, interviewers and admissions committees. In an earlier thread, I quoted a physicist who wrote about this:
http://news.ycombinator.com/item?id=625431(Not to mention peer pressures; it can be hard to fit in socially with your peers when you're different. For example, many hackers have complained about the abuses they suffered during highschool.)
In the _Princeton Companion to Mathematics_ (which I very much recommend for anyone interested in math), mathematician Dusa McDuff claimed:
> Very successful within this limited sphere, I was highly motivated to be a research mathematician. While in some respects I had enormous self-confidence, in other ways I grew to feel very inadequate. One basic problem was that somehow I had absorbed the message that women are second rate as far as professional life is concerned and are therefore to be ignored. I had no female friends and did not really value my kind of intelligence, thinking it boring and practical (female), and not truly creative (male). There were many ways of saying this: women keep the home fires burning while men go out into the world, women are muses not poets, women do not have the true soul needed to be a mathematician, etc. And there still are many ways of saying this. Recently an amusing letter circulated among my feminist friends: it listed various common and contradictory prejudices in different scientific fields, the message being that women are perceived to be incapable of whatever is most valued.
As a programmer, I'm very interested in meetings without common negative patriarchal traits, like ego. She claims:
> I have found meetings intended primarily for women to be unexpectedly worthwhile; the atmosphere is different when a lecture room is full of women discussing mathematics. Also, as is increasingly understood, the real question is how any young person can build a satisfying personal life while still managing to be a creative mathematician.