I echo Kathy G in urging you all to read Echidne of the Snakes coomenting on a recent Boston Globe story which suggests that women may be 'self-selecting' themselves out of hard sciences. Let me excerpt the part where Echidne compares the framing of women's underrepresentation in the sciences with that of men's underrepresentation in US colleges and universities.
To see what stinks in all this, let us take a step backwards, away from this particular article and into the wider field of science politics about gender. All comfortable now? Sit back and notice that the debate about women and numbers has its rough mirror image: the debate about boys' trouble at school. Do you notice anything different in those two big stories? Do you happen to notice, say, that we never read someone writing that maybe boys just self-select away from education? Maybe they are not just interested in staying at school or in going to college? I don't recall ever reading a single article like that. Nope, all the articles I've read about the topic have as their goal a greater success rate for boys. Boys must be educated! Nobody suggests that they might choose not be educated and that we should honor that free and democratic choice.
But when it comes to girls and science, the story immediately changes. Perhaps it's girls themselves who choose not to become scientists? Perhaps that's Just How Things Are?
The two big stories have other odd differences: The stories about boys-and-schools are mostly about what is wrong with schools that makes boys less than thrive. The stories about girls-and-science are more complicated, often focusing on what is wrong with girls rather than with the culture of science. Or that nothing is wrong at all, because girls just don't want to do science.
There is a lot more there, so go read the whole thing.
Here's another example of what Echidne's talking about.