Eileen Pollack has a very long article in the New York Times that goes in-depth on the issue of why there are so few women in science. It’s a great, comprehensive overview of the subject with references to pretty much all the major studies that have recently come out about the issue. I won’t try to summarize it, but if you’re at all interested in the subject (I am), you should read this article.
Also: you should be interested in this subject.