[Jtsummers]

A large part of this is culture. My ex-girlfriend grew up with parents who coddled her and her sister, protecting them from many things (a common behavior with female children from what I've seen). The consequence is two very fearful women (nominally) who have strong aversions to technical fields. They were told it was ok they weren't good at math because they were girls.

On the other hand, I've worked with and known many women in adult life, and either they overcame that attitude from their parents and teachers or they weren't presented with that attitude growing up. I can speak with many of them about programming topics (watered down in the same manner I'd water it down with men who don't have a programming background) and bore or interest them to the same degree.

If we, as a society, stop telling people "this is feminine" and "this is masculine" (particularly with respect to fields of study, both technical and non-technical) you'd likely see these things even out quite a bit (though the implied feminine and masculine by observing people's roles in society will still be present).