People (Americans in particular) want to discount genetics, pretend that we can all be anything we want to be, that we have no inbuilt limitations.
Of course we know that is false. Most simply it can be seen (and strangely the one area it is accepted) is athletics. Some people have the genes that allows them to become top athletes, the rest don't and that is that. We also see in athletics the difference between men and women, that the genders are not equal at the top, they have areas they are better in.
Well, this carries over to mental, emotional, and other differences as well. Your genetics don't dictate who you are, but they do define some limits on you and also what you might be interested in.
So you are going to see differences in the interest of the genders, even without any societal forces. One interesting example I see is veterinary medicine. Since it has become a field that was acceptable for women to work in (used to be teaching and nursing was all that was considered "ok" for women to be in) it has become very popular for women. The vet office I use is ALL female. All the vets, all the vet techs, all the receptionists, all women. From what I've learned, the heavy amount of women is not an anomaly, it is a field that women have a lot of interest in.
Now why is that? I'm not sure, I've never seen any research on it. Perhaps it is the nurturing aspect that appeals to many women. Whatever the case it certainly isn't something where there's a big push in society to "get women in to veterinary medicine" yet it is happening. It appeals to women, so they go in to it.
None of this is to say that culture and childhood encouragement don't play a part, of course. If a girl is interested in computers but continually told that "girls don't play with computers" that can well change the course of her life. However we have to be open to the idea that just as different individuals have different predispositions, so do the sexes.
We may always see a situation where there are less women interested in IT than men. Frankly I don't think that should be a concern, so long as we make sure it isn't because women are being unfairly forced away from it. I would think it far worse to try and start pressuring women in to careers they don't like all with some misguided idea of "balance".
I guess I feel pretty strongly about this because computers were something I always wanted to do, since as long as I can remember. This wasn't because of my family, mom, dad, grandparents, none of them are technically savvy. However I loved computers and electronics and was fascinated by it from age 3. Clearly it is just one of those things about me, a genetic predisposition. I'm glad I got to follow that, and I wasn't told to do something different because people decided that I should have interests other than that.