Re: Not just IT
I'm pretty sure it's mostly "C" coupled with a corresponding amount of "A". I've seen countless times in life that people always end up playing to their strengths - relying on them, developing behaviour with those at the center; one of the most striking such patterns is that people not needing to do things for themselves just never learn to do them - it's just much easier to rely on one's ability to get other people do it for them. And before anyone objects, I've seen this applied by men just as well as by women - although admittedly male instincts toward women are an easily exploited target and form the bulk of such behaviour. If people like you, they tend to offer their help, and you tend to grow up learning to rely on that - as simple as that.
The other side of the coin is that this is just a generalization - specific individuals, male or female, will learn whatever they are interested in: I have seen women in IT that couldn't have been kept out of it even by sharks with lasers. But they are the exception; a lot of women actually just don't seem to enjoy the sort of challenges IT tends to offer so they stay out of it - if you want proof just stroll up to someone and try explaining to them the last problem you faced and how you solved it (if sixty seconds later she's still around you, you're either looking at a unicorn or she really likes you). Like it or not, that's not going to be less true just because someone has a chip on his shoulder and some windmills to fight...