> a lack of diversity certainly signals that something is going on.
Various things can cause gender imbalance. For example, more men than women are colorblind, but the numbers themselves should not be enough to call those colorblind men sexist, reasoning that if women are underrepresented in this group, there certainly must be some sexism that drives them away.
Even if you would compile a list of sexist quotes by colorblind men, or a list of stories by colorblind women how they faced sexism in their life, it still would not be a proof that the greater numbers of colorblind men are caused by sexism.
If we accept this reasoning for color blindness, why not e.g. for autism? It seems like many IT guys are (some of them more, some of them less) somewhat inside the autistic spectrum. Spending your childhood playing with toys, as opposed to social activities with other people, seems like something that half-autists would do, and also like something that can contribute a lot to being good at IT stuff.
> A while ago i read a very thought-provoking book entitled "Unlocking the Clubhouse"
I am going to read this book, to see the other side of the story. But that will take some time. Meanwhile, I looked at some reviews of the book.
The reviews mention stuff like "male CS students are obsessed with computers from early childhood", "boys form friendships around computers and teach each other", "girls see their fathers more interested in computers than their mothers", "boys spend more time playing computer games" -- which is coincidentally also what we would expect to see if there was a statistical biological difference between the sexes. (I am not saying this proves the difference, only that it does not disprove it.) They mention that women that dropped out of CS said that they were "not that much interested in programming", but of course the authors of the book know better, and those poor girls simply don't understand themselves. The recommendations for schools to keep more women in CS include stuff like not focusing on CS too much.
I will give this book a chance, but I suspect it will turn out to be only convincing for those people who are already convinced.