Then why is it, that it is almost exclusively boys who play RPGs in that age range? Do the girls get discouraged by the boys' behaviour in-game? Is it because D&D (the 30-pound gorilla of the RPG market) is so aimed at the juvenile power trip that has spiralled out of control?
I know, I'm not the first one to wonder about this, but I haven't read the answers anywhere. Maybe I should ask my female RPG-friends how and when they got into RPGs in the first place. I'm convinced that, given a mature enough GM, a small group of mixed gender could come to enjoy RPGs.