Whether or not there is a difference in biology, most likely there is something much more overt that swamps that difference.

Girls get the message early on that their abilities are unwanted in areas that have traditionally been the province of boys. A bit later many get the message that they are appreciated for the sexual opportunity they represent and their abilities are minimized.

I've read too many stories of women who faced this in STEM subjects, and it is apparently even worse in the gaming community.