Both, probably. However, it's not unlikely that biological changes as a result of hormones wouldn't have any effect on the human brain.
WIKIDUMPOh, and wherether they are caused by nature or nurture, the differences are there and won't go away by ignoring them.
I have gay friends that would contest any "men aren't complicated" claim quite aggressively.
@ebbor: I don't see why statistic/"brain scan" methods rule out the possibility of learned behavior.
When did I say that? I just stated that the average male (group) has a tendency to speak less, form leader structures easier and is better at abstract reasoning.
Because male and women in similair situations/ upbringin/jobs still show significant changes* in brain structuring and usage when asked different type of questions.
Link *We're talking about things like language and such being handled by entirely different parts of the human brain, and such.
Isn't there something like a 70% difference in the amount of connections between the left and right hemispheres of the brain for men and women? I forget which way round it is but I'm pretty sure that it's a thing.
Unaware of that. What I do now is that the connections made are different. For example, females activate both hemispheres for language, rather than just the left. (or was it right, can't remember)
Other things are that the male brain is significantly heavier/larger, but also less efficient with connections.