A post in
damnportlanders reminded me of a pet theory of mine:
Back when we were swinging from trees, there were four possible gender combinations: aggressive males/aggressive females, passive males/passive females, passive males/aggressive females, and aggressive males/passive females.
Any combination in which the females were aggressive - by which I mean participants in activities like hunting and fighting with rivals - would have endangered their young. Since most large primates have low fecundity and their offspring take several years to reach adulthood, this would have put populations with aggressive females at a significant evolutionary disadvantage. Groups where both sexes were passive would have been wiped out even faster. Strong, aggressive males and passive, nurturing females would have been the optimal combination for survival. This was probably very strongly selected for. And it continued to be strongly selected for long after we became human. It wasn't until the rise of advanced civilizations that any other combination was even possible. And thousands of years is just the blink of an eye in evolutionary time...