I think the answer is the same reason the male brain is larger than the female brain on average. The part of the brain that handles fighting. It's a pretty la

I think the answer is the same reason the male brain is larger than the female brain on average. The part of the brain that handles fighting. It's a pretty large part of our brains. The reptilian hindbrain that handles violence isn't needed nearly as much now that we have society and civilization. It's shrinking.