Drops in violence and changes in the kind of violence (yay arrows!) in the past 20 000 years have reduced the need for cognitive back ups as well as robust skulls since brain trauma is less common. Our ancestors may have had bigger brains but not have been much or any smarter because they literally got hit on the head more often.
The survivable brain trauma is a product of our adults play-fighting like kittens. Real violence using stones and sticks got larger variance of damage and fewer of the cases would fall into brain-damaged-survivor range.
Picture seriously huge people, built like athletes, fighting not with gloves on their hands but stones in their hands (and stones on sticks). There won’t be many knock-outs where the knocked out party ever gets up again.
Why didn’t Neanderthals evolve it then? Larger brain volume, but musculature sufficient to make a fist a deadly weapon. They could stave in each other’s skulls with a punch.
Evolution doesn’t work that way. The fact an option is available doesn’t mean they will evolve for it unless there is such strong selection pressure to do so it outweighs other factors.
Hypothesis I just made up:
Drops in violence and changes in the kind of violence (yay arrows!) in the past 20 000 years have reduced the need for cognitive back ups as well as robust skulls since brain trauma is less common. Our ancestors may have had bigger brains but not have been much or any smarter because they literally got hit on the head more often.
The survivable brain trauma is a product of our adults play-fighting like kittens. Real violence using stones and sticks got larger variance of damage and fewer of the cases would fall into brain-damaged-survivor range.
Picture seriously huge people, built like athletes, fighting not with gloves on their hands but stones in their hands (and stones on sticks). There won’t be many knock-outs where the knocked out party ever gets up again.
Why didn’t Neanderthals evolve it then? Larger brain volume, but musculature sufficient to make a fist a deadly weapon. They could stave in each other’s skulls with a punch.
Evolution doesn’t work that way. The fact an option is available doesn’t mean they will evolve for it unless there is such strong selection pressure to do so it outweighs other factors.