A few years back I designed a better evolutionary ancestral environment for homo sapiens. It’s on an island of moderate size, where you can grow all kinds of stuff, but only on a small percentage of the area maybe 1% that is spread out over the entire island. In the rest of the ground only a kind of tuber growth which is very nutritious and doesn’t require any cultivation, but it has a small side effect: it’s a very strong contraceptive.
The idea is this setup prevents any kind of Malthusian trap. When is the population grows too much a growing number of people has to eat the tuber to get by. And because those people don’t have any children the population in turn starts declining in an entirely nonviolent fashion. Because the tuber is always available there is no famine, women are not dependent on a man for their children to survive. So they have no reason to evolve to be quite as crazy.
Because the normal diet contains the strong contraceptive, women don’t have to be very choosy with their partners because they will only bear children when they consciously stop eating the tuber. Because there is no overpopulation and women are not particularly choosy, men evolve to be less violent and boisterous. Because you don’t only have to get into a woman’s pants to procreate, but you actually have to convince her to want to have children with you, men evolve to be more supportive and stable partners.
Well, that was the idea anyway. I am absolutely sure evolution would find a way to fuck this up.