[irdc]

Self-domestication. That in order to be more successful as a collective species we had to literally breed ourselves to become less violent and more playful and sociable.

And the nice part is that it wasn't just one person deciding this but the collective intellectual leap of all those people throughout our history who decided to reproduce with the less violent and more cooperative members of the opposite sex.

And it must have been intellectual, because on the animal level being more capable of violence is surely an individual advantage.

[cjbgkagh]

I think it was more the violent people were hung, or ostracized to die in the wilderness. Animals likely have similar genetic pressures as some animals have evolved ways to determine who’s the strongest with contests instead of the more deadly violence that they care capable of.

[accidentallfact]

That, just isn't true. Many animals live in herds, flocks or other groups. There is a kind of fish that eats debris from the teeth of much bigger fishes. Predators get swarmed.