I think the fact that we can organize billion souls under the flag of a nation state speaks volumes enough.
Did neanderthals have this capacity? I don't know. But if their psychology did not facilitate large scale collaboration, a violent human tribe killing a bunch of them now and again would explain some part why they disappeared.
I'm not saying a human tribe hunted them - just that a violent human tribe would attack all hominids around them.
And if the Neanderthals did not have this capacity for mass violence, in time these conflicts would dwindle their numbers.
It's not enough to be more aggressive. You have to be more aggressive in larger, more coordinated groups. The greatest warrior in history couldn't fight off an army on his own.
It's very difficult (read:impossible) to get evidence for something like this because there is essentially zero detail on these ancient societies. However, it's a theory that is consistent with anthropology, sociology, and evolutionary biology. Could be totally wrong, but probably not.
Did neanderthals have this capacity? I don't know. But if their psychology did not facilitate large scale collaboration, a violent human tribe killing a bunch of them now and again would explain some part why they disappeared.
I'm not saying a human tribe hunted them - just that a violent human tribe would attack all hominids around them.
And if the Neanderthals did not have this capacity for mass violence, in time these conflicts would dwindle their numbers.