It depends on whether you have social constructs in place which take priority over human behaviour.
Remove all of this.. what happens.. humans will eventually go back to primal instincts
Remove all of this.. what happens.. humans will eventually go back to primal instincts
Humans are social creatures, but not social with the entire world.
The modern view is that most likely hunter-gatherer societies, which didn't have fixed lands and had no general reason to be territorial, had little warfare. It is only with agricultural societies, where competition for land becomes a factor, that we start finding evidence of warfare, as far as I understand.
What's interesting it's that researchers that lived with the Yanomami and other Amazonian peoples noted that most inter tribal conflicts weren't about competition for food sources-that was rather plenty- but instead for women. In polygamous societies, high status males acquired many wives and young males frequently kidnapped neighboring tribe's women which sparked constant retaliatory raids.