…[T]he Waodani are, as near as we’ve been able to tell, the most violent [society on earth]. … Virtually everybody’s ancestors were speared to death. We would ask, “Why did they do that?” “They were angry.” And that was the answer. It turns out that they had these two paramount values: egalitarianism and autonomy. And if something comes along to infringe your autonomy, this is a violation of the way things ought to be. And the way that one restores this sense of autonomy, this sense of control, is to kill.
Anthropologist Clayton Robarchek in the documentary Beyond the Gates of Splendor