The evidence that tribal peoples often damage their environments and make war.

Why is this idea dangerous? Because too many people today believe that a reason not to mistreat tribal people is that they are too nice or wise or peaceful to do those evil things, which only we evil citizens of state governments do. The idea is dangerous because, if you believe that that’s the reason not to mistreat tribal peoples, then proof of the idea’s truth would suggest that it’s OK to mistreat them. In fact, the evidence seems to me overwhelming that the dangerous idea is true. But we should treat other people well because of ethical reasons, not because of naïve anthropological theories that will almost surely prove false.