“At this point, the figures on chimpanzee cooperative violence suggest that an individual’s yearly risk of death from intercommunity warfare ranges from 0.069 to 0.287 percent. That’s generally higher than the risk of death from war for people living in modern nation-states, but it’s still within the same general range as the risk of death in war for contemporary people living in pre-state hunter and farmer societies”

That is from the interesting, lively, and often harrowing “The Moral Lives of Animals”, with a hat tip to Tyler Cowen.