It is true that raids and battles killed a tiny percentage of the numbers that die in modern warfare. But in tribal violence, the clashes are more frequent, the percentage of men in the population who fight is greater, and the rates of death per battle are higher.

If you aren't just brought up in your tribe but interact with other people either directly or vicariously, through journalism and literature, you see what life is like from other points of view and are less likely to demonize them or dehumanize others and more likely to empathize with them.

If you look in general at people who live in anarchy, they have quite high rates of death from either homicide or warfare or both. Anarchy is one of the main reasons for violence, and it may be the most important.

Steven Pinker Quotes