Stay in the arts long enough, and all this thinking about violence will lead you to questions about human nature. The anthropology shows there’s wide variation between cultures in their levels and frequencies of lethal violence. What’s surprising is how little evidence Horgan could dig up for violent group conflict in human prehistory. My only quibble with the book is that the focus on lethal violence and war obscures the general aggressive tendencies in people. These general aggressive tendencies are not the same as lethal violence, but they’re related.