A Natural History of Peace

http://www.foreignaffairs.org/20060101faessay85110/robert-m-sapolsky/a-natural-history-of-peace.html

Summary: Humans like to think that they are unique, but the study of other primates has called into question the exceptionalism of our species. So what does primatology have to say about war and peace? Contrary to what was believed just a few decades ago, humans are not "killer apes" destined for violent conflict, but can make their own history.