"Violent? Not us, not now", interview with Steven Pinker, New Scientist, Oct 15 2011 (probably various excerpts online) ... To summarize a few points:
"How do you explain the decline in violence?" P: "I don't think there is a single answer". [Then P goes on to make a partial list of contributing factors such as the growth of government, especially the consolidation of kingdoms in the European Middle Ages, and] "...the transition from tribal anarchy to the first states. Watching the movie in reverse, in today's failed states violence goes through the roof". ..."...the abolition of barbaric customs such as torturing people to death for religious heresy". "Commerce, trade and exchange make other people more valuable alive than dead, and mean that people try to anticipate what the other guy needs and wants. It engages the mechanisms of reciprocal altruism, as the evolutionary biologists call it, as opposed to raw dominance". ... "The expansion of literacy, journalism, history, science - all of the ways in which we see the world from the other guy's point of view.". "Feminisation is another reason for the decline. By all measures men are the more violent gender". [then he menions WWI as "only" ninth place in the world's atrocities.] "The forces of reason, enlightenment, cosmopolitanism, women's empowerment - we should be grateful for all this and not nostalgic for a time in which everyone's world was far more constricted". [odd, no mention of the ME. Maybe I'll write him. He's a pcychology professor at Harvard, focusing on language and cognition.]