The common wisdom is that we’re getting more violent all the time. Witness the genocides and world wars of the last century. But cognitive psychologist Steven Pinker says we have it all wrong. And in his 800 page book “The Better Angels of Ourselves” he makes the case for how violence has declined. Tribal warfare was actually nine times more deadly as the war and genocide in the 20th century. The murder rate of Medieval Europe was more than thirty times what it is today. Slavery, sadistic punishment, and gruesome executions were common parts of life for millennia. Then they were mostly abolished. Wars between developed countries have vanished, and even in the developing world, wars kill a fraction of the people they did a few decades ago. Rape, battering, hate crimes, deadly riots, child abuse, cruelty to animals – all down. Steve Paulson asked Pinker why?