I encourage anyone who reads Pinker's book to also consider Nassim Taleb's critique http://www.fooledbyrandomness.com/longpeace.pdf
"Taleb shows no signs of having read Better Angels with the slightest attention to its content. Instead he has merged it in his mind with claims by various fools and knaves whom he believes he has bettered in the past. The confusion begins with his remarkable claim that the thesis in Better Angels is “identical” to Ben Bernanke’s theory of a moderation in the stock market. Identical! This alone should warn readers that for all of Taleb’s prescience about the financial crisis, accurate attribution and careful analysis of other people’s ideas are not his strong suits."