NEAL CONAN, HOST:

This is TALK OF THE NATION. I'm Neal Conan in Washington. Suicide bombers explode themselves in the heart of Damascus; tens of thousands killed in that Syrian civil war and counting; the U.S. ambassador to Libya and four other Americans murdered in an attack in Benghazi on the anniversary of 9/11; in Minneapolis, a gunman kills four people at a local post office before shooting and killing himself; just a few of the recent headlines from a world seemingly afflicted by war and violence.

But Joshua Goldstein argues the past 10 years have seen fewer war deaths than any decade in the past 100 years. And Harvard psychologist Steven Pinker goes even further: We may be living in the most peaceful period in the history of our species. Really? And if so, why?

Read more, and listen to the interview, at WKU Public Radio