Steven Pinker: Why Violence Is VanishingThis copy is for your personal, non-commercial use only. Distribution and use of this material are governed by our Subscriber Agreement and by copyright law. For non-personal use or to order multiple copies, please contact Dow Jones Reprints at 1-800-843-0008 or visit www.djreprints.com. http://online.wsj.com/article/SB10001424053111904106704576583203589408180.html We believe our world is riddled
How 'Black Widows' Became Spiders—and Terrorists
