Since ancient times, racial, religious, ethnic, and nationalistic prejudices have fueled violent conflict, and this propensity seems to be continuing unabated well into the second decade of the 21st century. A toxic brew of lethal weapons of mass destruction, religious
and political leaders (of nation-states or of their own radical fringes) with apocalyptic visions of eradicating evil (real and imagined), and media sources inciting hatred and providing explicit instructions for terrifying violence seems perpetually on the brink of boiling over. In light of these forces, the notion of humans extinguishing themselves as a species seems more like a sober actuarial prediction than a science fiction prophecy. Surely, then, understanding the psychological underpinnings of prejudice in hopes of fostering constructive efforts toward amelioration should continue to be a high priority for social scientists of all stripes.