Diversity and Affirmative Action Yield Benefits.

"In exploring (relations among different groups), one often encounters a pessimism built around the notion that humans...are hard-wired for xenophobia. Some brain-imaging studies have appeared to support this view in a particularly discouraging way. There is a structure deep inside the brain called the amygdala, which plays a key role in fear and aggression, and experiments have shown that when subjects are presented with a face of someone from a different race, the amygdala gets metabolically active-- aroused, alert, ready for action. This happens even when the face is presented 'subliminally', which is to say, so rapidly that the subject does not consciously see it.

"More recent studies, however, should mitigate this pessimism. Test a person who has a lot of experience with people of different races, and the amygdala does not activate. Or, as in a wonderful experiment by Susan Fiske of Princeton University, subtly bias the subject beforehand to think of people as individuals rather than as members of a group, and the amygdala does not budge...

"The first half of the twentieth century was drenched in the blood spilled by German and Japanese aggression, yet only a few decades later it is hard to think of two countries more pacific. Sweden spent the seventeenth century rampaging through Europe, yet it is now an icon of nurturing tranquility."

Robert M. Sapolsky, A Natural History of Peace, Foreign Affairs, January/February 2006, pp. 119-120