SO I SPOKE AT AN EVENT TONIGHT, TALKING ABOUT CIVILIAN DISASTER RELIEF AND SOCIAL COHESION, and a guy came up to me afterward saying that since Robert Putnam found that diversity is associated with decreased social trust, how did I feel about a bunch of white people going off to start their own country. (My response: Unenthused). But you see this sort of thing on the Internet enough that some people believe it, and while Putnam’s point is supported by research, I don’t think it actually supports the solution. “Diversity,” I suspect, is one of those things that actually is a social construct. If you make people hyperaware of their differences — as is done on college campuses today — you can make things much worse than they otherwise would be. (See also Tito’s Yugoslavia). If you encourage people to think about what they have in common, you can make things much better. And where it suits their interests, politicians will create ethnic cleavages. (Hutus and Tutsis are both “black” in American conception, but politicians were still able to inflame passions that led to genocide.) My prediction is that if you created some sort of racially segregated society, politicians would soon be at work finding other differences to inflame, differences that nobody’s even aware of now. The only real answer is a strong social norm that supports, for example, our common humanity and, in this country, our common Americanness. This seems to be what ordinary Americans believe, and act upon, but politicians will do whatever it takes to gain power. Keeping politicians in check is the key to getting along. Can we do more of that?