I just wanted to add a few comments about the notion that diversity and cross-racial interactions on campus lead to better student attitudes. One, even enlightened places like campuses self-segregate. Often the administration helps.

Two, the idea that cross-cultural interaction improves cultural attitudes is, for the general population at least, bunk. The uncomfortable fact is that most “stereotypes,” while of course not categorically true, hold up as statistical trends across groups. When people notice these trends in the real world, it hardens their attitudes.

Thus (again, in society at large), a lack of diversity actually seems to correlate with better racial attitudes. In the Democratic primaries, whites in the most-white states voted most heavily for Obama, and around the world, most violent flare-ups happen when ethnicities, nationalities, or religions meet. Like it or not, voluntary segregation through the nation-state system has been a blessing for world harmony: We live and let live, but we live separately.

Of course, if there’s anywhere this is possibly not true, it should be on college campuses — as George writes, most beneficiaries of affirmative action aren’t all that different class-wise from the students who got in on merit, so it’s conceivable that a diverse campus might give the impression that all cultures are more or less the same. Also, college kids are more likely to have the intelligence required to distinguish between statistical trends and individual exceptions.

But at the same time, aggressive affirmative action creates a merit disparity on campus, and this disparity in some cases may be noticeable.