Harvard sociologist Robert Putnam has recently upset a lot of people on the left with his study finding that diversity has its downside — in more “diverse” communities, there is less social cooperation and more of what he calls “hunkering down.”

In today’s Wall Street Journal, Daniel Henninger comments on Putnam’s paper. He sums up his take on the controversy writing, “My own model for the way forward in a 21st century American society of unavoidable ethnic multitudes is an old one, a phrase found nowhere in the Putnam study or any commentary on it: the middle class. Its assimilating virtues may be boring, but it works, if you work at getting into it.”

So what does all this have to do with the mania for “diversity” in higher education? Just as Putnam finds much less virtue than many had supposed for diversity in communities, I think it’s clear that diversity on campus has far less benefit than its supporters think. Often students who are admitted just so a school can say that it has reached a “critical mass” of students from “underrepresented groups” tend to cluster together. We don’t get the hoped-for harmony and understanding across racial and cultural groups, but just a steady stream of demands for special benefits and treatment by spokespersons for those groups.

At the college level, the equivalent of Henninger’s laissez-faire policy of assimilation through economic success would be a policy of admitting and hiring without concern for a person’s group identity. Schools should just focus on educational success and when they do, that will become the common denominator among the students and faculty members.