THE Supreme Court listened anew last week to arguments about affirmative action in higher education, and we heard yet again about the push by colleges to assemble diverse student bodies.

That’s a crucial effort.

It’s also an incomplete and falsely reassuring one.

Have you spent much time on campuses lately? Leafed through schools’ promotional literature? Listened to their come-ons?

If so, you’ve probably noticed how often they promise students academic and social experiences customized to their already-established preferences, tailor-fitted to their predetermined interests, contoured to the particular and peculiar niches they want to inhabit.

There’s a profusion of affinity groups. There are themed living arrangements that allow students with similar backgrounds and overlapping hobbies to huddle together. In terms of curriculum, there’s enormous freedom, which can translate into the ability to chart and stick to a narrow path with fellow travelers whose perspectives are much the same as yours.