Far from spending their college years in a meritocratic melting pot, the New Elite spend school with people who are mostly just like them — which might not be so bad, except that so many of them have been ensconced in affluent suburbs from birth and have never been outside the bubble of privilege. Few of them grew up in the small cities, towns or rural areas where more than a third of all Americans still live…

When the New Elite get around to marrying, they don’t marry just anybody. One of the funniest and most bitingly accurate parts of “Bobos in Paradise” was Brooks’s analysis of the New York Times’s wedding announcements. Go back to 1960, and the page was filled with brides and grooms who grew up wealthy but whose educations and occupations did not offer much indication that they were going to set the world on fire. Look at the page today, and it is studded with the mergers of fabulous résumés…

We are watching the maturation of the cognitive stratification that Richard J. Herrnstein and I described in “The Bell Curve” back in 1994. When educational and professional opportunities first opened up, we saw social churning galore, as youngsters benefited from opportunities that their parents had been denied. But that phase lasted only a generation or two, slowed by this inescapable paradox:

The more efficiently a society identifies the most able young people of both sexes, sends them to the best colleges, unleashes them into an economy that is tailor-made for people with their abilities and lets proximity take its course, the sooner a New Elite — the “cognitive elite” that Herrnstein and I described — becomes a class unto itself. It is by no means a closed club, as Barack Obama’s example proves. But the credentials for admission are increasingly held by the children of those who are already members. An elite that passes only money to the next generation is evanescent (“Shirtsleeves to shirtsleeves in three generations,” as the adage has it). An elite that also passes on ability is more tenacious, and the chasm between it and the rest of society widens.