Actual contemporary evidence indicates blacks are doing better in a fairer society. Crime rates, incarceration rates and teen pregnancy rates are way down from the 1990s, as Columbia undergraduate Coleman Hughes writes in Quillette. And bachelor’s degrees and life expectancies are way up. Not entirely unconnected with this is the perhaps politically awkward fact that lower-income and minority Americans have been experiencing record-low unemployment and higher-than-average wage gains during the last three years.

Complaints still come in saying that social mobility is decreasing, and that various elite educational and economic categories do not contain the same percentages of blacks and some other minorities as the larger society. But it is an illusion of social engineers that a free society can be arranged with identical percentages of every identifiable group in every identifiable category. And it is a fact — a melancholy fact, perhaps, but a fact — that an increasingly fair society will have a decreasing degree of social mobility.

That’s because in a fair society, people tend to end up in places where they started off. In a society like ours, with increasing assortative mating (people marrying those with similar interests and abilities), both nature and nurture — hereditary traits and child-rearing practices — tend to produce a generation of relatively few people with the capacity and inclination to climb, or fall down from, the socioeconomic ladder.