The global causes of postfamilialism are diverse, and many, on their own, are socially favorable or at least benign. The rush of people worldwide into cities, for example, has ushered in prosperity for hundreds of millions, allowing families to be both smaller and more prosperous. Improvements in contraception and increased access to it have given women far greater control of their reproductive options, which has coincided with a decline in religion in most advanced countries. With women’s rights largely secured in the First World and their seats in the classroom, the statehouse, and the boardroom no longer tokens or novelties, children have ceased being an economic or cultural necessity for many or an eventual outcome of sex. …

Crudely put, the lack of productive screwing could further be screwing the screwed generation. …

The results haven’t been pretty. In some places in Japan, particularly in the countryside, there are already too few working adults remaining to take care of the elderly, and kodokushi, or “lonely death,” among the aged, the unmarried, and the childless, is on the rise. Long a model of frugality, the demographically declining nation now has by far the high-income world’s highest rate of public indebtedness as spending on the elderly has shot past what the state can extract from its remaining productive workers. Last month, the nation’s new finance minister, Taro Aso, outright said that the elderly should be given grace to “hurry up and die.” This situation will not be made better by a desexualized younger Japanese generation: one in three young men ages 16 to 19 express “no interest” in sex—and that may be a good thing, given that 60 percent of young women of the same age share their indifference.