Time was, colleges and universities acted in loco parentis to moderate undergraduates’ comportment, particularly regarding sex and alcohol. Institutions have largely abandoned this, having decided that students are mature possessors of moral agency. But institutions have also decided that although undergraduates can cope with hormones and intoxicants, they must be protected from discomforting speech, which must be regulated by codes and confined to “free speech zones.” Uncongenial ideas must be foreshadowed by “trigger warnings,” lest students, who never were free-range children and now are as brittle as pretzels, crumble. Young people shaped by smothering parents come to college not really separated from their “helicopter parents.” Such students come convinced that the world is properly devoted to guaranteeing their serenity, and that their fragility entitles them to protection from distressing thoughts.

As Penn State historian Gary Cross says, adolescence is being redefined to extend well into the 20s, and the “clustering of rites of passage” into adulthood — marriage, childbearing, permanent employment — “has largely disappeared.” Writing in the Chronicle of Higher Education, Cross says that “delayed social adulthood” means that “in 2011, almost a fifth of men between 25 and 34 still lived with their parents,” where many play video games: “The average player is 30 years old.” The percentage of men in their early 40s who have never married “has risen fourfold to 20 percent.”