To the list of forbidden ideas on American college campuses, add “bourgeois norms”—hard work, self-discipline, marriage and respect for authority. Last month, two law professors published an op-ed in the Philadelphia Inquirer calling for a revival of the “cultural script” that prevailed in the 1950s and still does among affluent Americans: “Get married before you have children and strive to stay married for their sake. Get the education you need for gainful employment, work hard, and avoid idleness. . . . Eschew substance abuse and crime.” The weakening of these traditional norms has contributed to today’s low rates of...