Murray identifies what he calls the “founding virtues”—marriage, industriousness, honesty, and religiosity—that were once shared by all Americans and held us together in a common culture. That culture was still intact on November 21, 1963, the day before the Kennedy assassination that Murray chooses as his benchmark. In graph after graph drawn from the sociological literature, he shows how these four qualities have deteriorated—not among the college educated, who spend most of their time disparaging those virtues, but in blue—collar communities where people are rarely educated beyond high school. By way of illustration, he applies this data to two real places, Belmont, an upscale suburb of Boston dominated by college graduates, and Fishtown, a working-class neighborhood on the fringe of Philadelphia where the once strong ethic of marriage and family is now falling apart.