American sociologist and author most noted for The Lonely Crowd: A Study of the Changing American Character (with Reuel Denney and Nathan Glazer, 1950), a work dealing primarily with the social character of the urban middle class. “The lonely crowd” became a catchphrase denoting modern urban society in which the individual feels alienated. Also entering common speech were the labels he applied to two of the three character types that he identified in the book: “inner-directed” and “other-directed.”

Educated at Harvard University (A.B., 1931; LL.B., 1934), Riesman served as clerk to U.S. Supreme Court justice Louis D. Brandeis (1935–36) and taught law at the University of Buffalo (now State University of New York at Buffalo, 1937–41). He was a professor of social sciences at the University of Chicago (1946–58) and subsequently taught at Harvard until his retirement in 1980. Among his other writings are Faces in the Crowd: Individual Studies in Character and Politics (with Glazer, 1952), comprising interviews on various issues raised in The Lonely Crowd, and Abundance for What? and Other Essays (1964), a collection of essays elaborating some of those issues, with particular reference to the sociological effects of the Cold War.

According to Riesman's theory, in preindustrial societies having a high potentiality for population growth (e.g., medieval Europe), the typical individual is “tradition-directed,” his personal values being determined by the traditions of a highly structured society or by power relations within its major divisions, such as classes, professions, castes, or clans. These values are characteristically passed intact from one generation to another. When the population is growing but has not reached the stage of crowding (e.g., western Europe from the Renaissance to the early 20th century), the “inner-directed” individual predominates. His personal values are determined early by his immediate family, are not necessarily related to any wider social forces, and are also likely to remain unchanged. In heavily industrialized societies, where the population is dense and perhaps beginning to decline, the “other-directed” individual emerges. His life is in large part shaped by “peer groups” of persons whom he resembles in age, social class, or otherwise, and he adjusts his values to conform to those of his group in a constant process of change.