a theoretical state of balance in a social system referring both to an internal balance between interrelated social phenomena and to the external relationship the system maintains with its environment. It is the tendency of the social system, when disturbed, to return to its original state, because any small change in a social element is followed by changes in other related elements that work toward diminishing the first disturbance.

American sociologist Talcott Parsons (Parsons, Talcott) postulated that all social systems tend to approximate a state of equilibrium, although no concrete system will actually reach a perfectly equilibrated state. To Parsons, the fully equilibrated society served as a theoretical reference point rather than as a description of a real system. Some students of cultural change, however, maintain that the basic tendencies in social and cultural systems are toward change rather than toward states of equilibrium (see social change).