Economic determinism

The first theory, economic determinism, reflects the interest many sociologists had in the thought of Karl Marx, such as the idea that social differentiation and class conflict resulted from economic factors. This approach had its greatest popularity in Europe, where it remained a strong influence on some sociologists until the 1980s. It did not gain a significant foothold in the United States, because American society was thought to be socially mobile, classless, and oriented to the individual. This neglect of Marxism by American sociologists, however, was not due to scholarly ignorance. Sociologists of all periods had read Marx as well as Charles A. Beard’s economic interpretation of American history and the work of Werner Sombart (who had been a Marxist in his early career). Instead, in the 1960s, neo-Marxism—an amalgam of theories of stratification by Marx and Max Weber—gained strong support among a minority of sociologists. Their enthusiasm lasted about 30 years, ebbing with the breakup of the Soviet system and the introduction of postindustrial doctrines that linked class systems to a bygone industrial era. The persistence of social and economic inequality is now explained as a complex outcome of factors, including gender, race, and region, as well as global trade and national politics.

Human ecology

Representing the second theoretical area, human geographers—Ellsworth Huntington, Ellen Semple, Friedrich Ratzel, Paul Vidal de La Blache, Jean Brunhes, and others—emphasized the impact of climate and geography on the evolution of those societies that flourished in temperate zones. Their theories found no place in mainstream sociological thought, however, except for a brief period in the 1930s when human ecology sought to explain social change by linking environmental conditions with demographic, organizational, and technological factors. Human ecology remains a small but vital part of sociology today.

Social psychology

Psychological theories emphasized instincts, drives, motives, temperament, intelligence, and human sociability in social behaviour and societal evolution. Social psychology modifies these concepts to explain the broader phenomena of social interaction or small group behaviour. Although American sociology even today retains an individualistic (and therefore psychological) bias, by the 1930s sociologists had concluded that psychological factors alone could not explain the behaviour of larger groups and societies.

Cultural theory

Finally, cultural theories of the 1930s emphasized human ability to innovate, accumulate, and diffuse culture. Heavily influenced by social and cultural anthropology, many sociologists concluded that culture was the most important factor in accounting for its own evolution and that of society. By 1940 cultural and social explanations of societal growth and change were accepted, with economic, geographic, and biopsychological factors playing subsidiary roles.

Early functionalism

Scholars who established sociology as a legitimate social science were careful to distinguish it from biology and psychology, fields that had also begun to generalize about human behaviour. They did this by developing specific methods for the study of society. French sociologist Émile Durkheim (1858–1917), prominent in this regard, argued that various kinds of interactions between individuals bring about certain new properties (sui generis) not found in separate individuals. Durkheim insisted that these “social facts,” as he called them—collective sentiments, customs, institutions, nations—should be studied and explained on a distinctly societal level (rather than on an individual level). To Durkheim the interrelations between the parts of society contributed to social unity—an integrated system with life characteristics of its own, exterior to individuals yet driving their behaviour. By positing a causal direction of social influence (from group to individual rather than the reverse, the model accepted by most biologists and psychologists of the time), Durkheim gave a much-needed framework to the new science of sociology. Some writers called this view “functionalism,” although the term later acquired broader meanings.

Durkheim pointed out that groups can be held together on two contrasting bases: mechanical solidarity, a sentimental attraction of social units or groups that perform the same or similar functions, such as preindustrial self-sufficient farmers; or organic solidarity, an interdependence based on differentiated functions and specialization as seen in a factory, the military, government, or other complex organizations. Other theorists of Durkheim’s period, notably Henry Maine and Ferdinand Tönnies, made similar distinctions—status and contract (Maine) and Gemeinschaft und Gesellschaft (Tönnies)—and predicted that civilization would progress along the lines of specialization, contractual relations, and Gesellschaft.

Later anthropologists, especially Bronisław Malinowski and A.R. Radcliffe-Brown, developed a doctrine of functionalism that emphasized the interrelatedness of all parts of society. They theorized that a change in any single element would produce a general disturbance in the whole society. This doctrine eventually gained such a following among social anthropologists that some advocated a policy of complete noninterference, even with objectionable practices in preliterate societies (such as cannibalism or head-hunting), for fear that eliminating the practice might produce far-reaching social disorganization.