In their search to explain social change, sociologists sometimes examine historical data to better understand current changes and movements. They also rely on three basic theories of social change: evolutionary, functionalist, and conflict theories.
Sociologists in the 19th century applied Charles Darwin's (1809–1882) work in biological evolution to theories of social change. According to evolutionary theory, society moves in specific directions. Therefore, early social evolutionists saw society as progressing to higher and higher levels. As a result, they concluded that their own cultural attitudes and behaviors were more advanced than those of earlier societies.
Identified as the “father of sociology,” Auguste Comte subscribed to social evolution. He saw human societies as progressing into using scientific methods. Likewise, Emile Durkheim, one of the founders of functionalism, saw societies as moving from simple to complex social structures. Herbert Spencer compared society to a living organism with interrelated parts moving toward a common end. In short, Comte, Durkheim, and Spencer proposed unilinear evolutionary theories, which maintain that all societies pass through the same sequence of stages of evolution to reach the same destiny.
Contemporary social evolutionists like Gerhard Lenski, Jr., however, view social change as multilinear rather than unilinear. Multilinear evolutionary theory holds that change can occur in several ways and does not inevitably lead in the same direction. Multilinear theorists observe that human societies have evolved along differing lines.
Functionalist sociologists emphasize what maintains society, not what changes it. Although functionalists may at first appear to have little to say about social change, sociologist Talcott Parsons holds otherwise. Parsons (1902–1979), a leading functionalist, saw society in its natural state as being stable and balanced. That is, society naturally moves toward a state of homeostasis. To Parsons, significant social problems, such as union strikes, represent nothing but temporary rifts in the social order. According to his equilibrium theory, changes in one aspect of society require adjustments in other aspects. When these adjustments do not occur, equilibrium disappears, threatening social order. Parsons' equilibrium theory incorporates the evolutionary concept of continuing progress, but the predominant theme is stability and balance.
Critics argue that functionalists minimize the effects of change because all aspects of society contribute in some way to society's overall health. They also argue that functionalists ignore the use of force by society's powerful to maintain an illusion of stability and integration.
Conflict theorists maintain that, because a society's wealthy and powerful ensure the status quo in which social practices and institutions favorable to them continue, change plays a vital role in remedying social inequalities and injustices.
Although Karl Marx accepted the evolutionary argument that societies develop along a specific direction, he did not agree that each successive stage presents an improvement over the previous stage. Marx noted that history proceeds in stages in which the rich always exploit the poor and weak as a class of people. Slaves in ancient Rome and the working classes of today share the same basic exploitation. Only by socialist revolution led by the proletariat (working class), explained Marx in his 1867 Das Kapital, will any society move into its final stage of development: a free, classless, and communist society.
Marx's view of social change is proactive; it does not rely on people remaining passive in response to exploitation or other problems in material culture. Instead, it presents tools for individuals wishing to take control and regain their freedom. Unlike functionalism and its emphasis on stability, Marx holds that conflict is desirable and needed to initiate social change and rid society of inequality.
Critics of Marx note that conflict theorists do not always realize that social upheaval does not inevitably lead to positive or expected outcomes.