This document summarizes several sociological theories of deviance: structural-functionalism, conflict theory, and symbolic interactionism. Under structural-functionalism, it describes Robert Merton's strain theory, which identifies five types of deviance that can result from a mismatch between socially prescribed goals and legitimate means to achieve them. It also describes Emile Durkheim's functionalist theory that deviance affirms social norms and promotes social change. Conflict theory holds that deviance results from social inequality and power imbalances. Symbolic interactionism includes Edwin Sutherland's differential association theory of learned deviance, Walter Reckless' control theory about internal and external controls on deviance, and labeling theory about how people accept deviant identities