“Irregular behavior that deviates from what is considered normal. In sociology, the use of the term implies that the behavior in question is performed in secret and mainly for reasons of self-interest, as for example in the case of certain unusual sexual practices. This may be contrasted with ‘non-conforming behavior,’ which usually refers to public violations of social norms, often carried out specifically to promote social change. Thus the political or religious dissenter proclaims his or her deviance to as wide an audience as possible. The implications of this distinction for theories of deviance are discussed fully by Robert K. Merton in his essay ‘Social Problems and Sociological Theory’ (R.K. Merton and R. Nisbet, Contemporary Social Problems, 1971).
Excerpted from: Matthews, Gordon, ed. Oxford Dictionary of Sociology. New York: Oxford University Press, 1994.