Sociology-the systematic study of human behaviour in social context. Functionalism-a sociological school of thought that stresses how human behaviour is governed by social structures that are based mainly on shared values and that contribute to social stability. All functionalist explanations hold that social phenomena persist if they contribute to social stability-and die off if they don"t. Social class-a position people occupy in a hierarchy that is shaped by economic criteria, including wealth and income. Conflict theory-a sociological school of thought that focuses on how large social structures, such as the relations among classes, produce social stability in some circumstances and social change in others. Theory-a conjecture about the way observed facts are related. Symbolic interactionism-a sociological school of thought that highlights how interpersonal communication in face- to-face settings creates subjective meanings that people attach to their social circumstances. Gender-one"s sense of being masculine or feminine as conventionally defined by society.