Any recurring pattern of interaction among individuals playing different roles may be said to possess or to constitute a social structure. One may therefore speak of the social structure of the American middle-class family, of General Motors or Harvard University, or of a juvenile gang. Or it may even be American society as a whole. However, many of the major subfields of sociology involve the naming of a recognized area of human activity receded by the phrase "the society of". Established fields of teaching and research include sociologies of politics, law, religion or education. What else do sociologists study besides human relationship? They also study some social phenomena that are not the subjects of any other scholarly discipline. These include marriage and family; crime and deviance and social inequality and stratification.