Traditions are a subject of study in several academic fields in social sciences—chiefly anthropology, archaeology, and biology—with somewhat different meanings in different fields. It is also used in varying contexts in other fields, such as history, psychology and sociology. Social scientists and others have worked to refine the commonsense concept of tradition to make it into a useful concept for scholarly analysis. In the 1970s and 1980s, Edward Shils explored the concept in detail. Since then, a wide variety of social scientists have criticized traditional ideas about tradition; meanwhile, "tradition" has come into usage in biology as applied to nonhuman animals.