A survey of anthropology defines the field as the study of humans as members of social and racial groups and applies biological, psychological, and cultural evidence to contemporary social problems. It examines race as a fluid, overlapping set of physical and hereditary traits and considers environmental influences, intelligence testing, and the social relations among groups. It analyzes nationalism, language, and political organization as bases for collective identity and critiques eugenic and deterministic proposals while weighing hereditary and environmental explanations for crime and behavior. It also addresses cultural stability and change, the persistence of habitual thought and action, and the role of education in individual development and social transformation.