Sociologists in the main define their field as the scientific or systematic study of human groups, human societies, or human social behavior, a formulation that does not imply any spatial limit upon its scope. In practice, most sociological studies are conducted within one society, and few theoretical propositions can find support in research results based on comparable data from many societies. To counter such undesirable parochialism, this paper calls urgently for recognition of the need for much more emphasis on cross-societal comparative research and proposes ways in which such an expansion can be facilitated.