摘要: Sociologists since Simmel have been interested in social circles as essential features of friendship networks. Although network analysis has increasingly used to uncover patterns among relationships, theoretical explanations these inadequate. This paper presents a theory the organization ties. The approach is based upon Homans's concepts activities, interactions, and sentiments concept extra-network foci organizing activities interaction. contrasted with Heider's balance theory. Implications for transitivity, bridges, density personal networks are discussed presented propositions. focus shown help explain friendships 1965-66 Detroit Area Study. intended step toward development integrated interrelationships between other aspects structure. data discussed. long recognized importance relations that connect individuals each other. (1955) described modern society consisting loosely connected relationships. Granovetter (1973) indicated general significance communication, community organization, conflict. Various studies supported this picture networks, including Moreno's sociometry (1953), Milgram's "small world" experiments (1967), Kadushin's observations (1966). Unfortunately, study often carried out without concern origins larger context. Most ends description labeling patterns; when offered, they frequently rely inherent tendencies within become consistent, balanced, or transitive. As consequence such atheoretical and/or self-contained approaches, collected techniques devised