Delineation of the social network and differences in network size

TLDR: A long-standing tradition in the field of gerontology of studying the social networks of the aged can be traced back to the work of Antonucci as discussed by the authors, who defined a social network as a set of persons with whom specific types of support are exchanged, or include relationships that are to some degree important to the focal person.

Abstract: There is a long-standing tradition in the field of gerontology of studying the social networks of the aged. Most studies focus on the support networks of the elderly and describe their personal networks by means of the supportive features of their relationships. Some studies define a social network as a set of persons with whom specific types of support are exchanged (Fischer, Jackson, Stueve, Gerson, Jones, & Baldassare, 1977; Wellman, 1981) or include relationships that are to some degree important to the focal person (Kahn & Antonucci, 1980). All these definitions narrow the study of social networks down to structures in which support is exchanged (Antonucci, 1985). However, individuals maintain many relationships in which very little if any support is exchanged. Social interaction can also be based on more or less institutionalized formal relationships, for example, those with relatives, coworkers, fellow members of organizations, and neighbours. Researchers who use these institutionalized relationships as their point of departure take living arrangements, household composition, marital status, and employment status as criteria for network membership (Berkman & Syme, 1979; Brody, Poulshock, and Masciocchi, 1978; Lin, 1982; Shanas, L979).