At all ages human beings benefit from having relationships with other people who spend time with them, help them, give them advice, and affirm their self-worth. This simple fact is the basis for current theories and research on supportive relationships (Belle, 1989; Sarason, Sarason, & Pierce, 1990; Veiel & Baumann, 1992). The construct of social support first gained prominence in the fields of psychiatry and psychosocial epidemiology (e.g., Cobb, 1976). Then sociologists, clinical psychologists, and other researchers interested in physical and mental health adopted the construct (see Cohen & Wills, 1985; Sarason et al., 1990). During the 1980s, the idea of supportive relationships also sparked research in the field of social development (e.g., Berndt & Perry, 1986; Reid, Landesman, Treder, & Jaccard, 1989). Developmental psychologists have, in particular, examined the nature and effects of support from two sources: family members, especially parents; and peers, especially best friends.