Until recently, psychologists have neglected the issue of childhood loneliness, perhaps because, in part, of early theorists' assertions that loneliness does not become a viable experience until adolescence. Sullivan (1953), for example, described loneliness as a “phenomenon ordinarily encountered in preadolescence and afterward” (p. 261) when the need for intimacy in the context of a close friendship or “chumship” develops. Likewise, Weiss (1973) argued, “Loneliness proper becomes a possible experience only when, in adolescence, parents are relinquished as attachment figures” and the individual can identify “unsatisfactory friendly acquaintances” (p. 90).

Recent investigations of children's understanding of loneliness, however, clearly challenge these ideas (Hymel et al., this volume), as children as young as 5 have been identified who are lonely (Cassidy & Asher, 1992; 1993). In fact, all but 7% of a sample of kindergarten and first-grade children studied by Cassidy and Asher (1992) were able to define loneliness as a basically negative state and could produce relevant responses when asked about the meaning of loneliness. Moreover, this ability varied as a function of sociometric status, as more popular children evinced greater complexity in their understanding of loneliness (Cassidy & Asher, 1993). Similar findings regarding children's basic understanding of loneliness have also emerged from studies involving third- through eighth-grade children (Hymel et al., this volume) and third- through sixth-grade children with and without mild mental retardation (Williams & Asher, 1992). These investigations document the existence of loneliness considerably earlier than Sullivan (1953) and Weiss (1973) originally claimed (see also Burgess et al., this volume).