In this chapter, we are interested in loneliness in children and adolescents and its relevance to their adjustment. The subjective experience of loneliness as a negative affective state associated with deficits in the formation of social relationships has long been recognized as an important area of study in adults (see Marangoni & Ickes, 1989, for a review). However, until the past decade, loneliness was relatively neglected in the child and adolescent literature. In recent years, a growing body of literature has emerged to suggest that children and adolescents experience feelings of loneliness related to problems in social relationships. Indeed, approximately 10% of children between kindergarten through eighth grade report feeling very lonely (Asher et al., 1984; Asher & Wheeler, 1985; Cassidy & Asher, 1992; Parkhurst & Asher, 1992). These and other studies highlight the fact that loneliness can occur with alarming frequency across child and adolescent development.

Loneliness is related to a range of emotional, social, and behavioral problems for children, adolescents, and adults. Emotional problems include low self-esteem (Hymel et al., 1990), depression (Goswick & Jones, 1981), and social anxiety (Moore & Schultz, 1983). Social problems include peer rejection and victimization, lack of friendships, and lack of highquality friendships (Asher et al., 1990; Asher & Wheeler, 1985; Boivin & Hymel, 1996; Crick & Ladd, 1993; Kochenderfer & Ladd, 1996; Parker & Asher, 1993b). Behavioral problems include shyness, social withdrawal, spending more time alone (Horowitz, French, & Anderson, 1982; Jones et al., 1981; Russell et al., 1980), dating frequency (Brennan, 1982), and decreased participation in religious and extracurricular school activities (Brennan, 1982).