Introduction

The word ‘nostalgia’ was first coined by the Swiss physician Johannes Hofer (1688/1934). For Hofer, nostalgia was synonymous with homesickness, and he equated the two in the title of his dissertation, ‘Nostalgia, oder Heimwehe’ (‘Nostalgia, or Homesickness’). For centuries, nostalgia denoted homesickness. As recently as 1943, Willis McCann conducted what, in his words, was the first ‘systematic and controlled investigation’ of nostalgia by comparing ‘one hundred college students who were or who recently had been homesick … with 100 college students who never had been homesick while away from home’ (McCann 1943: 97). Yet, current dictionary definitions reveal that nostalgia and homesickness have acquired distinct meanings. Before we can embark on a journey through the psychological literature, then, we have to identify when nostalgia and homesickness went their separate ways. It appears that their path forked during the post-war years, as by 1954 nostalgia had become a subject of psychological theorizing in its own right, with its now familiar positive connotations. The psychoanalyst Alexander Martin (1954) proposed that nostalgia plays an essential role during recuperation and consolidation phases of development:

By conceptualizing nostalgia as a springboard for growth, Martin foreshadowed recent evidence, to be reviewed later in this chapter, that the emotion is a source of approach-oriented processes, including creativity, inspiration, risk taking and goal pursuit (Sedikides and Wildschut 2016, 2020). In the same year, the social and personality psychologist Gordon Allport (1954) published his influential The Nature of Prejudice. He proposed that nostalgia could play a role in reducing prejudice and forming bonds between individuals from different social groups:

In his influential text, William James (1890) devoted separate chapters to the self and to its habits. His chapter on the self focused on the malleability of self-views and the manner in which they are diverse, encompassing disparate aspects such as the material, social and spiritual selves. By contrast, his chapter on habits highlighted the ways in which an individual becomes more and more like a particular type of person, with a particular type of disposition, over time. Whether functional or dysfunctional, habits coalescence into personality traits, and these personality traits become relatively fixed by the age of thirty.

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).

A growing body of literature indicates that problematic peer relations in childhood and adolescence are predictive of both academic and behavioral problems in school (see Kohlberg, LaCrosse, & Ricks, 1972; Kupersmidt, Coie, & Dodge, 1990; Parker & Asher, 1987, for reviews). The findings from this literature have been important for the development of criteria for defining, identifying, and screening children at risk for school maladjustment. Despite the fact that the relation between problematic peer relations and school maladjustment has been replicated across samples of children from different ethnic, geographic, and developmental groups, little is known about the mechanisms by which problematic peer relations may affect school maladjustment. The development and testing of such mechanisms has been slow, in part, because the transactional relations among social, behavioral, and academic functioning over time have been difficult to study due to methodological limitations and practical constraints. It is likely that there is a bidirectional influence between peer relations and school maladjustment; however, this chapter focuses only on one side of the equation, namely, the influence of problematic peer relations on school maladjustment. In this chapter, school maladjustment is defined in terms of behavioral, emotional, or academic difficulties that may interfere with adequate functioning in school.

One mechanism that has been proposed for understanding the impact that problematic peer relations have on children's school maladjustment suggests that poor peer relations are stressful for children due to both the experienced negative affect and the accompanying lack of social support that, in turn, increases children's vulnerability to other life stressors (Armacost, 1989; Colton & Gore, 1991; see also Birch & Ladd, this volume).