22 Friendship Across the Life Span
Other chapters of this book cover friendships in childhood ( chapter 1, Erdley &
Day) and old age ( chapter 3, Adams, Hahmann, & Blieszner).
We first provide an overview on how friendships of young adults differ from
(and are similar to) friendships during other developmental periods. Second, we
summarize individual differences in friendships related to personality characteris-
tics and other social relationships, for example, family members. Third, we address
the normative development of friendship number and quality during young and
middle adulthood. Fourth, we consider dynamic longitudinal transactions between
friendships and personality. Finally, we discuss what is gained from studying the
interdependencies among friendships and other relationships within people’s per-
sonal networks.
Friendships in Young and Middle Adulthood
During childhood and adolescence, friends are mainly other children from the
same (pre- ) school class or neighborhood. Young adults in part maintain school
friends (Asendorpf & Wilpers, 1998; Degenne & Lebeaux, 2005) and also acquire
additional friends in close spatial proximity in daily life. For example, the closer
young adults live within college dorms, the more likely they are to become friends
(Festinger, Schachter, & Back, 1950). People working in the same work unit are
also more likely to become friends compared with people working in differ-
ent units of the same company (Stackman & Pinder, 1999). In a study by Back,
Schmukle, and Egloff (2008), merely sitting next to each other during an intro-
ductory day increased students’ likelihood of being friends 1 year later compared
with other students, who were also attending the introduction and also met later
during study courses. Therefore, in adulthood, people often become friends with
others they meet regularly: in the neighborhood, at work, in sports clubs (Miche,
Huxhold, & Stevens, 2013), or through one’s romantic partner or existing friends
(M. P. Johnson & Leslie, 1982).
In young and middle adulthood, friendships gain new functions and complex-
ity compared with childhood friendships. While childhood friendships focus on
play (cf. Erdley & Day, this volume; Fehr, 1996), during adolescence, friendships
begin to replace parents as confidants and companions for leisure time activities
(Fraley & Davis, 1997; Hartup & Stevens, 1997). Importantly, adolescents’ friend-
ships also serve as training models to prepare for intimate romantic relationships
(Fraley, Roisman, Booth- LaForce, Owen, & Holland, 2013; Simpson, Collins,
Tran, & Haydon, 2007). Although romantic partners become more important dur-
ing young and middle adulthood as compared with adolescence, friends largely
maintain their function as confidant, attachment figure, and partner for leisure
activities. In addition to providing validation and emotional closeness, friends pro-
vide practical support as well (Fehr, 1996), for example, by helping move or lending