6 Friendship Across the Life Span
the other, and that both give each other high ratings (e.g., Berndt & Perry, 1986). In
a comparison of various operational definitions of friendship, Erdley, Nangle, and
Gold (1998) found that the definition requiring reciprocated positive nominations
was the most restrictive, identifying fewer friendship dyads, whereas definitions using
ratings were more lenient, identifying more friendship dyads. Erdley and colleagues
(1998) suggested that the definition requiring mutual positive nominations identifies
friendships that are qualitatively distinct. That is, it seems likely that these friendships
are best friendships, whereas the use of more lenient definitions may identify “good”
friendships, in which dyad members like one another, but do not necessarily view
one another as close friends. Notably, many studies employing positive nominations
have restricted children to nominating a maximum number of peers, typically three
(e.g., Nangle et al., 2003). However, recent research has indicated that using unlimited
nominations is more reliable (Marks, Babcock, Cillessen, & Crick, 2012). Allowing
unlimited nominations is especially recommended for assessing the presence of
friendships in adolescents, given that the reference group of peers in middle and high
schools tends to be large (Cillessen, 2009).
In addition to measuring the existence of a friendship, it is important to assess
friendship quality, or the degree to which the friendship is fulfilling key provi-
sions (Bukowski & Hoza, 1989). Several measures of friendship quality have been
developed, with the respondent usually evaluating a specific friendship identified
as reciprocated. These measures, such as the Friendship Quality Questionnaire
(Parker & Asher, 1993) and the Friendship Qualities Scale (Bukowski, Hoza, &
Boivin, 1994) ask children to rate both positive (e.g., companionship, validation,
intimacy) and negative (e.g., conflict frequency) aspects of the relationship. The
Network of Relationships Inventory (NRI; Furman & Buhrmester, 1985, 1992) is
typically administered to adolescents to assess the positive and negative dimen-
sions of friendship quality. Notably, one criticism of these measures is their limited
assessment of negative friendship features. In response, Furman and Buhrmester
developed a new version of the NRI, the Relationship Qualities Version (NRI-
RQV; Furman & Buhrmester, 2009). This revised measure includes a more diverse
range of negative features, including conflict, criticism, dominance, exclusion, and
pressure.
Consequences Associated
With Friendship Experiences
Given the important functions that friendships can serve in supporting the well-
being of children and adolescents, it is not surprising that those who do not have
friends, or who have poor quality friendship experiences, are vulnerable to a vari-
ety of negative outcomes. Researchers have examined the ways in which friend-
ship experiences relate to many aspects of socioemotional adjustment, including