Several studies have highlighted the critical importance of friendship in human development (Goldstein, Field, & Healy, 1989; Greenberg, Siegel, & Leitch, 1983). A recent review of the literature on friendship revealed that children with close friends showed better academic performance, were less likely to drop out of school, and had lower rates of juvenile delinquency and adult psychopathology (Parker & Asher, 1987). Another review emphasized that the DSM-III-R uses lack of close peer relationships as a criterion for a number of psychiatric disorders of childhood (Reisman, 1985).
Intimate friendship seems to be one of the most salient characteristics of adolescence, more so than in previous developmental stages (Buhrmester, 1990). A study that compared preadolescents with adolescents found that intimate friendship is more important to adolescents (Buhrmester, 1990). The study also noted that competence in peer relationship skills is a greater concern for adolescents than for preadolescents.
The present study examined the interactions of adolescent best friend pairs in the same manner as a study by Field, Greenwald, Morrow, Healy, Foster, Guthertz, and Frost (1992) on preadolescents. In that research preadolescent best friends, as compared with acquaintances, showed more matching of positive behavioral states and lower stress as evidenced by lower cortisol levels. The present study used the same paradigm to determine whether adolescent best friend pairs show similar matching of behavior states during interactions and whether there are differences across same-sex and opposite-sex interactions at a time when opposite-sex friendships are developing. The opposite-sex friendship assessment was new to this study.
Few studies have compared same-sex friendships with opposite-sex friendships in adolescents. A discontinuity in opposite-sex friendship might be expected because of the erotic element (Sharbany, Gershoni, & Hoffman, 1981). Opposite-sex friendship is considered a learning stage for mature sexual relations and has been considered a more intimate form of friendship than same-sex friendship in adolescence (Sharbany et al., 1981). However, because of the relative novelty, opposite-sex interactions may not be as relaxed.
Questions addressed in this study were whether personality characteristics, such as self-esteem and extraversion, would be important factors in opposite-sex friendships versus same-sex friendships. Would opposite-sex friends be more matched in their behavior states than would same-sex friends, or would they be less matched because high school juniors have less experience with opposite-sex friends? Opposite-sex friends might engage in more polite turn-taking rather than being in similar behavior states of animation and playfulness. Also, cortisol levels may be higher in opposite-sex friends than in same-sex friends because the erotic element may elicit more stress during the interaction (Sharbany et al., 1981).
To examine these questions, adolescents were videotaped in samesex and opposite-sex best friend pairs during a conversation on any topic. The videotapes were later rated for concordance of behavior states. In addition, saliva samples were collected to determine the subjects' cortisol levels before and after the interaction. The subjects also completed questionnaires in which they rated their interaction and the likability and characteristics of their partner. They were also asked to complete self-esteem, peer intimacy, depression, and anxiety scales.
Subjects and Procedure
Forty-eight high school juniors (24 males and 24 females) were asked to participate in the study and to name their best same-sex friend and best opposite-sex friend who attended the same high school. Their best friends were then invited to participate with them. The average age of the adolescents was 16.3 years (range = 15-17). Their ethnic distribution was 35% Hispanic, 33% white, 18% African American, and 14% other, consistent with the high school distribution. …