Potential Mechanisms of Peer Influence on Adolescent Girls' Disordered Eating Behavior: An Experimental Design

This study used an experimental paradigm to examine two factors that may influence the socialization process of peer influence on adolescent females' vulnerability to engage in disordered eating behavior: body-related social comparison and desire to emulate a popular prototype. In the first phase of this study, data were collected to establish local body and dieting norms, as well as to construct study manipulations. In the second phase of the study, subjects participating in the experimental portion were randomly assigned to one of three experimental conditions in which they were exposed to maladpative eating norms by ostensible female peers who were either: (1) thin and of popular peer status; (2) thin and of average peer status; or (3) heavy and of average peer status. Hypotheses were partially supported. Differences emerged in response patterns between 9th and 10th grade participants. Ninth grade participants generally experienced peer influence of disordered eating behaviors. Tenth grade participants, however, did not appear to experience peer influence of disordered eating behaviors. An interaction between body mass index (BMI) and grade was observed such that 9th graders with lower BMI responded significantly more maldaptively in the experimental condition than 10th graders with lower BMI. Results suggest body size was most salient to 9th grade participants' peer influence vulnerability. Peer-led interventions may be particularly effective, but should be tailored to norms within the specific peer context.