Peer networks, body dissatisfaction and disordered eating in adolescent girls

"Major aetiological theories propose that friends and peers are a particularly important source of influence in the development and maintenance of body dissatisfaction and disordered eating during adolescence. Although a growing body of research suggests that the peer environment is associated with adolescent girls' weight-related attitudes and behaviours, the literature is limited by an over-reliance on cross-sectional methodologies and assessments of perceived (rather than actual) influence. Further, empirical studies have concentrated exclusively on peer socialisation effects, neglecting to investigate the possible role of peer selection processes. This thesis aimed to overcome these previous limitations by examining the contribution of friends and peers to adolescent girls' body dissatisfaction and disordered eating using a combination of longitudinal and experimental research designs. Three separate studies were conducted. The first used longitudinal structural equation modelling to investigate the interrelationships between perceived friend influence, body dissatisfaction and disordered eating. Specific mediational pathways proposed in aetiological models were tested in a large community sample of adolescent girls. The second study utilised sophisticated social networking analyses to examine the way in which friend selection and socialisation processes simultaneously contributed to body dissatisfaction and disordered eating over time. In this study, actual (peer-reported) attitudes and behaviours rather than adolescents' perceptions were used. The final study focused on the interaction between peer and media factors, using a novel experimental design to test whether peer norms influenced the way in which adolescent girls responded to thin-ideal images. The influence of less familiar peers, rather than friends, was examined in this study. Results showed that changes to adolescent girls' weight-related attitudes and behaviours were not predicted by either perceived or actual friend influences, however, body dissatisfaction and disordered eating were important in friend selection processes. In addition, younger adolescents were more likely to be influenced by peer norms in their response to thin-ideal images than older adolescents. These findings suggest that adolescents may not be as passive in being shaped by peer influences as previously thought, and highlight important developmental differences in susceptibility to peer influences. Together, the studies make a significant contribution to current understanding of how peers contribute to adolescent girls' body dissatisfaction and disordered eating and have important implications for prevention and intervention." -- Abstract.