Predicting adolescent eating and activity behaviors: The role of social norms and personal agency.

Guided by the theory of planned behavior, this 2-week longitudinal study examined health behaviors in a sample of 279 adolescents. Social norms and perceived behavioral control (PBC) were tested as predictors of self-reported intentions and behaviors in 2 domains, eating and physical activity. Differentiating, as opposed to aggregating, parent and peer norms provided unique information. For PBC, the authors distinguished global causality beliefs from self-related agency beliefs and intraself (effort, ability) from extraself (parents, teachers) means. Intraself agency beliefs strongly predicted healthy intentions, whereas intraself causality beliefs had a negative influence. Patterns differed somewhat across behaviors and gender. Results highlight theoretical issues and provide potential targets for research on health promotion programs for youth. (PsycINFO Database Record (c) 2010 APA, all rights reserved)