The hypothesized mediation model. Extracurricular participation status refers to one of two activity domains (i.e., sports and performance arts or clubs) in grade 8. Separate analyses were conducted for each of four grade 9 outcome variables: competence beliefs, education value, behavioral engagement, and course grades. All analyses controlled for the baseline measures of perceived friends’ prosocial norms in grade 6 and baseline measure of the outcome variables in grade 5. For the sports model only, grade 5 highest parent education level was a covariate for perceived friends’ prosocial norms and all outcomes. G5, G6, and G8 are grade 5, 6, and 8, respectfully.