Selection and influence processes in academic achievement-More pronounced for girls?

Friends tend to be similar in their academic achievement. In this study, we investigate whether this similarity results from students selecting friends with similar achievement or from friends influencing students' achievement. In particular, we argue that selection and influence effects should be stronger among girls than among boys. Using friendship network data on 1273 German secondary school students and stochastic actor-oriented models for the co-evolution of networks and behavior, we find selection effects only among girls, which is in line with our theoretical arguments. By contrast, influence effects contribute to achievement similarity among both boys and girls.