Muslim religiosity is often portrayed as a barrier to integration into secular societies, especially in Europe. Scholars suggest that religiously segregated networks reinforce Muslims’ religiosity and religious identification, but solid evidence is scarce. Based on longitudinal German data, we examined whether friendship networks influence Muslim youths’ religiosity. Using stochastic actor-oriented models, we also assessed whether religiosity in turn relates to friendship choices. We found that higher shares of Muslim friends neither increase Muslim youths’ religious identification nor their frequency of prayer, but they are associated with more frequent mosque attendance. Furthermore, Muslim youths assimilated their Muslim friends’ mosque attendance and frequency of prayer. Friends’ actual religious practices, rather than shared group membership, thus seems to shape individual religiosity. Finally, religiosity does not hamper interreligious friendships; it was unrelated to friendship choices. Results are similar for Christian youths, suggesting that these patterns are not unique to Muslims.
