Practice makes perfect: The longitudinal effect of adolescents’ instant messaging on their ability to initiate offline friendships

•We focus on the influence of online communication on offline social competence.•We investigate whether instant messaging influences offline friendship initiation.•Instant messaging increased adolescents’ ability to initiate friendships over time.•This effect occurred through the diversity of their online communication partners.•Such practice of social skills with diverse people may increase social competence. The first aim of this study was to investigate whether instant messaging (IM) influences adolescents’ ability to initiate offline friendships. The second aim was to study the validity of two underlying mechanisms that may account for this relationship: (a) the opportunities offered by IM to communicate with a variety of people, and (b) to disclose intimate information. A three-wave longitudinal study was conducted among 690 Dutch adolescents (10–17years old). Results show that adolescents’ IM use increased their ability to initiate offline friendships over time. Furthermore, IM use indirectly increased adolescents’ ability to initiate offline friendships through the diversity of their online communication partners. These findings suggest that adolescents can practice social skills online and learn to relate to a variety of people, which, over time, may increase their ability to initiate offline friendships.