Habitual social media and smartphone use are linked to task delay for some, but not all, adolescents

There is a popular concern that adolescents’ social media use, especially via smartphones, leads to the delay of intended, potentially more important tasks. Automatic social media use and frequent phone checking may especially contribute to task delay. Prior research has investigated this hypothesis through between-person associations. We advance the literature by additionally examining within-person and person-specific associations of automatic social media use and mobile phone checking frequency with each other and task delay. Preregistered hypotheses were tested with multilevel modeling on data from 3 weeks of experience sampling among N = 312 adolescents (ages 13–15), including T = 22,809 assessments. More automatic social media use and more frequent phone checking were, on average, associated with more task delay at the within-person level. However, heterogeneity analyses found these positive associations to be significant for only a minority of adolescents. We discuss implications for the media habit concept and adolescents’ self-regulation.