The Interaction of Chronotype and Sleep Duration in the Association Between Smartphone Usage Time and Problematic...

This study examined whether the interaction between chronotype and sleep duration moderates the relationship between smartphone usage time and problematic smartphone use (PSU) among early adolescents.

A cross-sectional secondary analysis was conducted using nationally representative data from the 2018 Korean Children and Youth Panel Survey (N = 3,919; 4th and 7th graders). Chronotype, sleep duration, smartphone use, and PSU were assessed. Moderation and moderated moderation analyses were conducted using PROCESS Macro models, controlling for personal, familial, school, and community covariates.

This study demonstrated that chronotype and sleep duration interacted to moderate the association between smartphone use and problematic smartphone use (PSU) in early adolescents. Short sleep duration strengthened the positive association between smartphone use and PSU in both advanced and delayed chronotypes. By contrast, with longer sleep duration, this association shifted to a negative correlation, particularly in advanced chronotypes.

These findings suggest that both sleep duration and chronotype may play important roles in the association between smartphone use and PSU in early adolescence. Parental and school-based programs that encourage healthy sleep and smartphone use habits could be promising avenues for intervention. Longitudinal research is needed to further investigate the directionality and mechanisms of these associations.