Smartphone addiction and internalized and externalized aggression among adolescents: Evidence from longitudinal study and weekly diary study

Smartphone addiction is a global issue, especially among adolescents and it is closely tied to problematic behaviors, including aggression. However, the dynamic association and underlying mechanisms between smartphone addiction and aggression have rarely been explored by previous studies. Based on emotion regulation theory and the frustration-aggression hypothesis, the study examined the relationship between smartphone addiction, depression and internalized/externalized aggression. Study 1 adopted a longitudinal design at the trait level and Study 2 utilized a weekly diary at the state level to examine the associations between these variables. Study 1 revealed that smartphone addiction at time point 1 (T1) did not significantly predict internalized or externalized aggression at time point 2 (T2). Study 2 indicated that smartphone addiction in the previous week could predict internalized/externalized aggression in the following week. Additionally, Study 1 and Study 2 both showed that depression has indirect an effect on the relationship between smartphone addiction and internalized aggression, but not on smartphone addiction and externalized aggression. These findings not only enhance our comprehension of the underlying connections between smartphone addiction and internalized/externalized aggression but also offer valuable theoretical insights for developing future prevention and intervention measures aimed at addressing problematic behavior among adolescents.