How smartphone use becomes problematic: Application of the ALT-SR model to study the predicting role of personality traits

Smartphones have become a ubiquitous part of adolescents' life, and studies have repeatedly revealed a positive association between smartphone use (SU) and problematic smartphone use (PSU). However, longitudinal research investigating the reciprocal relationship among SU and PSU during adolescence are scarce, and studies that take into consideration personality traits as predisposing factors are lacking. This study used survey data collected annually over four years from 855 adolescents aged 11 at time 1 and distributed across 37 Swiss middle schools. An Autoregressive Latent Trajectory Model with Structured Residuals (ALT-SR model) was used to investigate between- and within-person effects over time. Additionally, gender and personality traits, measured according to the recently developed DSM-5 domains, were entered as predictors of the latent intercepts and slopes. The final model showed that, at the within-person level, SU significantly increased PSU at all four time points, but not viceversa. At the between-person level, the personality traits antagonism and negative affect significantly and positively predicted the latent intercepts, whereas being female, psychoticism, and disinhibition significantly and positively influenced the latent slopes. This study highlights the importance of investigating predisposing factors of PSU in adolescence, using advance statistical approaches. The results are discussed against the background of the I-PACE model on predisposing factors and mechanisms that lead to addictive behaviors such as PSU.