Application of the differential susceptibility to media effects model to comprehend emerging adults' problematic smartphone use: A one-year longitudinal study.

Considering the pervasive integration of smartphones into the daily lives and high prevalence of problematic smartphone phone use (PSU) among emerging adults, there is an urgency for an integrated perspective to understand their PSU for better intervention insights. This study aims to apply a multi-level theoretical framework, the Differential Susceptibility to Media Effects Model (DSMM), to PSU and evaluate not only the direct effects of dispositional (i.e., neuroticism), social (i.e., family adaptability), and developmental factors (i.e., inclusion of smartphone in the self [ISS]) on PSU but also the potential indirect effect of ISS. We obtained a sample of 801 Chinese emerging adults (559 females; Mage = 19.02 and SDage = 0.88) through a one-year longitudinal study with two surveys (at wave 1 [W1] and wave 2 [W2]). Hierarchical regression analysis indicated that all baseline susceptibility factors (neuroticism [W1], family adaptability [W1], and ISS [W1]) significantly predicted PSU (W2) after controlling for both demographics and PSU (W2). The results of structural equation modeling further suggested that neuroticism (W1) and family adaptability (W1) were longitudinally associated with ISS (W2), which was in turn associated with PSU (W2). This study provided not only longitudinal evidence to support the application of DSMM to explain PSU but also insights into interventions using targeted approaches.