Developmental trajectories of adolescent problematic mobile phone use and their longitudinal associations with intolerance of uncertainty and distress tolerance: The moderating role of early‐life environmental unpredictability

The co-development of intolerance of uncertainty (IU) and distress tolerance (DT) and adolescent problematic mobile phone use (PMPU) and their relationships at both the between- and within-person levels remain poorly understood, particularly among Chinese adolescents navigating the highly stressful pre-college entrance examination period in East Asia. Further, the potential moderating effects of early-life environmental unpredictability (EEU) on these relationships are yet to be tested. This large-sample Chinese cohort study seeks to address these gaps through a three-wave design. A total of 4548 Chinese high school students (50.70% female; M_age = 16.87, SD = 0.81) were surveyed at baseline. The study employed latent growth curve modeling (LGCM) and the random intercept cross-lagged panel model (RI-CLPM). Univariate LGCMs identified an average continuous decline in PMPU among all adolescents. Parallel LGCMs indicated that individuals with higher PMPU levels also tended to report greater IU and DT (between-person effects). The results of the RI-CLPM revealed that DT consistently predicted subsequent PMPU and IU, while PMPU also predicted DT and IU (within-person effects). Importantly, all these findings exhibited different patterns of differentiation across groups with varying levels of EEU. In summary, this study highlights the complex relationship among IU, DT, and adolescent PMPU, emphasizing the crucial moderating role of EEU in these dynamic associations.