Abstract
This study examined the heterogeneity in positivity trajectories and the predictive roles of family and school environments (i.e., perceived parental warmth and basic psychological need satisfactions at school) from mid-childhood to early adolescence. Elementary school students in China (N = 2204, 54.9% boys, M
age = 9.47 years) completed relevant measures on six occasions, every 6 months. Latent class growth modeling revealed four heterogeneous developmental trajectories of positivity: High-Increasing (50.6%), Moderate Low-Increasing (33.2%), Low-Stable (11.0%), and High-Decreasing (5.2%). Perceived parental warmth and satisfaction of relatedness and competence needs at school significantly predicted trajectory class membership. Findings underscore the value of identifying group difference in positivity development in youth and the need for specific interventions targeting their unique characteristics.