This study examined the cross-sectional and prospective relationships between three sources of school-related social support (parent involvement, peer support for learning, and teacher-student relationships) and early adolescents' global life satisfaction. The participants were 597 middle school students from 1 large school in the southeastern United States who completed measures of school social climate and life satisfaction on 2 occasions, 5 months apart. The results revealed that school-related experiences in terms of social support for learning contributed substantial amounts of variance to individual differences in adolescents' satisfaction with their lives as a whole. Cross-sectional multiple regression analyses of the differential contributions of the sources of support demonstrated that family and peer support for learning contributed statistically significant, unique variance to global life satisfaction reports. Prospective multiple regression analyses demonstrated that only family support for learning continued to contribute statistically significant, unique variance to the global life satisfaction reports at Time 2. The results suggest that school-related experiences, especially family-school interactions, spill over into adolescents' overall evaluations of their lives at a time when direct parental involvement in schooling and adolescents' global life satisfaction are generally declining. Recommendations for future research and educational policies and practices are discussed.

Introduction: Experiencing elevated stress increases the risk of further difficulties in mental health, including externalizing behaviors in adolescents. There is a need for understanding the factors that help adolescents mitigate social stress to prevent problematic externalizing behaviors. Growth mindset has been found to be a promising protective factor in adolescent development including mental health. This study aimed to examine the potential buffering role of growth mindset of thoughts‐emotion‐and‐behaviors in the context of two types of social stress (i.e., family and peer) to reduce externalizing behaviors among adolescents.Methods: The sample is composed of 399 adolescents (age range 14–18 years, M = 16.22, SD = 1.21; 56.4% female, 42.3% male, 1.3% gender‐nonconforming or variant) from a large, urban, diverse high school in the United States. Adolescent self‐reports were administered at one time.Results: Moderation analyses revealed that growth mindset of thoughts, emotion, and behaviors moderate the association between family stress and externalizing behaviors. The magnitude of this association weakened as the level of growth mindset increased, supporting the buffering effect of the moderator. Neither the moderation effect of growth mindset nor the main effects of peer stress and growth mindset were significant in predicting externalizing behaviors.Conclusion: Taken together, the findings suggested that growth mindset has protective effects in reducing externalizing behaviors when adolescents experience family stress. Future directions and implications are discussed.