This study aimed to identify how school climate shapes adolescent wellbeing, and the extent to which social–emotional characteristics (SECs) explain these associations, using nationally representative data from New Zealand secondary schools (N = 3,575 students; 168 schools) in the 2022 Programme for International Student Assessment (PISA) linked with school-level administrative indicators. A two-level multilevel structural equation model (MSEM) was estimated to examine direct and indirect relations between five dimensions of school climate, seven SECs, and two wellbeing outcomes (life satisfaction and psychosomatic symptoms), while accounting for student- and school-level demographics. At the within-school level, more positive relational and belonging-focused climates were associated with higher SECs and better wellbeing, whereas greater exposure to bullying and school risk was linked to poorer emotional regulation and elevated psychosomatic symptoms. SECs—particularly stress resistance and emotional control—partially mediated the associations between school climate and wellbeing, indicating that socio–emotional functioning is a key mechanism linking school experiences to students’ subjective wellbeing. At the between-school level, school gender composition, size, and geographic context showed modest associations with average wellbeing, whereas school socioeconomic composition was not uniquely related once other contextual factors were considered. Overall, the findings underscore the central role of relationally supportive and emotionally safe school environments, and of SECs, in promoting adolescent wellbeing.
Sotardi et al. (Sat,) studied this question.