Revisiting the Proximal Dominance Assumption: Community Social Inclusion in an Ecological Analysis of Finnish Adolescent Mental Health

Background and Purpose: Adolescent mental health is shaped by multiple ecological contexts. However, ecological research has often assumed that proximal microsystems show stronger associations with mental health than broader environments. This proximal dominance assumption has rarely been tested within comprehensive models comparing multiple domains across different outcomes. This study assessed whether perceived community social inclusion shows associations with mental health beyond more proximal factors in a large Finnish sample. Methods: Data from the 2019 Finnish School Health Promotion Study were analyzed. Blockwise OLS regression models estimated incremental associations of five analytic domains (demographic background, individual, family, school and peer, and perceived community social inclusion) with depressive symptoms, anxiety symptoms, loneliness, and life satisfaction. Exploratory moderation analyses tested whether community social inclusion, school belonging, and parent-child relationship buffered associations between cognitive difficulties and outcomes. Results: Final analytic sample comprised 69,800 adolescents (mean age 15.54 years, 47.0% boys). Final models explained 41.3– 51.9% of variance. Cognitive difficulties showed the strongest associations with depression (β = 0.292) and anxiety (β = 0.375). Perceived community social inclusion showed the largest standardized association with life satisfaction (β = 0.446) and the largest negative association with depression (β = − 0.331), after adjustment for all other domains. Loneliness displayed unique sensitivity to school and peer factors. Moderation results indicated limited cross-level buffering, suggesting predominantly additive patterns. Conclusion: The findings challenge the proximal dominance assumption. Perceived community social inclusion showed substantial associations with key outcomes after full adjustment. Different mental health outcomes display distinct ecological profiles, consistent with the proposed Asymmetric Ecological Model, in which domain salience varies across outcomes rather than a uniform proximity hierarchy. The predominantly additive pattern suggests promotive pathways rather than buffering pathways. Approaches strengthening social inclusion may complement individual and family interventions, though the cross-sectional design precludes causal inference.