Background: Research on well-being inequalities has typically examined the independent effects of social positions, often overlooking how the interplay of multiple social categorizations can shape well-being outcomes. This study explored how multiple social positions based on gender, age, immigrant background, family structure, and perceived family socioeconomic status shape patterns of inequality in three well-being outcomes—psychosomatic complaints, mental well-being, and problematic social media use—among Nordic adolescents.

Methods: Data from the Health Behaviour in School-aged Children Study, collected in four Nordic countries (Finland, Iceland, Norway, and Sweden) in 2022 (N = 22 366, ages 9–19), were analyzed using the Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) approach. Participants were nested within 168 strata defined by their multiple social positions.

Results: Of the additive contributions of individual social positions, female gender was most strongly associated with poorer well-being across all outcomes. Interaction effects indicating more favorable well-being than expected based on additive main effects were identified across all outcomes for non-immigrant girls aged 9 to 12 perceiving high family socioeconomic status. Unexpectedly, non-immigrant boys aged 15 years and older from nuclear families with low perceived family socioeconomic status reported better well-being levels than anticipated. In contrast, interaction effects demonstrating less favorable well-being were observed for older, non-immigrant girls from nuclear families with high perceived family socioeconomic status, who reported poorer outcomes than expected. Several other subgroups also displayed significant deviations from anticipated outcomes in specific well-being domains.

Conclusions: The findings reveal significant intersectional disparities in well-being, notably in psychosomatic complaints and problematic social media use. The same social positions can form different patterns of advantage and disadvantage for individuals across different subgroups.