Resumen de Longitudinal Associations Between Perceived Inclusivity Norms and Opinion Polarization in Adolescence

Maor Shani, Marjorie Berns, Lucy Bergen, Stefanie Richters, Kristina Krämer, Sophie de Lede, Maarten van Zalk

• Affective polarization, characterized by emotional hostility and behavioral avoidance toward ideological opponents beyond mere policy disagreements, can pose a significant threat to social cohesion. However, this phenomenon remains relatively unexplored in adolescence. This longitudinal study investigates whether perceived inclusivity norms—emphasizing equality‐based respect, open and constructive dialogue, and communal unity—reduce opinion‐based affective polarization among adolescents. Using a sample of 839 students from two demographically distinct German secondary schools (grades 7–11), we developed and validated measures of polarization tailored to adolescents, capturing dialogue orientation and social distance toward ideological outgroups. Results revealed stable ideological subgroup differences in norms and attitudes, with conservative students exhibiting lower descriptive and prescriptive inclusivity norms and higher affective polarization compared to their liberal peers. However, a significant proportion of adolescents demonstrated fluid political orientations over time, highlighting the malleability of early political identities. Cross‐lagged analyses showed no evidence that inclusivity norms directly reduce affective polarization, although early dialogue orientation significantly predicted greater social openness in diverse settings. Our findings advance the understanding of adolescent political identity development by demonstrating that while ideological orientations remain unstable during this period, group‐based differences in norm perceptions and polarization tendencies are already evident. We emphasize how this developmental fluidity presents both opportunities and challenges for interventions, suggesting that effective depolarization strategies must account for the distinct characteristics of adolescent political socialization and the varying influence of school‐based normative contexts.