Simulating downward spirals of interethnic hostility in empirical school networks

As ethnic diversity increases in Western countries, concerns about negative outgroup attitudes and interethnic polarization are growing. In diverse classrooms, processes such as peer influence and homophilic friend selection contribute to changing outgroup attitudes. This study explores if and when individual attitude shifts driven by these processes might scale up to intergroup hostility in empirical multiethnic school cohorts that initially have a rather positive interethnic climate. Using an agent-based model calibrated with longitudinal network and attitude data, we conduct a series of computational experiments to assess the effects of hypothetical macro-level shocks, such as violent incidents where a minority group is associated with the perpetrators. Our findings indicate that correlational peer influence on attitudes towards Turks, when pushed to extreme parameter values, can over time magnify even small outgroup biases, leading to interethnic hostility. This dynamic is accelerated under strong ethnic homophily. We further provide a detailed analysis of how these results emerge from the empirical context and the interacting processes modeled.