Conflict, Contact, and Collegia

For decades, researchers in various disciplines have studied correlations between migration and social capital, namely, the impact of diversity on neighbour trust and community cohesion. Yet, so far, ancient historians have treated the topics of migration and social capital separately. The present article introduces the relevant empirical studies and social theories from other disciplines. It then applies findings from this modern research to Roman neighbourhoods. One outcome is a new perspective on the role of collegia in fostering or corroding trust and social capital in urban neighbourhoods: some associations can be understood as ‘bridging’ in that they generated intergroup contact and so social capital, while others (probably most) were a force of division in that they proliferated out-groups and fostered distrust among neighbours. The collegia of port societies and other diverse neighbourhoods such as Regio XIV Transtiberim are more likely to have enhanced social capital in their locales than are the associations of more homogeneous and inland societies.