Do Enlargements Make the European Union Less Cohesive? An Analysis of Trust between EU Nationalities*

This article analyses the impact enlargements have had on the social cohesion of the European Union (EU), measured as generalized interpersonal trust between EU nationalities. Based on a quantitative‐dyadic approach, Eurobarometer surveys from 1976 to 1997 are utilized. The key result is that enlargements do not necessarily weaken cohesion, but southern enlargement and the recent eastern enlargement did. The integrative effect of enlargement depends on the extent to which acceding nations differ from existing club members in three main dimensions: the level of modernization (mechanisms: prestige), cultural characteristics (mechanisms: similarity) and their power in the international system (mechanisms: perceived threat).