Triggers and Hierarchies of Social Identities in the European Parliament

Research on dynamics within the European Parliament frequently draws on group‐based explanations – such as parties and national affiliations – for the behaviour of its members. Hence, there is a growing interest in the question of how policy issues trigger the salience of group memberships and whether partisan or national group memberships – and which of them – rank higher when voting on issues. This article provides answers to these questions by presenting empirical evidence on the group memberships that are decisive for the voting behaviour of Members of the European Parliament (MEPs). In theoretical terms, it introduces the social‐psychological perspective on social identities to European Union (EU) parliamentary research. Methodologically, the article relies on a qualitative comparative analysis of voting results in three resolutions of the 9th EU legislative term. The findings emphasize a hierarchy of salient social identities and reveal that some national and some partisan identities are stronger than others in the European Parliament.