The Psychology of Supranationalism: Its Ideological Correlates and Implications for EU Attitudes and post-Brexit Preferences

Existing research highlights the roles of group identities and concerns about mass migration in explaining attitudes towards the European Union (EU). However, studies have been largely silent on whether EU attitudes are also shaped by people's attitudes towards the principles and practices of supranational governance. This research provides a first test of the nature and role of supranational attitudes. We introduce a new measure of supranationalism and, in two studies using samples drawn from the British population, test the psychometric properties of the supranationalism scale. We then identify the socioideological correlates (right-wing authoritarianism and social dominance orientation) of supranationalism, along with its effects in predicting EU attitudes and post-Brexit preferences. Our core finding is that supranationalism predicts attitudes towards the EU over and above established factors such as national identity and immigrant threat. Our study thus shows the existence of supranational attitudes among individuals and the relevance of such attitudes to people's opinions about international organizations like the EU.