Political identity bias in interpersonal attitudes: Explaining affective polarisation in the 2023 Spanish general election

Abstract

Introduction: This paper aims to test which has a greater influence on affective polarisation (AP) in a multi-party system such as the Spanish one: partisan identity or ideology. In doing so, we review the validity of the expressive approach to partisanship and we test the biases that political identities can cause. Method: We use a strict measure based on a feeling thermometer regarding ordinary people depending on the party they vote for and their ideology and we pro-pose a formula to estimate the levels of difference in interpersonal political affect (DIPA). Subsequently, linear regression models were developed using data from a national representative sample survey conducted during the election campaign for the July 2023 general elections (n = 1,223). Results: Strong positive partisanship influences individual AP in a prominent way both when attitudes are expressed towards partisan or ideological groups. This contradicts the widespread discourse regarding the primacy of ideology in European multiparty systems. Moreover, we show that the overlapping between the-se two identities is not significant in explaining the phenomenon. Conclusion: AP is a group identity-based phenomenon even outside the U.S, which invites us to interpret it using the theories of social psychology.