Intergroup threat and affective polarization in a multi-party system

What explains affective polarization among voters and societal groups? Much of the existing literature focusing on mass political polarization in modern democracies originates in the US, where studies have shown that, while ideological separation has grown, political conflict increasingly reflects social identity divisions rather than policy disagreements, resulting in affective polarization. We focus on explaining such polarization in a multi-party context. Drawing on social identity theory and intergroup threat theory, we hypothesize that individuals who perceive an intergroup threat show stronger intergroup differentiation and increased affective polarization. We analyze the influence of perceived threat on affective polarization drawing on two large-scale representative surveys in Sweden (N = 1429 and 1343). We show that individual-level affective polarization is related to perceived intergroup threats among the voters in both studies, measuring affective polarization using social distance, negative trait attribution, and party like-dislike ratings.