How similar or different do citizens perceive in- and out-party supporters with regard to non-political traits in multi-party systems?

A growing body of literature in political psychology has shifted its focus on the growing alignment between citizens’ political and social identities. Indeed, recent studies find that, in bipartisan and multiparty political systems alike, left- and right-leaning voters tend to reside in different types of areas, hold different types of occupation, drive different types of cars, drink their coffee in different ways, and have different tastes in music and art. Furthermore, this phenomenon is usually linked in existing research with the different attitudes or behaviors that some citizens hold towards (political) others such as the rising levels of ideological and affective polarization in western democracies. In this paper we argue that citizens’ perceptions of these non-political differences or similarities, particularly in relation to their party identification, are crucial for our understanding of their attitudes towards ingroup and outgroup supporters, but research on these are still lacking. To fill this gap, we present the novel concept of perceptions of differentness/similarity (PoDS) which we define as “citizens’ perceptions that politically other- or like-minded citizens are different and/or similar from themselves with regard to attributes that are not obviously political in nature.” Firstly, we draw from a quantitative content analysis conducted on approximately 6,000 responses to an online survey by citizens of Belgium and uncover four broad categories of non-political attributes that citizens most often use to describe other voters: their socio-economic position, personality, lifestyle, and norms and values. Secondly, using a representative sample of Belgian citizens (approx. 5000 respondents), we show the extent to which citizens perceive in-party supporters as similar to themselves, and out-party supporters as different from themselves, with regard to these four categories. Moreover, we intend to examine whether these perceptions of differentness/similarity are contingent on citizens' level of party identification.