Many political systems are becoming increasingly polarized and several scholars have suggested that the deep partisan divisions in society derive not simply from ideological policy disagreement but from social-identity conflicts (Mason, 2013; 2018), suggesting a so called affective polarization, in which political opponents are seen as a disliked outgroup (Iyengar et al., 2012; 2019). Scholars are increasingly interested in the topic of polarization among political elites, particularly in the context of the deepening divisions in the US Congress (McCarty et al., 2016). In European multiparty systems, we know much less about polarization among political elites, especially polarization in terms of identity conflict. The aim of this paper is therefore to examine affective polarization at the elite level in Europe. We focus on the relationship between the backgrounds of members of parliament (MPs) and affective polarization in parliament, and investigate whether MPs with a specific background are ‘driving’ affective polarization. We argue that how distinct MPs from the same party are in terms of their backgrounds compared to MPs from other parties should matter for how polarized they are. Based on social identity theory, we expect that MPs with fewer overlapping social identities with MPs from other parties are more likely to be affectively polarized, since in- and out-group distinctions are likely to be clearer in these instances. We evaluate our expectations using data on Norwegian and Swedish MPs and a computational method for content analysis to analyze the emotional content of their parliamentary speeches since the early 1990s until today.