Hyeonho Hahm, David Hilpert, Thomas König
Divided We Unite: The Nature of Partyism and the Role of Coalition Partnership in Europe

American Political Science Review, 2024: 118, issue 1, pp. 69-87
ISSN: 0003-0554 (print), 1537-5943 (online)

Highlighting the strength of “partyism” in many democracies, recent scholarship pays keen attention to increasing hostility and distrust among citizens across party lines, known as affective polarization. By combining a conjoint analysis with decision-making games such as dictator and trust games, we design a novel survey experiment to systematically estimate and compare the strength of the partisan divide relative to other social divides across 25 European democracies. This design also allows us to investigate how the two components of affective polarization, in-group favoritism and out-group derogation, are moderated by the way parties interact with each other. We first find dominance of the partisan divide compared to other social divides that constitute traditional cleavages such as social class and religion. Second, we show that affective polarization in Europe is not primarily driven by out-group animus. Finally, we demonstrate that coalition partnership lessens affective polarization by reducing both in-group and out-group biases.