Validating the Feeling Thermometer as a Measure of Partisan Affect in Multi-Party Systems

Affective polarization is increasingly studied in multi-party systems, and virtually all studies that do so operationalize it using the feeling thermometer. Yet usage of this survey instrument originates in the American two-party system, and there are reasons to suspect whether it captures partisan affect similarly elsewhere. We argue that for the feeling thermometer to be a valid measure of partisan affective evaluations also in multiparty systems, it needs to capture sentiment towards partisans, and to fluctuate over time and across parties in sync with other established measures of affective polarization. Using a seven-wave panel study fielded throughout Israel’s three elections in 2019-2020, we show that both requirements strongly hold. We use automated text analysis to substantiate that thermometer scores reflect sentiment towards party supporters, and demonstrate that they go hand-in-hand with preferences for partisan social distance and discrimination in economic games. We discuss implications for the study of comparative affective polarization.