Torcal, MarianoComellas Bonsfills, Josep Maria2025-10-212025-10-212025Torcal M, Comellas JM. Operationalizing affective polarization in multiparty systems. In: Torcal M, Harteveld E, editors. Handbook of affective polarization. Cheltenham, UK: Edward Elgar Publishing Ltd.; 2025. p. 69-87. DOI: 10.4337/9781035310609.000119781035310593http://hdl.handle.net/10230/71605This chapter delves into the complexities of measuring affective polarization (AP) in multiparty systems, extending research from the US to more diverse party settings. It highlights the challenges of adapting measures like the feeling thermometer to such contexts, where individuals may have nuanced feelings towards multiple parties. Existing indices like the affective polarization index (API) and weighted mean distance from the most-liked party (Distance) encounter difficulties in capturing the intricate dynamics of AP in multiparty systems. The chapter proposes a new measure that integrates Social Identity Theory (SIT) into the measurement of AP. This approach aims to capture genuine affective ties and hostilities, avoiding instrumental considerations. Preliminary validation of the new measure is conducted using survey data from Spain.application/pdfeng© The Editors and Contributors Severally 2025. This is an open access work distributed under the Creative Commons AttributionNonCommercial-NoDerivatives 4.0 International (https://creativecommons.org/licenses/by-nc-nd/4.0/) license.info:eu-repo/semantics/bookPart2025-10-21http://dx.doi.org/10.4337/9781035310609.00011Affective polarizationMeasurementMultiparty systemsThermometer feelingsinfo:eu-repo/semantics/openAccess