Editing Political polarization (section)

==Definitions and measurements==

Polarization itself is typically understood as "a prominent division or conflict that forms between major groups in a society or political system and that is marked by the clustering and radicalisation of views and beliefs at two distant and antagonistic poles." as defined by the [[Institute for Integrated Transitions]] and [[Ford Foundation]].<ref>{{Cite web |title=Closing the Divide: Inside Our Global Initiative on Polarization |url=https://www.fordfoundation.org/work/learning/learning-reflections/closing-the-divide-inside-our-global-initiative-on-polarization/ |access-date=2024-06-10 |website=Ford Foundation |date=29 May 2024 |language=en-US}}</ref>

Political scientists typically distinguish between two levels of political polarization: elite and mass. "Elite polarization" focuses on the polarization of the political elites, like [[party organizer]]s and [[elected officials]]. "Mass polarization" (or popular polarization) focuses on the polarization of the masses, most often the electorate or general public.<ref name="mccarty-06">{{cite book|url=https://archive.org/details/polarizedamerica0037mcca/page/|title=Polarized America : the dance of ideology and unequal riches|last=McCarty|first=Nolan|author2=Poole, Keith T.|author3=Rosenthal, Howard|publisher=MIT Press|year=2006|isbn=978-0262134644|at=[https://archive.org/details/polarizedamerica0037mcca/page/ Cambridge, Mass.]}}</ref><ref name="hetherington-09">{{cite journal|last=Hetherington|first=Marc J.|title=Review Article: Putting Polarization in Perspective|journal=British Journal of Political Science|date=17 February 2009|volume=39|issue=2|page=413|doi=10.1017/S0007123408000501}}</ref><ref name="layman-06">{{cite journal|author1-link=Geoffrey Layman|last=Layman|first=Geoffrey C.|author2-link=Thomas M. Carsey|author2=Carsey, Thomas M. |author3=Horowitz, Juliana Menasce |title=Party Polarization in American Politics: Characteristics, Causes, and Consequences|journal=Annual Review of Political Science|date=1 June 2006|volume=9|issue=1|pages=83–110|doi=10.1146/annurev.polisci.9.070204.105138|doi-access=free}}</ref><ref name="carmines-12">{{cite journal|last=Carmines|first=E. G.|author2=Ensley, M.J. |author3=Wagner, M.W. |title=Who Fits the Left–Right Divide? Partisan Polarization in the American Electorate|journal=American Behavioral Scientist|date=23 October 2012|volume=56|issue=12|pages=1631–1653|doi=10.1177/0002764212463353|s2cid=147108446}}</ref>

===Elite polarization===

[[File:NOMINATE polarization.jpg|thumb|Political polarization in the United States House of Representatives (DW-Nominate scores){{Update needed|date=July 2024}}]]
Elite polarization refers to polarization between the party-in-government and the party-in-opposition.<ref name=baldassarri-08/> Polarized political parties are internally cohesive, unified, programmatic, and ideologically distinct; they are typically found in a [[parliamentary system]] of democratic governance.<ref name="mann-12">{{cite book|url=https://books.google.com/books?id=CQORs1_S2sgC|title=It's Even Worse Than It Looks: How the American constitutional system collided with the new politics of extremism|last=Mann|first=Thomas E.|author2=Ornstein, Norman J.|publisher=[[Basic Books]]|year=2012|isbn=978-0465031337|archive-url=https://web.archive.org/web/20140705154533/http://books.google.com/books?id=CQORs1_S2sgC&printsec=frontcover|archive-date=2014-07-05|url-status=dead}}</ref><ref name=mccarty-06/><ref name=layman-06/><ref name=carmines-12/>

In a [[two-party system]], a polarized [[legislature]] has two important characteristics: first, there is little-to-no ideological overlap between members of the two parties; and second, almost all conflict over legislation and policies is split across a broad ideological divide. This leads to a conflation of political parties and ideologies (i.e., Democrat and Republican become nearly perfect synonyms for liberal and conservative) and the collapse of an ideological center.<ref name="mann-12" /><ref name="mccarty-06" /><ref name="layman-06" /><ref name="carmines-12" /> However, using a cross-national design that covers 25 European countries, a recent study shows that it is not the number of parties itself, but the way a party interreacts with another that influences the magnitude and nature of affective polarization.<ref name="doi.org">{{Cite journal |last1=Hahm |first1=Hyeonho |last2=Hilpert |first2=David |last3=König |first3=Thomas |date=2022-11-07 |title=Divided by Europe: affective polarisation in the context of European elections |url=https://doi.org/10.1080/01402382.2022.2133277 |journal=West European Politics |volume=46 |issue=4 |pages=705–731 |doi=10.1080/01402382.2022.2133277 |s2cid=253432411 |issn=0140-2382}}</ref>

The vast majority of studies on elite polarization focus on legislative and deliberative bodies. For many years, political scientists measured polarization in the US by examining the ratings of party members published by interest groups, but now, most analyze [[recorded vote|roll-call voting]] patterns to investigate trends in party-line voting and party unity.<ref name="fiorina-08" /><ref name="mccarty-06" /> Gentzkow, Shapiro, and Taddy used the text of the Congressional Record to document differences in speech patterns between Republicans and Democrats as a measure of polarization, finding a dramatic increase in polarized speech patterns starting in 1994.<ref>Gentzkow, Matthew, and Shapiro, Jesse, and Taddy, Matt [https://web.stanford.edu/~gentzkow/research/politext.pdf Measuring Polarization in High-Dimensional Data: Method and Application to Congressional Speech]"</ref>

=== Mass polarization ===
Mass polarization, or popular polarization, occurs when an electorate's attitudes towards political issues, policies, celebrated figures, or other citizens are neatly divided along party lines.<ref name="mccarty-06" /><ref name="layman-06" /><ref name="carmines-12" /><ref name="claassen-08">{{cite journal|last=Claassen|first=R.L.|author2=Highton, B.|date=9 September 2008|title=Policy Polarization among Party Elites and the Significance of Political Awareness in the Mass Public|journal=Political Research Quarterly|volume=62|issue=3|pages=538–551|doi=10.1177/1065912908322415|s2cid=154392221}}</ref> At the extreme, each camp questions the moral legitimacy of the other, viewing the opposing camp and its policies as an existential threat to their way of life or the nation as a whole.<ref>{{Cite web|date=2016-06-22|title=Partisanship and Political Animosity in 2016|url=https://www.people-press.org/2016/06/22/partisanship-and-political-animosity-in-2016/|access-date=2019-10-26|website=Pew Research Center for the People and the Press}}</ref><ref>{{Cite journal|last1=García-Guadilla|first1=María Pilar|last2=Mallen|first2=Ana|date=2019-01-01|title=Polarization, Participatory Democracy, and Democratic Erosion in Venezuela's Twenty-First Century Socialism|journal=The Annals of the American Academy of Political and Social Science|volume=681|issue=1|pages=62–77|doi=10.1177/0002716218817733|issn=0002-7162|doi-access=free|s2cid=149617060}}</ref>

There are multiple types or measures of mass polarization. ''Ideological polarization'' refers to the extent to which the electorate has divergent beliefs on ideological issues (e.g., abortion or affirmative action) or beliefs that are consistently conservative or liberal across a range of issues (e.g., having a conservative position on both abortion and affirmative action even if those positions are not "extreme").<ref>{{Cite journal|last1=Abramowitz|first1=Alan I.|last2=Saunders|first2=Kyle L.|date=2008|title=Is Polarization a Myth?|url=https://www.jstor.org/stable/10.1017/s0022381608080493|journal=The Journal of Politics|volume=70|issue=2|pages=542–555|doi=10.1017/s0022381608080493|jstor=10.1017/s0022381608080493|s2cid=44020272|issn=0022-3816|url-access=subscription}}</ref> ''[[Partisan sorting]]'' refers to the extent to which the electorate "sorts" or identifies with a party based on their ideological, racial, religious, gender, or other demographic characteristics.<ref>{{Cite journal|last=Mason|first=Lilliana|date=2015|title="I Disrespectfully Agree": The Differential Effects of Partisan Sorting on Social and Issue Polarization|journal=American Journal of Political Science|volume=59|issue=1|pages=128–145|doi=10.1111/ajps.12089|jstor=24363600|issn=0092-5853|doi-access=free}}</ref><ref>{{Cite journal|last1=Mason|first1=Lilliana|last2=Wronski|first2=Julie|date=2018|title=One Tribe to Bind Them All: How Our Social Group Attachments Strengthen Partisanship|journal=Political Psychology|language=en|volume=39|issue=S1|pages=257–277|doi=10.1111/pops.12485|issn=1467-9221|doi-access=free}}</ref> ''Affective polarization'' refers to the extent to which the electorate "dislikes" or "distrusts" those from other parties.<ref>{{Cite journal|last1=Iyengar|first1=Shanto|last2=Lelkes|first2=Yphtach|last3=Levendusky|first3=Matthew|last4=Malhotra|first4=Neil|last5=Westwood|first5=Sean J.|date=2019-05-11|title=The Origins and Consequences of Affective Polarization in the United States|journal=Annual Review of Political Science|language=en|volume=22|issue=1|pages=129–146|doi=10.1146/annurev-polisci-051117-073034|issn=1094-2939|doi-access=free}}</ref>

Political scientists who study mass polarization generally rely on data from [[opinion polls]] and election surveys. They look for trends in respondents' opinions on a given issue, their voting history, and their political ideology (conservative, liberal, moderate, etc.), and they try to relate those trends to respondents' party identification and other potentially polarizing factors (like geographic location or income bracket).<ref name="dimaggio-96" /><ref name="hetherington-09" /> Political scientists typically limit their inquiry to issues and questions that have been constant over time, in order to compare the present day to what the political climate has historically been.<ref name="claassen-08" /> Some of recent studies also use decision-making games to measure the extent to which ingroup members discriminate outgroup members relative to their group members.<ref name="doi.org" />

Recent academic work suggests that intolerance at the ideological extremes can lead to polarization with opinions more polarized than identities, intolerance among moderates improves cohesion.<ref>{{Cite journal |last1=Genicot |first1=Garance |year=2022 |title=Tolerance and Compromise in Social Networks |url=https://www.journals.uchicago.edu/doi/abs/10.1086/717041 |journal=Journal of Political Economy |volume=130 |pages=94–120 |doi=10.1086/717041 |s2cid=242818458 |access-date=2021-01-29|url-access=subscription }}</ref>

Some political scientists argue that polarization requires divergence on a broad range of issues,<ref name="dimaggio-96" /><ref name="fiorina-08" /> while others argue that only a few issues are required.<ref name="baldassarri-08" /><ref name="abramowitz-08" /><ref name="bafumi-09" /> [[File:ANES_Affective_Polarization_through_2020.jpg|thumb|330x330px|Affective polarization in the U.S. (1976-2020)<ref>{{Cite web |title=The Guide to Public Opinion and Electoral Behavior |url=https://electionstudies.org/data-tools/anes-guide/anes-guide.html?chart=affective_polarization_parties |access-date=2024-09-16 |website=electionstudies.org |publisher=American National Election Studies}}</ref>]]

=== Affective polarization ===
Affective polarization refers to the phenomenon where individuals' feelings and emotions towards members of their own political party or group become more positive, while their feelings towards members of the opposing party or group become more negative. This can lead to increased hostility and a lack of willingness to compromise or work together with people who hold different political views.<ref>Iyengar, S., Lelkes, Y., Levendusky, M., Malhotra, N., & Westwood, S. J. (2019). The 
Origins and Consequences of Affective Polarization in the United States. Annual Review 
of Political Science, 22(1), 129–146. https://doi.org/10.1146/annurev-polisci-051117-
073034</ref> This phenomenon can be seen in both online and offline settings, and has been on the rise in several countries in recent years.<ref>{{Cite journal |last1=Boxell |first1=Levi |last2=Gentzkow |first2=Matthew |last3=Shapiro |first3=Jesse M. |date=2022-01-25 |title=Cross-Country Trends in Affective Polarization |url=https://direct.mit.edu/rest/article/doi/10.1162/rest_a_01160/109262/Cross-Country-Trends-in-Affective-Polarization |journal=The Review of Economics and Statistics |volume=106 |issue=2 |language=en |pages=557–565 |doi=10.1162/rest_a_01160 |issn=0034-6535}}</ref><ref name="auto">{{Cite journal |last1=Hahm |first1=Hyeonho |last2=Hilpert |first2=David |last3=König |first3=Thomas |date=2023-03-30 |title=Divided We Unite: The Nature of Partyism and the Role of Coalition Partnership in Europe |journal=American Political Science Review |language=en |volume=118 |pages=69–87 |doi=10.1017/S0003055423000266 |issn=0003-0554 |s2cid=257873474 |doi-access=free}}</ref> Affective polarization has been estimated via a variety of methods, including the Affective Polarization Scale and regression methods applied to social media data.<ref>{{cite journal |last1=McMurtrie |first1=Brandon |last2=Philipp |first2=Michael |last3=Hebden |first3=Ross |last4=Williams |first4=Matt |date=2024 |title=Development and Validation of the Affective Polarization Scale |journal=[[International Review of Social Psychology]] |volume=37 |issue=1 |doi=10.5334/irsp.926|doi-access=free }}</ref><ref>{{Cite book |last1=Nettasinghe |first1=Buddhika |last2=Rao |first2=Ashwin |last3=Jiang |first3=Bohan |last4=Percus |first4=Allon G. |last5=Lerman |first5=Kristina |chapter=In-Group Love, Out-Group Hate: A Framework to Measure Affective Polarization via Contentious Online Discussions |date=2025-04-22 |title=Proceedings of the ACM on Web Conference 2025 |chapter-url=https://dl.acm.org/doi/abs/10.1145/3696410.3714935 |series=WWW '25 |location=New York, NY, USA |publisher=Association for Computing Machinery |pages=560–575 |doi=10.1145/3696410.3714935 |isbn=979-8-4007-1274-6|arxiv=2412.14414 }}</ref>

Affective polarization may lead to aggressive attitudes and behaviors toward members of other ideological groups within the same country.<ref>{{cite book |last1=Hetherington |first1=Marc J. |title=Why Washington Won't Work |last2=Rudolph |first2=Thomas J. |date=2015 |publisher=University of Chicago Press |isbn=9780226299358 |location=Chicago}}</ref> Extreme affective polarization may even lead to dangerous consequences like societal disintegration and ideological sorting.<ref>{{cite journal |last1=Orian Harel |first1=Tal |last2=Maoz |first2=Ifat |last3=Halperin |first3=Eran |title=A conflict within a conflict: Intragroup ideological polarization and intergroup intractable conflict |journal=Current Opinion in Behavioral Sciences |date=2020 |volume=34 |pages=52–57 |doi=10.1016/j.cobeha.2019.11.013 }}</ref><ref>{{Cite journal |last1=Nettasinghe |first1=Buddhika |last2=Percus |first2=Allon G |last3=Lerman |first3=Kristina |date=2025-03-01 |title=How out-group animosity can shape partisan divisions: A model of affective polarization |url=https://academic.oup.com/pnasnexus/article/4/3/pgaf082/8069205 |journal=PNAS Nexus |volume=4 |issue=3 |pages=pgaf082 |doi=10.1093/pnasnexus/pgaf082 |pmid=40125444 |pmc=11927084 |issn=2752-6542|arxiv=2403.16940 }}</ref> Affective polarization can be reduced by various means, such as feeling sadness together as a group (which often happens during Memorial Days).<ref>{{cite journal |last1=Gur |first1=Tamar |last2=Ayal |first2=Shahar |last3=Wagner |first3=Magnus |last4=Adler |first4=Eli |last5=Halperin |first5=Eran |title=A Group that Grieves Together Stays Together: Examining the Impact of Holocaust Memorial Day in Israel on Affective Polarization |journal=Political Psychology |doi=10.1111/pops.1295|doi-broken-date=1 November 2024 }}</ref> A high prevalence of respectful discussions with political others may also reduce affective polarization by increasing political tolerance and inter-party trust.<ref>{{cite journal |last1=Kubin |first1=Emily |last2=Puryear |first2=Curtis |last3=Schein |first3=Chelsea |last4=Gray |first4=Kurt |title=Personal experiences bridge moral and political divides better than facts |journal=Proceedings of the National Academy of Sciences |date=2021 |volume=118 |issue=6 |doi=10.1073/pnas.2008389118|doi-access=free |pmid=33495361 |pmc=8017692 |bibcode=2021PNAS..11808389K }}</ref> High salience of a national common identity may also reduce affective polarization, as members of other parties are suddenly seen as in-group members.