We explore the dynamics of affective partisanship and policy divergence in a behavioral voting model. Voters are adaptive and influenced by partisan affect, while political parties are rational and office motivated. We show that the affective partisanship of the electorate and the divergence of party platforms can be mutually reinforcing, thus providing an explanation for the observed co-movement of affective and elite polarization in recent decades. Whether the induced behavioral path exhibits low polarization or high polarization depends on the salience of group identity and the number of moderate voters. Thus, shocks to those factors, perhaps due to such events as economic crises or war, can lead to the polarization or depolarization of the electorate and of the elite.

Public health officials have faced resistance in their efforts to promote mask-wearing to counter the spread of COVID-19. One approach to promoting behavior change is to alert people to the fact that a behavior is common (a descriptive norm). However, partisan differences in pandemic mitigation behavior mean that Americans may be especially (in)sensitive to information about behavioral norms depending on the party affiliation of the group in question. In July–August 2020, we tested the effects of providing information to respondents about how many Americans, co-partisans, or out-partisans report wearing masks regularly on both mask-wearing intentions and on the perceived effectiveness of masks. Learning that a majority of Americans report wearing masks regularly increases mask-wearing intentions and perceived effectiveness, though the effects of this information are not distinguishable from other treatments.

This study investigates to what extent affective polarization, and more specifically hostility towards opposing party supporters, finds its roots in ideological differences. We look into the way out-groups are constructed when there are more than two political parties, and at the role of ideology in this process. Hereby we position ourselves in the discussion between those who argue that affective polarization finds its root more strongly in group attachments vs. those who argue that it is mostly rooted in ideological differences. We conduct our study in the context of the highly fragmented multi-party system of Belgium which enables us to analytically disentangle party label cues from ideological distance. Our findings demonstrate that affective polarization is largely rooted in ideological differences between party electorates in Belgium. Additionally, we find that this particularly holds for citizens who are more ideologically invested, namely those with higher political interest and more extreme ideological views.

Do populist radical right (PRR) parties fuel affective polarization? If so, how and under which circumstances? Based on a comparative cross-country analysis covering 103 elections in 28 European countries and an examination of longitudinal data from the Netherlands, we show that PRR parties occupy a particular position in the affective political landscape because they both radiate and receive high levels of dislike. In other words, supporters of PRR parties are uniquely (and homogeneously) negative about (supporters of) mainstream parties and vice versa. Our analyses suggest that these high levels of antipathy are most likely due to the combination of these parties' nativism and populism – two different forms of ingroup–outgroup thinking. Our findings also suggest that greater electoral success by PRR parties reduces dislike towards them, while government participation appears threatening to all voters except coalition partners.

Our research speaks to the ongoing debate over the extent and severity of partisan political divisions in American society. We employ behavioral experiments to probe for affective polarization using dictator, trust, and public goods games with party identification treatments. We find that subjects who identify politically with the Democratic or Republican Party and ideologically as liberals and conservatives display stronger affective biases than politically unaffiliated and ideological moderates. Partisan subjects are less altruistic, less trusting, and less likely to contribute to a mutually beneficial public good when paired with members of the opposing party. Compared to other behavioral studies, our research suggests increasing levels of affective polarization in the way Americans relate to one another politically, bordering on the entrenched divisions one commonly sees in conflict or post-conflict societies. To overcome affective polarization, our research points to inter-group contact as a mechanism for increasing trust and bridging political divides.

Affective polarization – partisans’ dislike and distrust of those from the other party – has reached historically high levels in the United States. While numerous studies estimate its effect on apolitical outcomes (e.g., dating and economic transactions), we know much less about its effects on political beliefs. We argue that those who exhibit high levels of affective polarization politicize ostensibly apolitical issues and actors. An experiment focused on responses to COVID-19 that relies on pre-pandemic, exogenous measures of affective polarization supports our expectations. Partisans who harbor high levels of animus towards the other party do not differentiate the “United States’” response to COVID-19 from that of the Trump administration. Less affectively polarized partisans, in contrast, do not politicize evaluations of the country’s response. Our results provide evidence of how affective polarization, apart from partisanship itself, shapes substantive beliefs. Affective polarization has political consequences and political beliefs stem, in part, from partisan animus.

How much does politics affect relationship building? Previous experimental studies have come to vastly different conclusions – ranging from null to truly transformative effects. To explore these differences, this study replicates and extends previous research by conducting five survey experiments meant to expand our understanding of how politics does/does not shape the formation of romantic relationships. We find that people, indeed, are influenced by the politics of prospective partners; respondents evaluate those in the political out-group as being less attractive, less dateable, and less worthy of matchmaking efforts. However, these effects are modest in size – falling almost exactly in between previous study estimates. Our results shine light on a literature that has, up until this point, produced a chasm in study results – a vital task given concerns over growing levels of partisan animus in the USA and the rapidly expanding body of research on affective polarization.

I conduct an experiment which examines the impact of moral suasion on partisans engaged in uncivil arguments. Partisans often respond in vitriolic ways to politicians they disagree with, and this can engender hateful responses from partisans from the other side. This phenomenon was especially common during the contentious 2016 US Presidential Election. Using Twitter accounts that I controlled, I sanctioned people engaged partisan incivility in October 2016. I found that messages containing moral suasion were more effective at reducing incivility than were messages with no moral content in the first week post-treatment. There were no significant treatment effects in the first day post-treatment, emphasizing the need for research designs that measure effect duration. The type of moral suasion employed, however, did not have the expected differential effect on either Republicans or Democrats. These effects were significantly moderated by the anonymity of the subjects.

A well-functioning democracy requires a degree of mutual respect and a willingness to talk across political divides. Yet numerous studies have shown that many electorates are polarized along partisan lines, with animosity towards the partisan out-group. This article further develops the idea of affective polarization, not by partisanship, but instead by identification with opinion-based groups. Examining social identities formed during Britain's 2016 referendum on European Union membership, the study uses surveys and experiments to measure the intensity of partisan and Brexit-related affective polarization. The results show that Brexit identities are prevalent, felt to be personally important and cut across traditional party lines. These identities generate affective polarization as intense as that of partisanship in terms of stereotyping, prejudice and various evaluative biases, convincingly demonstrating that affective polarization can emerge from identities beyond partisanship.

A wealth of research documents the rise of affective polarization, or the increasing disdain for the out-party in American politics. In this paper, we analyze ANES data from 1988 to 2016 to investigate the contribution of core value polarization to the phenomenon of out-party enmity. We find that greater differences in fundamental principles relate significantly to emotionally intense evaluations of the opposing party and its candidates, as well as the ideological out-group, independent of issue attitude extremity and the strength of one's partisan and ideological identities. Moreover, ANES panel data from 1992 to 1996 reveal that past value extremity promotes future affective polarization. These results are important for our understanding of the nature and extent of value-based polarization in American politics.

Elite partisan polarization has been found to have several potentially problematic effects on citizens, such as creating political distrust and different types of polarization among partisans. However, it remains unclear whether these effects are caused by the parties moving apart in terms of issue positions (issue polarization) or by the rise of disrespectful rhetoric (incivility). In the literature, these two dimensions of elite polarization often appear to affect citizens in similar ways, but typical research designs have not been well suited to disentangling their effects. To determine their unique effects, four studies have been conducted using original designs and a mix of experimental and observational data. The results show that issue polarization and incivility have clearly distinct effects. A more uncivil tone lowers political trust, but increasing issue polarization does not. Conversely, only issue polarization creates attitude polarization among partisans. Both aspects of elite polarization create affective polarization.

Recent work on political divisions in the mass public has identified several manifestations of polarization linked to different types of attitudes, orientations, and behaviors. Of these, affective polarization and perceived polarization have attracted increasing attention, though we still know fairly little of the links between these variants of polarization. In this paper, we examine the association between affective and perceived polarization, with an aim toward disentangling any potential causal relationship between the two processes. Using two sets of nationally representative panel data from 1992 to 1996 and 2008 to 2009, we find evidence that affective polarization causes perceived polarization, and that perceived polarization is not related to future affective polarization. Stratifying the models by level of political information, we find that the strength and statistical significance of the relationships between past and future values of affective and perceived polarization are conditional on political sophistication: more sophisticated individuals exhibit stronger relationships.