The term polarisation was named word of the year in 2023 by the FundéuRAE, following a period marked by an intense electoral competition and coalition agreements between parties which deepened pre-existing hostilities in Spain. Currently, the word polarisation is not only used to describe the state of the political and media arena, but a climate of confrontation caused by group bias that has been making an impression in more and more social spheres. Therefore, we see dynamics of animosity among the political elite as well as among supporters of different parties and ideological blocs. Political identities transformed into social identities begin to generate processes of interpersonal discrimination and condition daily life, at the same time as the differential affect gap between us and them has widened. This type of polarisation has been named affective polarisation by the academic world (Iyengar et al., 2019), a type of polarisation expressed at an individual level as an intense dislike of the supporters of other parties (known as the out-group) and at the same time as a strong sense of belonging or friendliness toward the voters of one’s own party or ideological bloc (referred to as the in-group). In recent years, this affective polarisation has led both to expressions of rejection and exclusion, and a denial of the legitimacy of those governments that are not to one’s liking. This questioning of the legitimacy of the rival foreshadows episodes of political violence, as was seen on January 6, 2021 in the assault on the Capitol in Washington, D.C. or in the riots on January 8, 2023 involving Bolsonaro’s supporters in the Planalto Palace in Brasilia.

In the case of Spain, different studies have shown that our country is one of the most polarised democracies in the world (Gidron et al., 2020; Edelman Trust Barometer, 2023). Furthermore, in our country, there is evidence of a higher correlation between the animosity toward rival parties and the animosity toward their voters; that is, Spaniards are turning their partisan sentiments into expressions of social distancing (Tichelbaecker et al., 2023). Over the past few years, this climate of polarisation has been increasing to limits never before seen, as stated in the IV National Polarisation Survey carried out by the Murcian Public Opinion Research Center (CEMOP, 2024), where 82% of the respondents state that the level of tension is greater than four years ago. The high degree of social and affective polarisation in Spain have been explained, among other reasons, by the territorial conflict in Catalonia and the appearance of populist parties such as Vox, that generate a strong sense of threat (Balcells et al., 2024; Rojo et al., 2023). However, neither of these factors by itself, nor even when combined, can explain the exponential growth of affective polarisation experienced in the past four years, with percentage variations above 30%, according to data in the aforementioned CEMOP’s IV National Polarisation Survey. The climate of tension that has become the norm in our political life no longer tells us only about the existence of an ideological or issue-based polarisation, the result of logical competition between parties of different stripes, but also that the discrepancies have reached a new dimension, conditioning social relations, the possibility of coming to political agreements and the fundamental consensus on the rules of the democratic game. Political polarisation, transformed into social and emotional polarisation, has created a context of isolated and hostile tribes; social and political communities that are fractured and incapable of cooperating to make progress in addressing the collective challenges.

Almost everything about affective polarisation has been studied: its origins, proposing approaches linked to social identity theory (SIT) and ideological polarisation (Lelkes, 2021); factors that can explain its rapid growth, in particular from institutional factors, such as the electoral system or the party system models, which are developed in frameworks of centrifugal competition where extremist and/or radical parties are present, to structural factors caused by the 2007-2008 financial crisis, such as the unemployment rate or the levels of social inequalities (Gidron et al., 2020). In addition to these factors, attention has been focused on another type of variables of a communication nature, relating to the effect of the media and social networks, which appear to play a crucial role in the exacerbation of the phenomenon. Also analysed were the consequences of affective polarisation for governability, for the continued commitment of citizens to the norms and routines of the democratic system (whether they benefit the in-group or not) and even for health and emotional welfare (Nelson, 2022).

There are still some avenues of research to explore in the future: firstly, understanding polarisation as a strategy that helps parties communicate with their target audience, and divides and anchors society in identities that it is difficult to move between; secondly, the question arises as to how to intervene in society to begin the depolarisation process both at elite levels as well as those of the media and citizens. We venture to say that the defining word in the future will be precisely that: depolarisation. And that the scientific community will begin working assiduously on tools that will reduce levels of conflict so as to facilitate cooperation between those who think differently. Indeed, already in the twentieth century, social psychologists such as Gordon Allport (1954) and Muzafar Sherif et al. (1961) began testing methods for reducing intergroup animosity and prejudices. It is a question of checking how far this evidence can be transferred to the political field, with its particular conditioning factors.

Regarding the first of these issues, preliminary evidence appears to suggest that negative campaigns can cause greater affective polarisation, but to date, only a few small studies have tested this effect (Iyengar et al., 2012; Martin and Nai, 2024). Polarisation could have consciously become a discursive strategy of the political elite, immersed in a permanent campaign that feeds directly on this type of adversarial rhetoric. Negative communication strengthens the identity of those who feel close to the party or the lead source of this type of communication, and, in turn, it introduces elements that foster a profound distancing from the rival party or leader, hindering the demobilisation and conversion processes. Negative communication ensures that the gap between the main parties in the contest widens and that the cost of “changing sides” is excessive for voters. That option becomes morally reprehensible. To this end, negative communication classifies all individuals in each identity group through stereotypes that exaggerate the actual degree of disagreement and undermine certain qualities in rivals. At the same time, according to Nai and Maier (2023), exposure to attack campaigns causes an emotional reaction among those who feel close to the target.

Although one of the main functions of political parties is to bring together individuals with similar interests, the parties have currently become the cause of division, beyond what could be expected in a traditional competitive setting. Partisan rhetoric and, more specifically, the use of an intense tone against political opponents cause an aggressive polarisation spiral (Lau et al., 2017), while identification processes with a highly negative basis (negative partisanship) are emerging. If one of the aims of this negative communication is to produce dichotomous analytical frameworks that establish a “supra-identity” which facilitates the communication process in a heterogeneous and fragmented world, the second aim is that this “supra-identity” be clearly antagonistic to the other categories, through discursive logic that associates rival identities with morally objectionable values.

This new line of research on affective polarisation as a communication strategy should not deal with its origins, causes or consequences, but rather its emergence as a political resource that enables more effective communication with the recipient of the message, anchoring their predispositions and turning them into active votes. The question here is not so much to establish the connection between polarisation and negative communication, as to accept that that connection exists, that the parties know of it and that, therefore, the connection is used to aid persuasive communication.

The second line to explore relates to the mechanisms and tools of depolarisation. For the moment, the experiments carried out on depolarisation have been focused on the correction of misperceptions and on the hypothesis of intergroup contact (Voelkel et al., 2022). Evidence has also emerged relating to the positive effects of a more diverse media diet when it comes to moderating partisan extremism. Indeed, in his essay on the state of the art included in this special issue, Professor Shanto Iyengar underlines the need to continue gathering evidence of the causal mechanisms that alter affective polarisation levels, while it is also necessary to reflect on the applicability in the real world of the vast majority of depolarisation experiments carried out. Let us think, for example, about the works lead by Santoro and Broockman (2022) on promoting talks between Democrats and Republicans to mitigate party animosity. Even accepting the causal effect of these talks on attitudes - always contingent on a series of conditions upon the type of issue, the status relationship or the tone used - it would be difficult for this type of interaction to take place on a large scale in the real world. Scientific research cannot settle for counterfactual exercises with zero social impact because they are unfeasible, but rather must aspire to offer practical solutions - deployable from the institutional area - that foster cohesion, commitment to democracy, and coexistence.

The varying studies included in this special issue, which readers have before them, discuss underexplored topics relating to the social and democratic challenge of affective polarisation. Three of them present unpublished results from the POLARIZA project (ref. 21876/PI/22), funded by the Agency for Science and Technology in the Region of Murcia - Séneca Foundation, to whom we would like to give our thanks for their support.

The article Misperceptions and affective polarisation: evidence from Spain, written by Ismael Crespo, Alberto Mora and José Miguel Rojo, researchers at the University of Murcia, establishes that misperceptions are a strong predictor of negative feelings toward a party. In that regard, the indicator of misperceptions becomes a variable with a high degree of influence when it comes to explaining the score awarded on the feeling thermometer. The article analyses in detail the perceptual deviations which generate a feeling of false polarisation, as well as demonstrating that identities skew perceptual judgements. Furthermore, it verifies a broad level of perceptual deviations in Spain concerning what Vox voters believe. This article not only represents a groundbreaking approach in the topic of misperceptions in Spain and their effects, it also has significant implications for the study of radical right voters, their preferences and self-perceptions, which are repeatedly stigmatised.

As Crespo, Mora and Rojo acknowledge, misperceptions about rivals are spread and magnified by party strategies to facilitate differentiation, but the media and social networks also tend to over-represent the most extreme profile of each group, contributing to the creation of partisan stereotypes that lead us to overestimate the degree of polarisation in a country. Not only have the effects of the media in relation to perceptions been highlighted, but how the media diet can intensify group bias has also been considered. For this reason, the article Beyond ideology: influence of the media diet on affective polarisation in Spain by researchers Inmaculada Melero, María Quiles and María Isabel López Palazón draws important conclusions about the influence of selective exposure and the diversity of the media diet - especially television - on individual levels of affective polarisation. Beforehand, they present an interesting analysis of the ideological segregation of the audiences of the main television channels and newspapers in Spain, calculating indicators of ideological polarisation of those two media subsystems. Thanks to this study, we understand the effects of maximising partisan bias that continued use of pro-attitudinal media represents.

Following the analysis of the effects of the media diet, the article by Nieves Lagares, María Pereira and Erika Jaráiz identifies the existence of an emotional regime common among Vox voters. To that end, they use three key moments in the history of this party: the Andalusian elections in 2018, the Catalan elections in 2021, and the Castile and Leon elections in 2022. The innovation contributed by this article lies in the analysis of discrete emotions of differing valence that are organised around three dimensions: enthusiasm, anxiety and aversion. Affective polarisation studies often use broad feeling thermometers that fail to grasp the complex range of emotions included within the two poles of valence. Paying attention to discrete emotions and their specific contribution to the processes of polarisation and development of the partisan identification is a line of research that is still underexplored (Bakker and Lelkes, 2024), which obliges us to make precise conceptual distinctions between the occasionally intermingled concepts of emotions, affects, feelings and identities. Therefore, distinguishing between enthusiasm, hope, fear, rage, hate and contempt provides a far richer and deeper analysis than simply pitting warm feelings against cold feelings. Thus, the authors succeed in connecting the advances in political psychology, and more specifically in Affective Intelligence Theory, with the affective polarisation studies that have tended to highlight the unique position of extreme right-wing parties and their voters within this dynamic.

This issue includes two further analyses. Irene Palacios, Antonia Martínez and Antonio Garrido consider whether populist attitudes, affective polarisation and cultural backlash values are related and if these three issues condition support for democracy. Initially using an exploratory factor analysis, they confirm that the selected items permit the three underlying concepts of interest to be grasped effectively, which is an important contribution for the operationalisation and measurement of these topics. Subsequently, they demonstrate that cultural backlash has a strong negative influence on abstract support for democracy, while this noticeable effect is not seen in the case of affective polarisation or populist attitudes. Democratic legitimacy is only questioned when populist attitudes, cultural backlash values and affective polarisation in the youngest individuals are all combined. This encourages us to think that the manner in which affective polarisation damages democracy is not through a generic questioning of democratic values, but rather by creating more “hypocritical” positions which make compliance of the rules contingent on the benefit of the in-group (Simonovits et al., 2022).

Moreover, Natalia Aruguete and Ernesto Calvo, building on the role attributed to social networks as polarising ecosystems, wonder about the limits that fact-checking corrections could have in polarised contexts. Using experimental methodology and taking Argentina as a case study, the authors highlight different conditioning elements of the tendency to share fact checks and the interaction that the presence of polarising digital messages plays in this predisposition. The results are encouraging in regard to the potential that efforts to combat disinformation could have even in strongly divided social settings. Limiting circulation of false content on social networks may constitute a strategic tool for depolarisation, since this content is intended to heighten negative feelings toward rivals and increase misperceptions.

Lastly, we would like to thank Professor Shanto Iyengar for his participation in this special issue with an analysis of the state of the art, in which the following are discussed: the current characteristics of polarisation in the United States (in an election year of great importance), the different methodologies for measure the phenomenon and the social conditions that foster polarisation. The landmark studies by Professor Iyengar began an intense academic debate about affective polarisation over a decade ago; a debate which today, following a notable consensus on the causes and consequences, is beginning to be used in the tools of depolarisation. This matter urges us to continue exploring the impact of disinformation, misperceptions and political communication strategies with the aim of finding, within academia, solutions which can be made available to society. Similarly, we appreciate the hard work of the entire editorial team and the reviewers for having contributed with their comments to enhancing the quality of all the papers.