Psychological phenomena in deliberation have long been a focus of inquiry in deliberative democracy, as documented in several excellent overviews (e.g. Gastil 2018; Karpowitz & Mendelberg 2018; Lupia et al. 2012; Mendelberg 2002; Myers & Mendelberg 2013; Pincock 2012). This section summarizes selected major findings from the initial phases of inquiry into psychological aspects of deliberation, with an emphasis on topics directly related to articles in this special issue.

One of the hallmarks of a deliberative democracy is a well-informed public. Deliberative participation improves issue-specific knowledge (Barabas 2004; Fishkin 2009; Min 2007) and understanding of others’ issue-related arguments (Cappella et al. 2002). The public can become more knowledgeable and less misinformed vicariously when policy analyses of deliberating citizens are publicly distributed (Gastil & Knobloch 2020; Reedy et al. 2021). Deliberative participation improves understanding beyond mere knowledge by conferring greater coherence (Gastil & Dillard 1999) or single-peakedness (Farrar et al. 2010; List et al. 2013) of policy attitudes, and facilitated group deliberation fosters attitude changes (Blais et al. 2008; Farrar et al. 2010).

Scholars have explored how issue framing influences citizens’ beliefs and attitudes (Chong & Druckman 2007). Participants who have been exposed to different framings are more likely to express cross-cutting views, and deliberative discussion can neutralize frames’ effects on participants’ issue-attitudes, but it does not if all participants are exposed to the same frame (Druckman 2004; Druckman & Nelson 2003).

A group-level psychological phenomenon of note for deliberative research is group polarization, small-groups’ tendency to intensify their initial issue-attitudes if engaging in unstructured discussion (Sunstein 2002). Studies show the use of facilitation, clear procedural rules reflecting deliberative norms, and balanced informational materials tends to prevent group polarization (e.g. Fishkin et al. 2010; Luskin et al. 2002; Grönlund et al. 2017; Strandberg et al. 2019); deliberations lacking these features tend to exhibit group polarization (e.g. Schkade et al. 2007).

The most developed early research concerning emotions and deliberation drew from Affective Intelligence Theory (Marcus, Neuman & MacKuen 2000). Utilizing studies of citizen deliberation in the public sphere, Marcus, MacKuen, Wolak, and Keele argue that anxiety likely increases deliberation among citizens; enthusiasm may increase participation but likely not deliberation; and loathing, anger, and aversion lead citizens to resist new information and deliberation (MacKuen et al. 2010; Marcus 2002; Wolak & Marcus 2007). Subsequent experiments provided preliminary confirming evidence regarding anxiety (McClain 2009), while questioning whether enthusiasm (McClain 2009) and anger (Kim 2016) might also lead to deliberation. Beyond Affective Intelligence, researchers have examined positive and negative emotions in online forums (Sobkowicz & Sobkowicz 2012), emotions in juries (Hickerson & Gastil 2008), and emotionally-laden discourse (Martin 2012) and biographical affect (Komporozos-Athanasiou & Thompson 2015) in a deliberative patient forum.

Recently, scholars of deliberation have concentrated their research on a wider array of psychological phenomena, including lay conceptualizations of deliberation, emotions, perspective-taking, relational schemata, communication goals, group identity, and social learning. Several works explore lay people’s conceptions of deliberative processes and elements of deliberation, such as listening and sources of policy information.

The idea that deliberation involves a unique type of listening has sparked interesting conversations about how people process information in small group deliberation. For example, Parks (2019: 25) investigated the values that lay people associated with effective listening in dialogue, including openness and ‘critical thinking’. Related work on listening in deliberation includes Scudder’s (2020) and Bourgault’s (2020) conceptualizations of listening within normative deliberative theory, Mansbridge and Latura’s (2016) call to emphasize listening in deliberative theorizing and research to counter political polarization, and the study of Hendriks et al. (2019) identifying different types of citizens’ listening practices during informal deliberation and those practices’ functions in deliberative systems.

Current studies have examined citizens’ perspectives on the types of information that should be included in deliberation. For example, Lind (2020) identified three different lay epistemologies of public decision making, each with its kinds of required knowledge and recipients of that knowledge. Huntington (2019) examined citizens’ perceptions of Internet memes as a source of information in public political dialogue. That analysis of survey data revealed the so-called third-person effect: respondents reported believing that memes influenced the thinking and beliefs of other citizens, rather than themselves. Studies like Lind’s and Huntington’s explore ways that citizens’ mental models of public deliberation and its components can shape their expectations of deliberative processes.

Recent years have seen an uptick in studies on emotions and deliberation. Neblo (2020) identified twelve roles for emotions in deliberation: normative relevance, motivation to deliberate, inputs, outputs, unmediated inputs, background, enabling conditions, cross check, analogs, application, motivation to act, and struggles for recognition. Saam (2018), using citizen interviews from several deliberative forums, found that disappointment and shame promote exit rather than deliberation and reinforce inequalities because higher status individuals have higher emotional capital, while hope strengthens everyone’s voice and participation irrespective of emotional capital. Analyzing the transcript of a Citizens’ Initiative Review (CIR), Johnson, Black, and Knobloch (2017) found that the competitive-collaborative structure of the CIR was conducive to emotional expression that contributed to deliberation but still allowed participants, with the assistance of moderators, to remain focused on factual accuracy and producing their written statement. Johnson, Morrell and Black (2019) analyzed participant surveys and observer notes from three further CIRs and concluded that during the four-day deliberation enthusiasm was common throughout, happiness steadily increased, anxiety peaked early, sympathy was moderately present, anger was moderately present and peaked on day three, and sadness was uncommon; they theorize that deliberative procedures were likely key in explaining these results. Suiter et al. (2020) utilized a survey experiment and discovered that even non-participants who read balanced information generated by a CIR had greater affective empathy for the other side of the policy debate.

Related studies have delved into the psychological implications of perspective-taking. Muradova (2020: 645) set out ‘a theory of perspective-taking in deliberation’, holding that the degree to which participants engage in reflection is tied to the degree to which participants view issues and policy options from the point of view of other participants (see also Muradova 2021). Features of formal deliberative processes likely to encourage perspective-taking were ‘the presence of diverse perspectives’ and the sharing of ‘personal stories’ (Muradova 2020: 649). Grönlund, Herne, and Setälä (2017: 457) drew on data from a deliberative mini-public experiment to argue that participation in deliberation could increase ‘outgroup empathy’, which they measured as cognitive perspective-taking. Ugarriza and Nussio (2017: 7) found experimental evidence that discussion procedures designed to promote perspective-taking—by encouraging participants to share personal stories, or engage in ‘perspective-giving’—affected participants’ attitudes towards one another.

Other research has examined the role of cognitive structures concerning interpersonal relationships in deliberation. Brinker (2019) drew on relational framing theory (Dillard et al. 1996) to investigate whether cognitive structures that individuals use to interpret the relational dimension of interpersonal communication influenced participants’ reasoning during deliberation. Results showed that participants’ interpretations of the group’s relational dynamics influenced participants’ judgments about the quality of arguments, their endorsements of those arguments, and the degree to which motivated reasoning affected those judgments.

Recent research has also shed light on how goals shape informal deliberative behavior. Eveland et al. (2011) and Morey and Yamamoto (2020) examined the communication goals that individuals prioritized when engaging in informal political deliberations.

Group identity—often characterized as social identity (Tajfel & Turner 2004)—is another focus of psychological inquiry in deliberation, partly due to evidence that group identity intensifies political polarization (e.g. Mason 2018). Some scholars have investigated group identity as an outcome of deliberative participation (e.g. Felicetti et al. 2012, Knobloch & Gastil 2015). More recent research has explored how group identity influences deliberative outcomes. Strickler (2018), for example, found that group-identity-based political partisanship was significantly associated with reduced deliberative reciprocity—the willingness to judge arguments as reasonable and worth considering—toward political opponents, and increased reciprocity toward co-partisans. Batalha et al. (2019) demonstrated that deliberative participants identified more strongly with the superordinate group of their mini-public—the Australian Citizens’ Parliament—than with the subordinate group of their own electoral district, and concluded that deliberative participants can possess multiple group identities that can each shape attitudinal outcomes of deliberation.

Another social-psychological topic of recent inquiry in deliberation is social learning (Bandura 1986; Patterson 1975–1993; Rotter 1982), which deliberation scholars employ in two senses. The first derives from Bandura’s (1986) theory of social learning as a psychosocial process by which individuals change their thoughts and behavior by observing others’ behavior, and which can promote gains in participants’ clarity of speech, use of non-dominant behavior, awareness of opponents’ reasons, and ‘recognition of opposing values’ (Gastil 2004: 325). A second, broader definition of social learning—as changes in beliefs occurring during group interactions, or collective learning—has been more commonly employed in deliberation research (e.g. Barraclough 2013; Dryzek 2013; Rodela, 2013). For some scholars, social learning more specifically involves acquiring knowledge of the views (Kanra 2009; Nikkels et al. 2021) or values (Kenter et al. 2016; Schusler 2003) of other deliberative participants. Some scholars view social learning as involving particular psychological processes, such as perspective-taking (Kanra 2009; Renson 2020) or processes mediated by individuals’ beliefs (Kenter et al. 2016), such as planned behavior (Ajzen 1991). Scholars argue that social learning can occur across deep social divides (Barraclough 2013; Dryzek 2005), as Kanra (2009) showed among diverse participants in a women’s peace organization in Turkey. Social learning promotes outcomes ranging from ‘common purpose[s]’ (Schusler et al. 2003: 312) to improved attitudes towards outgroup members (Kanra 2009) and greater esteem for the public good (Kenter et al. 2016).

The latest deliberative social-learning scholarship foregrounds two themes. The first is social learning in diverse settings, as in Menon and Hartz-Karp’s (2019) study of social learning in deliberative processes in India and De Vente et al.’s (2016) investigation of social learning during deliberations in 13 nations. The second is more complex models of social learning. For example, Renson (2020) demonstrated social learning concerning beliefs and attitudes among participatory-budgeting participants, while Kenter et al.’s (2016) social-learning model integrates multiple psycho-social processes to explain how participants’ beliefs mediate associations between broad value commitments and value-criteria in deliberation.

The articles in this special issue offer fresh theoretical and empirical insights on several recent topics concerning psychological aspects of deliberation, while extending knowledge on long-standing topics in the field.

Analyzing qualitative data from a CIR about medical-marijuana legalization, Fisher et al. uncover new categories of reasoning employed by deliberating citizens. Moreover, Fisher et al. explore associations between those categories—which include states of uncertainty and processes of questioning—and types of expression of disagreement. Khoban employed survey experiments to investigate citizens’ mental models of deliberative interactions during hypothetical mini-publics. Contributing to recent research on citizens’ lay conceptualizations of deliberation as well as social-identity dynamics in deliberative processes, while incorporating concepts from prior research on framing in deliberation, Khoban explores whether cues about the social groups to be included in a prospective mini-public influenced citizens’ expectations concerning deliberation.

Also building on recent research concerning social identity in deliberation, Wright theorizes about the threat that social identity poses to persuasion-based accounts of democratic deliberation. Wright draws on principles from Mary Parker Follett’s deliberative theory to set out a new framework for citizen deliberation based on the creative development of mutually beneficial solutions.

Two articles provide fresh insights on emotions in deliberation. Replicating an earlier study (Johnson et al. 2019), Morrell et al. discover evidence from three CIRs confirming their findings that deliberative procedures influence participants’ emotions at different stages of the deliberative process in a mini-public. Providing a practitioner perspective on emotions in deliberation, Stains and Sarrouf explain how the experience of powerful emotions—especially those arising from polarizing social identities—can inhibit deliberation. For these authors, structured dialogue procedures can enable citizens to control such emotions and enhance their sense of agency in preparation for constructive participation in deliberative decision making.

Extending recent scholarship on goals in informal deliberation, Richards and Neblo’s theoretical model explains how formal and informal deliberative contexts influence citizens’ communicative goals, which in turn shape citizens’ reason-giving behavior. Communicative plans—activated during processes of information seeking and sense-making—are expected to mediate associations between goals and communicative practices.

Apprehending how people understand and relate to one another is critical to the political psychology of deliberation. Considered together, the articles in this special issue highlight innovative theorizing and empirical research in this area and illuminate paths of further inquiry in this vital domain.