Sources and References

Primary sources — All readings are research papers assigned by the course. Full citations below.

Assigned papers:

• Slovic, P. (2007). “If I look at the mass I will never act”: Psychic numbing and genocide. Judgment and Decision Making, 2(2), 79–95.
• Inbar, Y., & Lammers, J. (2012). Political diversity in social and personality psychology. Perspectives on Psychological Science, 7(5), 496–503.
• Jost, J. T. (2009). Elective affinities in political ideology: Why people end up being conservative or liberal. Psychological Science, 18(3), 129–135.
• Haidt, J., Graham, J., & Joseph, C. (2009). Above and below left-right: Idealism and pragmatism in the political personality. Psychological Inquiry, 20(2–3), 110–119.
• Buttrick, N., Moulder, R., & Oishi, S. (2020). Historical change in the moral foundations of political persuasion. Personality and Social Psychology Bulletin, 46(11), 1523–1537.
• Bilewicz, M. (2022). Historical trauma and intergroup relations. Advances in Political Psychology, 43(S1), 149–168.
• Zmigrod, L. (2022). The psychology of ideological thinking: Insights from behavioral and brain sciences. Psychological Inquiry, 33(4), 213–232.
• Kozyreva, A., Lewandowsky, S., & Hertwig, R. (2024). Citizens versus the internet: Confronting digital challenges with cognitive tools. Psychological Science in the Public Interest, 25(1), 1–73.
• Pennycook, G., & Rand, D. G. (2021). The psychology of fake news. Trends in Cognitive Sciences, 25(5), 388–402.
• Voelkel, J. G., Chu, J., Stagnaro, M. N., Mernyk, J. S., Redekopp, C., Pink, S. L., … Willer, R. (2024). Megastudy identifying effective interventions to strengthen Americans’ democratic commitments. Science, 382(6679), eadh3289.
• Hartman, T. K., et al. (2022). Interventions to reduce partisan animosity: A review. [Review article; see also broader affective polarization intervention literature.]
• Golec de Zavala, A., & Lantos, D. (2020). Collective narcissism and its social consequences: The bad and the ugly. Current Directions in Psychological Science, 29(3), 273–278.
• Bruneau, E. G., & Kteily, N. (2017). The enemy as animal: Symmetric dehumanization during asymmetric warfare. PLOS ONE, 12(7), e0181422.
• Shnabel, N., & Nadler, A. (2015). The role of agency and morality in reconciliation processes: The perspective of the needs-based model. Current Directions in Psychological Science, 24(6), 477–483.
• Ginges, J. (2019). Sacred values and the psychology of political violence. Current Opinion in Psychology, 35, 81–85.

Supplementary texts and general resources consulted:

• Jost, J. T., & Sidanius, J. (Eds.). (2004). Political Psychology: Key Readings. Psychology Press.
• Sears, D. O., Huddy, L., & Jervis, R. (Eds.). (2003). Oxford Handbook of Political Psychology. Oxford University Press.
• Haidt, J. (2012). The Righteous Mind: Why Good People Are Divided by Politics and Religion. Pantheon.
• Tajfel, H., & Turner, J. C. (1979). An integrative theory of intergroup conflict. In W. G. Austin & S. Worchel (Eds.), The Social Psychology of Intergroup Relations (pp. 33–47). Brooks/Cole.
• Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux.
• van der Linden, S. (2023). Foolproof: Why Misinformation Infects Our Minds and How to Build Immunity. W. W. Norton.

Chapter 1: Introduction to Political Psychology

What Is Political Psychology?

Political psychology is the scientific study of the psychological processes underlying political behavior, attitudes, and institutions. It sits at the intersection of political science and psychology, drawing on cognitive psychology, social psychology, developmental psychology, and neuroscience to explain phenomena that neither discipline can fully account for alone. Why do citizens hold the political views they do? How do leaders acquire and maintain influence? What psychological forces drive conflict, prejudice, dehumanization, and occasionally reconciliation? These are the questions of political psychology.

A Brief History of the Field

The roots of political psychology trace to early twentieth-century work on propaganda, crowd psychology (Le Bon, 1895), and psychoanalytic interpretations of political leadership. Harold Lasswell’s Psychopathology and Politics (1930) introduced systematic psychological analysis of political actors, arguing that power-seeking behavior reflected compensatory personal needs displaced onto public objects. The rise of fascism in Europe prompted a different research program: Theodor Adorno and colleagues (1950) developed the Authoritarian Personality construct, attempting to identify the personality type susceptible to fascist appeal — a line of inquiry that remains influential today through research on right-wing authoritarianism (Altemeyer) and social dominance orientation (Sidanius & Pratto).

The behavioral revolution in political science (1950s–1970s) brought survey methods and empirical rigor to the field. The American Voter (Campbell et al., 1960) documented the role of party identification and partisan attitudes in voting behavior. The emergence of cognitive psychology in the 1970s shifted attention toward information processing, schema theory, and heuristics in political judgment. By the 1980s and 1990s, social identity theory (Tajfel & Turner) had become central to understanding group-based political behavior — why people vote with their group, denigrate out-groups, and define political identity in terms of social belonging.

Contemporary political psychology is highly diverse in method (surveys, experiments, neuroimaging, computational text analysis, field experiments) and topic (ideology, prejudice, dehumanization, political violence, misinformation, democratic backsliding). The readings in this course represent the most active research fronts in the field as of the early 2020s.

Core Methods in Political Psychology

Other key methods include:

• Psychometric instruments: Validated questionnaire scales measuring ideological orientation, moral foundations, collective narcissism, authoritarianism, and related constructs.
• Computational text analysis: Linguistic analysis of large corpora (speeches, social media, newspapers) to detect psychological dimensions of political language over time (as in Buttrick et al., 2020, covered in Chapter 5).
• Neuroscience methods: fMRI and structural MRI used to identify neural correlates of ideological thinking (Zmigrod, 2022, covered in Chapter 6).
• Cross-cultural and cross-national research: Testing whether psychological findings replicate across cultural and national contexts — critical for claims about human universals in political psychology.

Scope and Organization of This Course

This course begins with foundational questions about how emotion and cognition shape political judgment (Chapters 2–3), moves through the moral and linguistic dimensions of political life (Chapters 4–5), examines the psychology of extremism and misinformation (Chapters 6–7), explores applied interventions to address polarization and democratic backsliding (Chapter 8), and concludes with a focused treatment of intergroup relations — collective narcissism, dehumanization, reconciliation, and political violence (Chapters 9–12). The unifying thread is the application of rigorous psychological science to pressing political problems.

Chapter 2: Emotion, Affect, and Scope Insensitivity

The Centrality of Affect in Political Judgment

Classical theories of democratic citizenship assume that citizens form political preferences by gathering information, weighing evidence, and calculating which policies best serve their interests. Decades of research in political psychology and behavioral economics have complicated this picture. Human judgment is not primarily deliberative — it is primarily affective. People feel their way through political choices before they reason about them, and emotion often determines the direction of reasoning rather than the reverse.

Scope Insensitivity and Psychic Numbing

Paul Slovic’s 2007 paper, “If I Look at the Mass I Will Never Act,” addresses one of the most disturbing implications of affective cognition for political life: human emotional and moral responses to mass suffering do not scale with the number of victims. This is scope insensitivity — the finding, originally from environmental valuation studies, that people will pay approximately the same amount to save 2,000 birds as to save 200,000 birds, because the emotional response to “birds in distress” reaches its ceiling quickly regardless of magnitude.

Applied to human suffering, this produces what Slovic calls psychic numbing: as the number of victims grows from one to many, the emotional response does not increase proportionally — and the data suggest it may actually decline. The graph of affect against number of victims is not linear. It is concave, flattening out near zero even as the numbers climb toward millions.

The Identified Victim Effect

The most powerful demonstration of scope insensitivity is the identified victim effect: a single, named, photographed individual elicits dramatically more charitable donations than statistical descriptions of thousands of victims. Slovic cites studies showing that:

• Donors gave more to help “Rokia,” a seven-year-old Malian child whose photograph and story were provided, than to help “8 million children facing hunger in southern Africa.”
• Adding statistical context to Rokia’s story — informing donors that Rokia was one of millions — reduced donations compared to the Rokia-alone condition.

The identified victim functions as a cognitive anchor for empathy. Once that anchor is provided, adding statistical information about a larger population does not add empathy — it dilutes the individual’s vividness and shifts processing from affective to analytic modes that are less motivating for charitable action.

Collapse of Compassion

Slovic introduces the phrase collapse of compassion to describe a related phenomenon: adding more victims to a single victim’s story actually reduces emotional response. In one study, respondents shown two children in need gave less per child than respondents shown one child alone. Emotional engagement triggered by a single person cannot be doubled or tripled — it diffuses rather than amplifies as the group grows.

This has direct implications for humanitarian advocacy. The instinct of advocates is to communicate scale — to impress donors and policymakers with the enormity of suffering. Slovic’s research suggests this is psychologically counterproductive: the enormity of the numbers activates numbing precisely because large numbers signal a problem that exceeds individual imagining.

Implications for Genocide and Political Violence

Perhaps the most disturbing application of psychic numbing is to the psychology of genocide response. Slovic argues that the international community’s repeated failure to intervene in atrocities — from the Holocaust to Rwanda to Darfur — is not solely a failure of political will or strategic interest. It is partly a systematic feature of how human psychology processes large-scale suffering. “Never Again” may be structurally undermined by the very cognitive architecture it relies on to motivate action.

Effective advocacy against atrocities may need to work against the natural tendency toward abstraction, by re-individualizing victims — creating identified proxies who can function as emotional entry points for the mass. This strategy works with the psychology of affect rather than against it.

Chapter 3: Political Ideology

Defining Ideology

In political science, ideology typically refers to a coherent system of beliefs about how society should be organized — covering economic policy, social policy, the role of the state, and fundamental values. The left-right or liberal-conservative dimension is the dominant organizing axis in most Western democracies, though this single dimension cannot capture the full complexity of political belief systems.

Political psychologists ask a deeper question: why do individuals end up on one side of the ideological spectrum or the other? Jost’s (2009) answer is that political ideology is not merely a set of policy preferences but a motivational system — a coherent set of psychological dispositions that orient people toward particular political worldviews through what he calls elective affinities.

Psychological Foundations of Left-Right Ideology

Jost synthesizes a large body of research identifying stable psychological differences between people who identify as liberal versus conservative:

Need for Cognitive Closure (NCC): Conservatives score higher on validated measures of NCC — the desire for clear answers, certainty, order, and closure on ambiguous questions. High-NCC individuals are uncomfortable with ambiguity and motivated to reach and maintain stable cognitive positions. This predicts preference for tradition (known to work), resistance to social change (introduces uncertainty), and acceptance of hierarchy (provides social structure and order).

Threat sensitivity: Conservatives are more responsive to environmental threats — both physical and symbolic. In high-threat environments, conservative attitudes (preference for strong security, in-group solidarity, familiar social arrangements) are especially salient. Experimental manipulation of threat salience has been shown to temporarily shift political attitudes in a conservative direction even among liberal participants.

System justification motivation: People are motivated to perceive existing social arrangements as fair and legitimate — a tendency Jost calls system justification. This motivation is stronger, on average, among conservatives, predicting greater acceptance of social inequality as natural or deserved rather than unjust.

Integration with dual-process cognition: Conservative ideology is associated with greater reliance on intuitive, affective, heuristic processing (System 1 in Kahneman’s framework). Liberal ideology is associated with greater reliance on analytic, reflective processing (System 2). This is consistent with studies showing conservatives are less likely to override initial intuitions in cognitive reflection tasks.

Political Monoculture in Psychological Science

A methodological problem raised by Inbar and Lammers (2012) cuts to the heart of how political psychology is practiced: the field itself is politically homogeneous in a way that may compromise its scientific credibility. Their survey of members of the Society for Personality and Social Psychology (SPSP) found that self-identified conservatives constituted approximately 6% of the sample, with liberals outnumbering conservatives roughly 14:1. This is far more skewed than either the general population or other academic disciplines.

The consequences Inbar and Lammers identify are methodologically serious:

• Topic selection bias: Socially liberal research topics receive more systematic attention than liberal-critical topics. There is no obvious scientific reason for this asymmetry.
• Conceptual framing bias: Key constructs — “prejudice,” “authoritarianism,” “closed-mindedness” — may be defined in ways that embed liberal assumptions. The concept of “political prejudice” has historically been studied asymmetrically, with more attention to conservative prejudice than to equivalent liberal prejudice.
• Peer review bias: A substantial minority of respondents (including many liberals) admitted they would rate a conservative job candidate less favorably than an equivalent liberal candidate, suggesting ideological homogeneity partly perpetuates itself through social exclusion.
• Publication bias: Research showing liberal groups in a negative light may face higher scrutiny and lower publication rates, generating a systematic file-drawer problem.

Inbar and Lammers argue that addressing this requires explicit institutional commitment to ideological diversity in hiring, grant review, and the study of political psychology’s own biases — making the field’s self-examination a scientific priority, not merely a political one.

Chapter 4: Moral Foundations and Political Disagreement

The Limits of Single-Axis Moral Theory

Much of Western moral philosophy since the Enlightenment has sought a unifying principle of morality — whether the maximization of welfare (utilitarianism), respect for rational autonomous persons (Kantian deontology), or virtue (Aristotelian ethics). Haidt and colleagues argue that this philosophical universalizing tendency maps onto a specifically liberal moral sensibility: a focus on harm prevention and fairness as the only genuine moral concerns, with other moral intuitions dismissed as mere bias or cultural convention.

Moral Foundations Theory (MFT), developed by Haidt, Graham, and colleagues, rejects this. It proposes that human morality rests on multiple distinct psychological systems — foundations — each with evolutionary origins, each present across cultures, and each weighting moral and political judgments differently across individuals.

The Five Moral Foundations

Liberal and Conservative Moral Palates

The central empirical finding from Haidt et al.’s (2009) large-scale survey research using the Moral Foundations Questionnaire (MFQ) is a systematic difference in how liberals and conservatives weight these foundations:

• Liberals score high on Care and Fairness and low on Loyalty, Authority, and Sanctity. Their moral universe is organized primarily around preventing harm and ensuring justice.
• Conservatives score moderately high across all five foundations. They share liberal concerns about care and fairness but also heavily weight loyalty, authority, and purity.

Haidt describes this as a difference between a “narrow moral palate” (liberals) and a “full moral palate” (conservatives) — a framing deliberately designed to challenge the implicit assumption that liberal moral foundations are complete and others are mere bias or irrationality. Cross-cultural evidence from the MFQ supports the evolutionary universality claim: the five foundations appear across cultures, even as their relative weighting varies.

Implications for Political Communication

MFT has direct implications for political persuasion across ideological divides. Haidt argues that political communication typically fails because advocates frame arguments in their own moral vocabulary rather than the audience’s. When a liberal argues for environmental protection by citing harm to ecosystems, this resonates with Care/Harm foundations but leaves Authority, Loyalty, and Sanctity untouched — and these are precisely the foundations that conservative audiences weight most.

Moral translation — reframing arguments in the moral vocabulary of the target audience — can substantially improve cross-ideological persuasion. Framing immigration policy in terms of national loyalty and heritage (Loyalty foundation) or framing conservation as maintaining the purity of the natural world (Sanctity foundation) increases conservative support compared to equivalent harm-focused framings.

Chapter 5: Political Rhetoric and Language

The Linguistic Turn in Political Psychology

Language is the medium of political life — the vehicle through which ideology is transmitted, coalitions are formed, enemies are defined, and moral worlds are constructed. Political psychology has increasingly turned to systematic linguistic analysis, using computational methods to detect psychological patterns in large text corpora that would be invisible to human readers scanning individual documents.

Historical Change in American Political Rhetoric

Buttrick et al. (2020) analyze a large corpus of American political texts — presidential speeches, congressional records, party platforms — spanning from the late eighteenth century to the early twenty-first, using the Linguistic Inquiry and Word Count (LIWC) system to measure psychological dimensions of political language over time.

Three major shifts emerge from Buttrick et al.’s analysis:

1. Rise of psychological language. Political texts increasingly use first-person singular pronouns (I, me, my) and emotion words, centering the subjective experiences of the speaker. This represents a shift from a public/civic framing of political issues to a personal/psychological framing. Political rhetoric increasingly presents positions as expressions of personal experience and feeling rather than impersonal civic obligation.

2. Decline of moral duty language. Language emphasizing obligation, duty, and civic responsibility — what political philosophers call deontological civic language — has declined relative to language emphasizing rights, identity, and personal experience. This mirrors broader cultural shifts in moral discourse described by sociologists, including Robert Bellah’s analysis of American “expressive individualism.”

3. Rising us/them distinctions. Language creating and emphasizing in-group/out-group boundaries has increased substantially over the past several decades, tracking the rise of affective polarization documented by survey methods. The linguistic record provides independent historical evidence of psychological shifts that corroborate and extend survey-based polarization research.

Historical Trauma and Intergroup Language

Bilewicz (2022) approaches political language from a different angle: the way that historical trauma — collective experiences of past atrocities, persecution, and defeat — shapes how groups talk about and relate to each other in the present. Historical trauma is not merely historical context; it is a psychologically active representation transmitted across generations that structures contemporary threat perception, intergroup communication, and political identity.

Transmission mechanisms include parental socialization (children absorbing parents’ trauma narratives and threat perceptions); postmemory (the vivid internalization of others’ traumatic memories as quasi-personal memories, identified in Holocaust survivor families); and cultural practices (ceremonies, commemorations, national holidays, and education systems that keep trauma narratives salient).

A particularly important dynamic is competitive victimhood — the tendency for groups with strong historical trauma identities to compete over whose suffering was more severe or morally significant. This is not merely a historical dispute; it is a psychological conflict over moral standing, acknowledgment, and compensation. Competitive victimhood creates a zero-sum dynamic in which acknowledging the other group’s suffering feels threatening to one’s own group’s moral status — making reconciliation especially difficult.

For political language specifically, historical trauma means that groups interpret contemporary rhetoric through the lens of past catastrophes: minor intergroup frictions are read as harbingers of persecution, ambiguous statements are interpreted as threats, and political opponents are cast in the roles of historical persecutors. Effective intergroup communication must account for how trauma frames the reception of language.

Chapter 6: The Psychology of Ideological Thinking and Extremism

Ideology as Content vs. Ideology as Style

Most research on political ideology focuses on content — what people believe, which policies they support, where they fall on left-right scales. Zmigrod’s (2022) research program takes a different approach: studying ideology as a cognitive style — the how, rather than the what, of political belief.

The central claim is that ideological thinking — characterized by rigidity, internal coherence, and resistance to disconfirmation — is associated with a domain-general cognitive style that cuts across ideological content. The authoritarian nationalist and the revolutionary socialist may believe entirely different things, but if both hold their beliefs with the same rigid certainty and resist updating in response to evidence, they share a common psychological profile.

Cognitive Measures of Ideological Thinking

Zmigrod and colleagues use standard cognitive psychology paradigms to measure cognitive flexibility in ideological and non-ideological individuals:

• Task-switching flexibility: High-ideology individuals show reduced ability to shift between task rules when cue changes require switching cognitive sets.
• Probabilistic reversal learning: When reward contingencies reverse, high-ideology individuals update more slowly, showing perseverative responding.
• Working memory updating: High-ideology individuals show weaker ability to discard outdated information from working memory in dynamic updating tasks.
• Cognitive inhibition: High-ideology individuals show stronger prepotent responses and weaker inhibitory control in go/no-go and stop-signal paradigms.

Critically, these are not measures of intelligence. They are measures of cognitive flexibility, measured on tasks with no ideological content whatsoever. The finding is that ideological commitment in the political domain correlates with cognitive rigidity in purely abstract cognitive tasks.

Neural Correlates of Ideological Thinking

Brain imaging studies reviewed by Zmigrod find structural and functional differences associated with ideological thinking in regions implicated in cognitive control:

• Prefrontal cortex: Regions supporting flexible goal-directed behavior and cognitive updating show reduced activation and, in structural analyses, reduced gray matter volume in high-ideology individuals.
• Striatum: Reward prediction and habit formation circuits that support rigid, habitual responding show differential engagement.
• Anterior cingulate cortex: A region critical for conflict detection and behavioral adjustment shows reduced sensitivity to conflict signals in ideological individuals — less responsiveness to cues that current behavior needs updating.

Cross-Ideological Generality

A critical feature of Zmigrod’s findings is that they hold across ideological content. Both extreme left and extreme right individuals score higher on cognitive rigidity measures than moderates. Religious fundamentalism and secular dogmatism show similar cognitive profiles. This cross-ideological generality is what supports the domain-general cognitive style interpretation: the feature that unites ideologues across the spectrum is not what they believe but how they hold beliefs.

Implications for Radicalization

The domain-general cognitive style model implies that radicalization is not purely a content problem — not just a matter of individuals being exposed to extremist ideas. It partly reflects a cognitive disposition toward rigidity that may precede content. Interventions aimed at reducing radicalization might usefully target cognitive flexibility through training, environmental design, or educational approaches that cultivate deliberation and tolerance of ambiguity, in addition to content-specific counter-narratives.

Chapter 7: Misinformation and Fake News

The Stakes

Misinformation — false or misleading information spread regardless of intent — has emerged as one of the most actively researched problems in political psychology since 2016. False beliefs about electoral fraud, vaccine safety, climate change, and political opponents affect real behavior: they shape votes, fuel political violence, undermine public health compliance, and erode trust in democratic institutions. Understanding the psychology of misinformation is both a scientific and a civic priority.

Two Models: Motivated Reasoning vs. Inattention

The dominant framework in political misinformation research has been motivated reasoning: people believe false news because it confirms their partisan identities. On this view, ideologically consistent misinformation penetrates political cognition because critical thinking is strategically disabled — people want to believe information favoring their side and resist information that challenges it. This implies that corrections will bounce off ideologically motivated belief.

Pennycook and Rand (2021) challenge this view with the inattention hypothesis:

Several lines of evidence support this view:

1. People can tell. When directly asked whether a headline is accurate — independent of whether they would share it — people correctly identify true headlines at rates well above chance, including for politically concordant misinformation. If motivated reasoning were dominant, people should be unable to accurately evaluate content aligning with their political identity. They mostly can.

2. The accuracy nudge effect. Simply asking people “Is this headline accurate?” before sharing decisions significantly reduces misinformation sharing — including politically concordant misinformation. This works by making accuracy goals salient. If motivated reasoning were the primary driver, this brief prompt should not penetrate partisan defenses. But it does.

3. Analytic thinking predicts less susceptibility, across parties. Individuals who score higher on cognitive reflection tests are less susceptible to misinformation regardless of whether the misinformation is politically concordant or discordant. This is inconsistent with motivated reasoning, which predicts that analytic thinkers would be better at rationalizing their preferred beliefs, not better at rejecting them.

Interventions: Pre-bunking and Accuracy Nudges

Kozyreva et al. (2024) provide a comprehensive review and classification of misinformation interventions, assessing the evidence base for each:

Prebunking/inoculation: Drawing on McGuire’s (1961) psychological inoculation theory, prebunking exposes people to weakened doses of misinformation techniques — emotional manipulation, false experts, conspiracy logic — before they encounter real misinformation using those techniques. The theoretical mechanism is that forewarned individuals build cognitive “antibodies” that help them recognize and resist the techniques when encountered in the wild. Field studies find that even brief inoculation interventions — including a browser-based game called Bad News — confer measurable resistance to real-world misinformation.

Accuracy nudges: As demonstrated by Pennycook and Rand, accuracy-salience prompts reduce sharing. At the scale of a social media platform with hundreds of millions of users, even a small per-nudge effect size becomes a massive absolute reduction in misinformation sharing.

Labeling: Warning labels applied by fact-checkers help, but carry a critical limitation: the implied truth effect. Unlabeled content appears more credible because users infer that fact-checkers would have labeled it if false. Since fact-checkers can review only a small fraction of content, this inference is frequently wrong — labeling may inadvertently raise the perceived credibility of unlabeled misinformation.

Platform design: Structural changes to platform architecture — friction before sharing, requiring reading before sharing, reducing algorithmic amplification of emotionally engaging content — can reduce misinformation spread. These face significant commercial headwinds since emotional content drives engagement and engagement drives advertising revenue.

Chapter 8: Interventions for Democratic Strengthening

The Problem: Affective Polarization and Democratic Backsliding

Contemporary liberal democracies face two interrelated problems that political psychology can potentially address. Affective polarization — intense partisan dislike and distrust that goes beyond genuine policy disagreement — has grown substantially in the United States and other democracies since the 1980s. This is distinct from ideological polarization (actual policy divergence), which has grown more modestly. Many people hold increasing hostility toward the opposing party without large changes in their own policy views.

Alongside affective polarization, democratic commitments — support for democratic norms like accepting electoral results, protecting minority rights, and constraining executive power — have weakened in some populations. These problems are related but distinct, and may require targeted interventions.

The Megastudy Approach

Voelkel et al. (2024) deployed a megastudy design — simultaneously testing 25 distinct interventions in a large, nationally representative sample — allowing direct comparison of effect sizes across interventions under identical conditions. This is methodologically superior to comparing across individual RCTs conducted at different times with different samples.

The top-performing interventions fell into three categories:

1. Appeals to democratic norms: Interventions communicating that most Americans — across party lines — value democratic norms reduced antidemocratic attitudes and support for norm violations. The mechanism appears to be social norm correction: people systematically overestimate how many fellow citizens support antidemocratic behavior. Correcting this misperception shifts behavior toward the more pro-democratic real norm.

2. Cross-partisan perspective-taking: Brief videos showing ordinary members of the opposing party expressing mainstream, non-extremist views reduced partisan animosity by humanizing out-group members. This leverages contact theory principles — exposure to out-group heterogeneity undermines categorical stereotypes.

3. Correcting misperceptions about opponent extremity: People systematically overestimate how extreme the typical member of the opposing party is. Providing accurate, representative information about the opposing party’s composition and views reduced partisan hostility, with some effects lasting up to a month.

Less effective interventions included appeals to shared American identity and generic empathy exercises, which sometimes backfired by activating rather than bridging partisan identities. Modest absolute effect sizes across interventions underscore that psychological interventions are tools, not solutions: they can contribute at the margins but cannot substitute for structural and institutional reforms.

Affective Polarization: A Review of Interventions

Hartman et al. (2022) review 60+ studies of affective polarization interventions, organizing effective approaches into three levels:

Thoughts-level interventions target beliefs and perceptions about political opponents. The most robustly effective single approach is misperception correction — providing accurate information about the actual views and composition of the opposing party. Reported effects include a 34% reduction in support for political violence and a 44% reduction in willingness to engage in partisan discrimination, with effects sustained for at least a month in some studies.

Relationships-level interventions create positive contact between partisans: structured dialogue programs, common humanity framing that highlights within-group diversity of the out-party, and cross-partisan friendship-formation initiatives. These generally show smaller or more variable effects.

Institutions-level interventions include electoral reforms (ranked-choice voting, open primaries) and media reforms that structurally reduce incentives for affective polarization. These operate on longer timescales but may produce more durable change.

Chapter 9: Collective Narcissism and Intergroup Conflict

Group Identity and Its Discontents

Social identity theory (Tajfel & Turner, 1979) established that group membership is a central source of self-esteem and that people are motivated to view their in-groups favorably. Substantial research shows that positive group identification — genuine pride and belonging — does not inherently predict out-group hostility. People can love their groups without hating others.

Golec de Zavala and Lantos (2020) introduce a conceptually distinct form of group attachment — collective narcissism — that reliably does predict out-group hostility and differs from positive group identification in theoretically important ways.

Measuring Collective Narcissism

The Collective Narcissism Scale developed by Golec de Zavala captures the “unrecognized greatness” component with items such as “My group deserves special treatment,” “I will never be satisfied until my group gets the recognition it deserves,” and “It really bothers me when outsiders criticize my group.” This scale correlates only modestly with positive group identification scales, confirming discriminant validity — these are measuring different constructs.

Predictive Validity

Collective narcissism uniquely predicts, controlling for positive group identification:

• Conspiracy beliefs about out-group threats: Including anti-Semitic conspiracy theories, anti-immigrant threat beliefs, and beliefs about hostile foreign interference.
• Support for aggressive policies: Including military action, punitive immigration policies, and economic sanctions.
• Hypersensitivity to perceived slights: Minor ambiguous actions by out-groups are perceived as deliberate insults requiring strong responses.
• In-group overexclusion: Expelling or rejecting in-group members who fail to conform to group ideology — a sign of defensive rather than secure group attachment.

The Frustrated Entitlement Mechanism

The psychological engine of collective narcissism is frustrated entitlement — not high self-esteem about the group but insecurity and need for external validation of a greatness felt to be unrecognized. Collective narcissists are not simply proud of their group; they feel their group is not getting the respect it deserves from outsiders, and this unmet entitlement generates chronic hostility toward groups perceived as dismissing, ignoring, or undermining their group’s status.

This mechanism has important implications for intervention. Direct arguments against the group’s exceptionalist beliefs are likely to backfire. Interventions that address the underlying status insecurity — by providing legitimate avenues for group status affirmation — may be more effective than those that directly challenge collective narcissistic beliefs.

Chapter 10: Dehumanization in Conflict

What Is Dehumanization?

Dehumanization — denying the full human status of other people — is one of the most potent psychological mechanisms enabling mass violence, atrocity, and sustained intergroup conflict. If the enemy is not fully human, the moral constraints against harming humans do not apply. Dehumanization has been documented as a precursor to genocide, torture, and ethnic cleansing across many historical cases.

Research distinguishes between subtle dehumanization (denying out-groups uniquely human emotions like nostalgia or guilt while accepting they share basic emotions) and blatant dehumanization (explicitly placing out-groups at lower evolutionary status). Bruneau and Kteily (2017) focus on the latter.

The Ascent Measure

Bruneau and Kteily use an evolutionarily-grounded measure of blatant dehumanization: the Ascent scale, in which respondents rate in-group and out-group members on a figure depicting evolutionary ascent from a hunched, ape-like figure to an upright Homo sapiens. Lower ratings place the group closer to “animal”; higher ratings place them closer to “fully evolved human.” This operationalization is deliberately unambiguous — it measures the crudest, most explicit form of dehumanization.

Symmetric Dehumanization in Asymmetric Warfare

The key finding of Bruneau and Kteily’s (2017) study of the 2014 Israel-Gaza conflict is striking: despite dramatic asymmetry in military power, economic resources, and political rights, both Israelis and Palestinians dehumanized the other at nearly identical levels — approximately 38–40 points lower on the 100-point Ascent scale than their in-group ratings, with both placing the out-group below the scale midpoint (closer to “animal” than “fully human” in absolute terms).

This challenges frameworks predicting dehumanization to be primarily a tool of the powerful against the powerless. The disadvantaged group (Palestinians, by virtually all objective metrics of power) dehumanized the more powerful group as strongly as the reverse. Symmetric dehumanization emerged despite asymmetric power.

Furthermore, approximately half of each sample showed very large dehumanization effects, indicating that blatant dehumanization is not a fringe phenomenon in conflict-affected populations. It is widespread — a majority behavior, not an extremist one.

Unique Predictive Validity

Above and beyond general out-group hostility, ideology, and group identification, dehumanization uniquely predicts:

• Less hope for peace and less willingness to negotiate
• Less guilt about the in-group’s harmful actions in the conflict
• Greater acceptance of collective punishment and civilian casualties
• Greater support for military escalation and aggressive policy
• Stronger hostility and aggression orientation

These effects hold in both conflict parties, supporting the conclusion that dehumanization is a distinct psychological force that independently drives harmful behavior — not merely an epiphenomenon of general hostility.

Chapter 11: Reconciliation and Intergroup Healing

The Difficulty of Reconciliation

Reconciliation — the process by which groups that have harmed each other move toward genuine peaceful coexistence — is one of the most psychologically demanding achievements in human social life. Simply stopping violence does not produce reconciliation; many post-conflict societies maintain structural peace while sustaining deep mutual hostility, fear, and moral outrage. Understanding the psychology of reconciliation requires understanding what conflict does to each party’s psychological identity.

The Needs-Based Model

Shnabel and Nadler’s (2015) needs-based model of reconciliation provides a systematic account of why the psychological damage done by conflict differs by role, and why this asymmetry is critical for designing effective reconciliation interventions.

Asymmetric Interventions

The core prescription of the needs-based model is that effective reconciliation requires asymmetric interventions — different messages for victims and perpetrators:

• Victims need empowerment messages: communications that restore their sense of agency, efficacy, and strength. “You are capable. You are resilient. You can protect yourself.”
• Perpetrators need acceptance messages: communications that restore their moral image. “We acknowledge your humanity. You can make amends. You can be forgiven.”

The experimental evidence is compelling. In studies with Israeli and Palestinian participants, and with German and Jewish participants in the context of the Holocaust, participants from perpetrator groups showed increased reconciliation willingness after receiving acceptance messages (which restored threatened moral image), while victim-group participants showed increased reconciliation willingness after empowerment messages (which restored threatened agency).

Critically, giving each side the other side’s needed message — giving acceptance messages to victims, or empowerment messages to perpetrators — had no positive effect and sometimes backfired. The specificity of psychological need to conflict role is a precise prescription for how reconciliation should be designed, not merely a general observation.

Cross-Conflict Generality and Extensions

The asymmetric pattern replicated across multiple historical conflicts, different national groups, and different conflict stages, suggesting that the model tracks the relational structure of the victim/perpetrator distinction rather than specific cultural features.

The model explains why well-intentioned reconciliation initiatives often misfire: symmetric gestures — both parties simultaneously expressing remorse and forgiveness — address neither side’s specific need well. Effective reconciliation must be diagnostically precise, identifying which group needs what kind of message and delivering it in ways that feel genuine rather than formulaic.

Chapter 12: Sacred Values and Political Violence

The Limits of Rational Choice in Conflict

Standard political science and economics models analyze conflict as a strategic instrument: groups weigh the costs and benefits of violent versus peaceful strategies and choose the option that best serves their interests. This rational choice framework predicts that violence support should decrease when violence is perceived as ineffective, and that material incentives can purchase compromise.

Ginges (2019) argues that these predictions fail systematically when conflicts involve sacred values — and that understanding why requires a different psychological framework.

Sacred Values and Devoted Actor Theory

Ginges introduces the concept of the devoted actor — an individual committed to a sacred cause or group as an end in itself, not as an instrument for other goods. Devoted actors do not calculate the expected utility of violence; they experience violence for the cause as morally required, regardless of whether it will succeed. Their commitment is identity-fused with the cause itself.

The Material Incentive Backfire Effect

In studies with Palestinian supporters of suicide bombing, Israeli settlers resistant to leaving the West Bank, and other groups with sacred-value commitments, Ginges finds that offering material compensation for compliance with hated policies — financial payments, land grants, improved economic conditions — not only fails to reduce opposition but often increases it.

This backfire effect occurs because material offers contaminate the sacred meaning of the stance. For a devoted actor opposing a policy on sacred grounds, an offer of money in exchange for compliance signals that the opponent views the sacred cause as merely instrumental — a bargaining chip to be bought off. This is experienced as profoundly insulting: it confirms that the opponent fails to understand what is at stake. The result is increased opposition.

Insensitivity to Efficacy

A key diagnostic signature of sacred-value reasoning is insensitivity to the perceived effectiveness of violence. If support for violence is instrumental, it should decline when violence is perceived as unlikely to succeed. If support is deontological — violence as duty — it should be insensitive to efficacy.

Ginges’ data show that support for sacred-value violence does not decline when subjects are told the violence is unlikely to succeed. This violates expected utility theory and confirms the devoted actor model: people are not supporting violence because they think it will work. They are supporting it because it is the right thing to do for the cause.

Implications for Conflict Resolution

The sacred values framework has direct implications for negotiation and conflict resolution practice:

• Conventional bargaining theory fails for sacred-value conflicts. Material trade-offs and compromise deals may be literally counterproductive by triggering the backfire effect.
• Symbolic recognition is non-optional. Negotiations must engage the moral and symbolic dimensions of the conflict — acknowledgment, apology, legitimacy recognition, validation of the other side’s sacred commitments — before or alongside material negotiations.
• Sequencing matters. Material negotiations may need to be preceded by symbolic gestures that establish genuine respect for the other side’s sacred values — not tolerance of them as obstacles, but recognition of them as real.