Partisans process policy-based and identity-based messages using dissociable neural systems.

Political partisanship is often conceived as a lens through which people view politics. Behavioral research has distinguished two types of "partisan lenses"-policy-based and identity-based-that may influence peoples' perception of political events. Little is known, however, about the mechanisms through which partisan discourse appealing to policy beliefs or targeting partisan identities operate within individuals. We addressed this question by collecting neuroimaging data while participants watched videos of speakers expressing partisan views. A "partisan lens effect" was identified as the difference in neural synchrony between each participant's brain response and that of their partisan ingroup vs. outgroup. When processing policy-based messaging, a partisan lens effect was observed in socio-political reasoning and affective responding brain regions. When processing negative identity-based attacks, a partisan lens effect was observed in mentalizing and affective responding brain regions. These data suggest that the processing of political discourse that appeals to different forms of partisanship is supported by related but distinguishable neural-and therefore psychological-mechanisms, which may have implications for how we characterize partisanship and ameliorate its deleterious impacts.

Exaggerated meta-perceptions predict intergroup hostility between American political partisans.

People's actions toward a competitive outgroup can be motivated not only by their perceptions of the outgroup, but also by how they think the outgroup perceives the ingroup (i.e., meta-perceptions). Here, we examine the prevalence, accuracy, and consequences of meta-perceptions among American political partisans. Using a representative sample (n = 1,056) and a longitudinal convenience sample (n = 2,707), we find that Democrats and Republicans equally dislike and dehumanize each other but think that the levels of prejudice and dehumanization held by the outgroup party are approximately twice as strong as actually reported by a representative sample of Democrats and Republicans. Overestimations of negative meta-perceptions were consistent across samples over time and between demographic subgroups but were modulated by political ideology: More strongly liberal Democrats and more strongly conservative Republicans were particularly prone to exaggerate meta-perceptions. Finally, we show that meta-prejudice and meta-dehumanization are independently associated with the desire for social distance from members of the outgroup party and support for policies that harm the country and flout democratic norms to favor the ingroup political party. This research demonstrates that partisan meta-perceptions are subject to a strong negativity bias with Democrats and Republicans agreeing that the shadow of partisanship is much larger than it actually is, which fosters mutual intergroup hostility.

Beliefs about social norms and racial inequalities predict variation in the early development of racial bias.

Racism remains a pervasive force around the world with widespread and well documented harmful consequences for members of marginalized racial groups. The psychological biases that maintain structural and interpersonal racism begin to emerge in early childhood, but with considerable individual variation-some children develop more racial bias than others. The present study (N = 116; 4-year-old children) provides novel insights into the developmental mechanisms underlying the emergence of racial bias by longitudinally documenting how two psychological processes-normative beliefs about interracial friendships and explanatory beliefs about racial inequalities-developmentally predict the emergence of pro-White/anti-Black racial bias during early childhood. In a 6-month, three-wave, longitudinal study, we found that 4-year-old children's beliefs that their parents and peers do not value interracial friendships predicted increased racial bias in and across time and that children's endorsement of essentialist over extrinsic explanations for racial inequalities predicted the developmental trajectory of racial bias over time. These findings suggest that children's foundational beliefs about the social world developmentally predict the emergence of racial bias in early childhood and speak to the importance of early and persistent intervention efforts targeting children's normative beliefs about interracial friendships and explanatory beliefs about racial inequalities.

Localizing Pain Matrix and Theory of Mind networks with both verbal and non-verbal stimuli.

Functional localizer tasks allow researchers to identify brain regions in each individual's brain, using a combination of anatomical and functional constraints. In this study, we compare three social cognitive localizer tasks, designed to efficiently identify regions in the "Pain Matrix," recruited in response to a person's physical pain, and the "Theory of Mind network," recruited in response to a person's mental states (i.e. beliefs and emotions). Participants performed three tasks: first, the verbal false-belief stories task; second, a verbal task including stories describing physical pain versus emotional suffering; and third, passively viewing a non-verbal animated movie, which included segments depicting physical pain and beliefs and emotions. All three localizers were efficient in identifying replicable, stable networks in individual subjects. The consistency across tasks makes all three tasks viable localizers. Nevertheless, there were small reliable differences in the location of the regions and the pattern of activity within regions, hinting at more specific representations. The new localizers go beyond those currently available: first, they simultaneously identify two functional networks with no additional scan time, and second, the non-verbal task extends the populations in whom functional localizers can be applied. These localizers will be made publicly available.

Empathic control through coordinated interaction of amygdala, theory of mind and extended pain matrix brain regions.

Brain regions in the "pain matrix", can be activated by observing or reading about others in physical pain. In previous research, we found that reading stories about others' emotional suffering, by contrast, recruits a different group of brain regions mostly associated with thinking about others' minds. In the current study, we examined the neural circuits responsible for deliberately regulating empathic responses to others' pain and suffering. In Study 1, a sample of college-aged participants (n=18) read stories about physically painful and emotionally distressing events during functional magnetic resonance imaging (fMRI), while either actively empathizing with the main character or trying to remain objective. In Study 2, the same experiment was performed with professional social workers, who are chronically exposed to human suffering (n=21). Across both studies activity in the amygdala was associated with empathic regulation towards others' emotional pain, but not their physical pain. In addition, psychophysiological interaction (PPI) analysis and Granger causal modeling (GCM) showed that amygdala activity while reading about others' emotional pain was preceded by and positively coupled with activity in the theory of mind brain regions, and followed by and negatively coupled with activity in regions associated with physical pain and bodily sensations. Previous work has shown that the amygdala is critically involved in the deliberate control of self-focused distress - the current results extend the central importance of amygdala activity to the control of other-focused empathy, but only when considering others' emotional pain.

Exposure to a media intervention helps promote support for peace in Colombia.

Whereas politicians broker peace deals, it falls to the public to embrace peace and help sustain it. The legacy of conflicts can make it difficult for people to support reconciling and reintegrating with former enemies. Here we create a five-minute media intervention from interviews we conducted with Colombian Revolutionary Armed Forces (FARC) ex-combatants in a Colombian demobilization camp and non-FARC Colombians in neighbouring communities. We show that exposure to the media intervention humanizes FARC ex-combatants and increases support for peace and reintegration. These effects persisted at least three months post-exposure, were replicated in an independent sample of non-FARC Colombians and affected both attitudes (for example, support for reintegration policies) and behaviour (for example, donations to organizations supporting ex-combatants). As predicted, the intervention's effects were mediated by changing conflict-associated cognitions-reducing the belief that ex-combatants are unwilling and unable to change-beyond affective pathways (for example, increased empathy or reduced prejudice).

Dynamics of the rapsyn scaffolding protein at the neuromuscular junction of live mice.

The efficacy of synaptic transmission depends on the maintenance of a high density of neurotransmitter receptors and their associated scaffold proteins in the postsynaptic membrane. While the dynamics of receptors has been extensively studied, the dynamics of the intracellular scaffold proteins that make up the postsynaptic density are largely unknown in vivo. Here, we focused on the dynamics of rapsyn, a protein required for the clustering and maintenance of acetylcholine receptor (AChR) density at postsynaptic sites. Using time-lapse imaging, we demonstrated that rapsyn is remarkably dynamic compared to AChRs at functional synapses, turning over 4-6 times more rapidly than AChRs. In addition we found that the rapid turnover of rapsyn is insensitive to alterations in synaptic activity, whereas AChR turnover is profoundly affected, illustrating that rapsyn and receptor dynamics are controlled by distinct mechanisms. These data indicate that individual postsynaptic components are in permanent exchange despite the overall stability of synaptic structure, which may play a role in synaptic plasticity.

Acetylcholine receptor clustering is required for the accumulation and maintenance of scaffolding proteins.

The maintenance of a high density of postsynaptic receptors is essential for proper synaptic function. At the neuromuscular junction, acetylcholine receptor (AChR) aggregation is induced by nerve-clustering factors and mediated by scaffolding proteins. Although the mechanisms underlying AChR clustering have been extensively studied, the role that the receptors themselves play in the clustering process and how they are organized with scaffolding proteins is not well understood. Here, we report that the exposure of AChRs labeled with Alexa 594 conjugates to relatively low-powered laser light caused an effect similar to chromaphore-assisted light inactivation (CALI) , which resulted in the unexpected dissipation of the illuminated AChRs from clusters on cultured myotubes. This technique enabled us to demonstrate that AChR removal from illuminated regions induced the removal of scaffolding proteins and prevented the accumulation of new AChRs and associated scaffolding proteins. Further, the dissipation of clustered AChRs and scaffold was spatially restricted to the illuminated region and had no effect on neighboring nonilluminated AChRs. These results provide direct evidence that AChRs are essential for the local maintenance and accumulation of intracellular scaffolding proteins and suggest that the scaffold is organized into distinct modular units at AChR clusters.

Intergroup Contact Reduces Dehumanization and Meta-Dehumanization: Cross-Sectional, Longitudinal, and Quasi-Experimental Evidence From 16 Samples in Five Countries.

In 16 independent samples from five countries involving ~7,700 participants, we employ a mixture of cross-sectional, longitudinal, and quasi-experimental methods to examine the effect of intergroup contact on (a) the blatant dehumanization of outgroups, and (b) the perception that outgroup members dehumanize the ingroup (meta-dehumanization). First, we conduct a meta-analysis across 12 survey samples collected from five countries regarding eight different target groups (total N = 5,388) and find a consistent effect of contact quality on dehumanization and meta-dehumanization. Second, we use a large longitudinal sample of American participants (N = 1,103) to show that quality of contact with Muslims at Time 1 predicts dehumanization of Muslims and meta-dehumanization 6 months later. Finally, we show that sustained semester-long "virtual contact" between American and Muslim college students is associated with reduced American students' (N = 487) dehumanization of, and perceived dehumanization by, Muslims.

Blatant dehumanization in the mind's eye: Prevalent even among those who explicitly reject it?

Research suggests that some people, particularly those on the political right, tend to blatantly dehumanize low-status groups. However, these findings have largely relied on self-report measures, which are notoriously subject to social desirability concerns. To better understand just how widely blatant forms of intergroup dehumanization might extend, the present article leverages an unobtrusive, data-driven perceptual task to examine how U.S. respondents mentally represent "Americans" versus "Arabs" (a low-status group in the United States that is often explicitly targeted with blatant dehumanization). Data from 2 reverse-correlation experiments (original N = 108; preregistered replication N = 336) and 7 rating studies (N = 2,301) suggest that U.S. respondents' mental representations of Arabs are significantly more dehumanizing than their representations of Americans. Furthermore, analyses indicate that this phenomenon is not reducible to a general tendency for our sample to mentally represent Arabs more negatively than Americans. Finally, these findings reveal that blatantly dehumanizing representations of Arabs can be just as prevalent among individuals exhibiting low levels of explicit dehumanization (e.g., liberals) as among individuals exhibiting high levels of explicit dehumanization (e.g., conservatives)-a phenomenon into which exploratory analyses suggest liberals may have only limited awareness. Taken together, these results suggest that blatant dehumanization may be more widespread than previously recognized and that it can persist even in the minds of those who explicitly reject it. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Attitudes towards the outgroup are predicted by activity in the precuneus in Arabs and Israelis.

The modern socio-political climate is defined by conflict between ethnic, religious and political groups: Bosnians and Serbs, Tamils and Singhalese, Irish Catholics and Protestants, Israelis and Arabs. One impediment to the resolution of these conflicts is the psychological bias that members of each group harbor towards each other. These biases, and their neural bases, are likely different from the commonly studied biases towards racial outgroups. We presented Arab, Israeli and control individuals with statements about the Middle East from the perspective of the ingroup or the outgroup. Subjects rated how 'reasonable' each statement was, during fMRI imaging. Increased activation in the precuneus (PC) while reading pro-outgroup vs. pro-ingroup statements correlated strongly with both explicit and implicit measures of negative attitudes towards the outgroup; other brain regions that were involved in reasoning about emotionally-laden information did not show this pattern.

Receptor-associated proteins and synaptic plasticity.

Changes in synaptic strength are important for synaptic development and synaptic plasticity. Most directly responsible for these synaptic changes are alterations in synaptic receptor number and density. Although alterations in receptor density mediated by the insertion, lateral mobility, removal, and recycling of receptors have been extensively studied, the dynamics and regulators of intracellular scaffolding proteins have only recently begun to be illuminated. In particular, a closer look at the receptor-associated proteins, which bind to receptors and are necessary for their synaptic localization and clustering, has revealed broader functions than previously thought and some rather unexpected thematic similarities. More than just "placeholders" or members of a passive protein "scaffold," receptor-associated proteins in every synapse studied have been shown to provide a number of signaling roles. In addition, the most recent state-of-the-art imaging has revealed that receptor-associated proteins are highly dynamic and are involved in regulating synaptic receptor density. Together, these results challenge the view that receptor-associated proteins are members of a static and stable scaffold and argue that their dynamic mobility may be essential for regulating activity-dependent changes in synaptic strength.

A collective blame hypocrisy intervention enduringly reduces hostility towards Muslims.

Hostility towards outgroups contributes to costly intergroup conflict. Here we test an intervention to reduce hostility towards Muslims, a frequently targeted outgroup. Our 'collective blame hypocrisy' intervention highlights the hypocrisy involved in the tendency for people to collectively blame outgroup but not ingroup members for blameworthy actions of individual group members. Using both within-subject and between-subject comparisons in a preregistered longitudinal study in Spain, we find that our intervention reduces collective blame of Muslims and downstream anti-Muslim sentiments relative to a matched control condition and that the effects of the intervention persist one month and also one year later. We replicate the benefits of the intervention in a second study. The effects are mediated by reductions in collective blame and moderated by individual differences in preference for consistency. Together, these data illustrate that the collective blame hypocrisy intervention enduringly reduces harmful intergroup attitudes associated with conflict escalation, particularly among those who value consistency in themselves and others.

Interventions Highlighting Hypocrisy Reduce Collective Blame of Muslims for Individual Acts of Violence and Assuage Anti-Muslim Hostility.

Collectively blaming groups for the actions of individuals can license vicarious retribution. Acts of terrorism by Muslim extremists against innocents, and the spikes in anti-Muslim hate crimes against innocent Muslims that follow, suggest that reciprocal bouts of collective blame can spark cycles of violence. How can this cycle be short-circuited? After establishing a link between collective blame of Muslims and anti-Muslim attitudes and behavior, we used an "interventions tournament" to identify a successful intervention (among many that failed). The "winning" intervention reduced collective blame of Muslims by highlighting hypocrisy in the ways individuals collectively blame Muslims-but not other groups (White Americans, Christians)-for individual group members' actions. After replicating the effect in an independent sample, we demonstrate that a novel interactive activity that isolates the psychological mechanism amplifies the effectiveness of the collective blame hypocrisy intervention and results in downstream reductions in anti-Muslim attitudes and anti-Muslim behavior.

Denying humanity: The distinct neural correlates of blatant dehumanization.

Recent behavioral work demonstrates that many people view low-status groups as less "evolved and civilized" than high-status groups. Are these people using blatant expressions of dehumanization simply to express strong dislike toward other groups? Or is blatant dehumanization a process distinct from other negative assessments? We tested these competing hypotheses using functional neuroimaging. Participants judged 10 groups (e.g., Europeans, Muslims, rats) on four scales: blatant dehumanization, dislike, dissimilarity and perceived within-group homogeneity. Consistent with expectations, neural responses when making ratings of dehumanization diverged from those when judging the same targets on the other related dimensions. Specifically, we found regions in the left inferior parietal cortex (IPC) and left inferior frontal cortex (IFC) that were selectively parametrically modulated by dehumanization ratings. The pattern of responses in the left IFC was also consistent with animalistic dehumanization: high responses to low-status human groups and animals, and lower responses to high-status human groups. By contrast, a region in the posterior cingulate cortex was parametrically sensitive specifically to liking. We therefore demonstrate a double dissociation between brain activity associated with judgments of blatant dehumanization and judgments of dislike. (PsycINFO Database Record

The enemy as animal: Symmetric dehumanization during asymmetric warfare.

Historically, dehumanization has enabled members of advantaged groups to 'morally disengage' from disadvantaged group suffering, thereby facilitating acts of intergroup aggression such as colonization, slavery and genocide. But is blatant dehumanization exclusive to those at the top 'looking down', or might disadvantaged groups similarly dehumanize those who dominate them? We examined this question in the context of intergroup warfare in which the disadvantaged group shoulders a disproportionate share of casualties and may be especially likely to question the humanity of the advantaged group. Specifically, we assessed blatant dehumanization in the context of stark asymmetric conflict between Israelis (Study 1; N = 521) and Palestinians (Study 2; N = 354) during the 2014 Gaza war. We observed that (a) community samples of Israelis and Palestinians expressed extreme (and comparable) levels of blatant dehumanization, (b) blatant dehumanization was uniquely associated with outcomes related to outgroup hostility for both groups, even after accounting for political ideologies known to strongly predict outgroup aggression, and (c) the strength of association between blatant dehumanization and outcomes was similar across both groups. This study illuminates the striking potency and symmetry of blatant dehumanization among those on both sides of an active asymmetric conflict.

Backlash: The Politics and Real-World Consequences of Minority Group Dehumanization.

Research suggests that members of advantaged groups who feel dehumanized by other groups respond aggressively. But little is known about how meta-dehumanization affects disadvantaged minority group members, historically the primary targets of dehumanization. We examine this important question in the context of the 2016 U.S. Republican Primaries, which have witnessed the widespread derogation and dehumanization of Mexican immigrants and Muslims. Two initial studies document that Americans blatantly dehumanize Mexican immigrants and Muslims; this dehumanization uniquely predicts support for aggressive policies proposed by Republican nominees, and dehumanization is highly associated with supporting Republican candidates (especially Donald Trump). Two further studies show that, in this climate, Latinos and Muslims in the United States feel heavily dehumanized, which predicts hostile responses including support for violent versus non-violent collective action and unwillingness to assist counterterrorism efforts. Our results extend theorizing on dehumanization, and suggest that it may have cyclical and self-fulfilling consequences.

Parochial Empathy Predicts Reduced Altruism and the Endorsement of Passive Harm.

Empathic failures are common in hostile intergroup contexts; repairing empathy is therefore a major focus of peacebuilding efforts. However, it is unclear which aspect of empathy is most relevant to intergroup conflict. Although trait empathic concern predicts prosociality in interpersonal settings, we hypothesized that the best predictor of meaningful intergroup attitudes and behaviors might not be the general capacity for empathy (i.e., trait empathy), but the difference in empathy felt for the in-group versus the out-group, or "parochial empathy." Specifically, we predicted that out-group empathy would inhibit intergroup harm and promote intergroup helping, whereas in-group empathy would have the opposite effect. In three intergroup contexts-Americans regarding Arabs, Hungarians regarding refugees, Greeks regarding Germans-we found support for this hypothesis. In all samples, in-group and out-group empathy had independent, significant, and opposite effects on intergroup outcomes, controlling for trait empathic concern.

Giving the Underdog a Leg Up: A Counternarrative of Nonviolent Resistance Improves Sustained Third-Party Support of a Disempowered Group.

In the current work, we experimentally examined the effect of exposure to a narrative of nonviolent resistance on third-party attitudes toward and support for a disempowered group involved in asymmetric conflict. Across three experiments, we found that Americans exposed to a brief video about Palestinian nonviolent resistance consistently registered more favorable attitudes toward Palestinians than people who watched a film trailer either unrelated to the Israeli-Palestinian conflict or a trailer to a Palestinian-made film about sympathetic Palestinians violently opposing Israelis. Americans' attitudes toward Palestinians and behavior supporting Palestinian collective action persisted weeks after exposure to nonviolent resistance and were mediated by decreased perceptions that Palestinians are inherently violent. Importantly, positive attitudes toward Palestinians did not result in increased negativity toward Israelis. These data show that exposure to nonviolent resistance can have lasting effects on third-party attitudes and behavior toward an underdog/disempowered group, without driving partisanship.