Bruneau, Emile

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Now showing 1 - 10 of 18
  • Publication
    They See Us as Less Than Human: Metadehumanization Predicts Intergroup Conflict via Reciprocal Dehumanization
    (2016-03-01) Kteily, Nour; Hodson, Gordon; Bruneau, Emile
    Although the act of dehumanizing an outgroup is a pervasive and potent intergroup process that drives discrimination and conflict, no formal research has examined the consequences of being dehumanized by an outgroup—that is, “metadehumanization.” Across 10 studies (N = 3,440) involving several real-world conflicts spanning 3 continents, we provide the first empirical evidence that metadehumanization (a) plays a central role in outgroup aggression that is (b) mediated by outgroup dehumanization, and (c) distinct from metaprejudice. Studies 1a and 1b demonstrate experimentally that Americans who learn that Arabs (Study 1a) or Muslims (Study 1b) blatantly dehumanize Americans are more likely to dehumanize that outgroup in return; by contrast, experimentally increasing outgroup dehumanization did not increase metadehumanization (Study 1c). Using correlational data, Study 2 documents indirect effects of metadehumanization on Americans’ support for aggressive policies toward Arabs (e.g., torture) via Arab dehumanization. In the context of Hungarians and ethnic minority Roma, Study 3 shows that the pathway for Hungarians from metadehumanization to aggression through outgroup dehumanization holds controlling for outgroup prejudice. Study 4 examines Israelis’ metaperceptions with respect to Palestinians, showing that: (a) feeling dehumanized (i.e., metadehumanization) is distinct from feeling disliked (i.e., metaprejudice), and (b) metadehumanization uniquely influences aggression through outgroup dehumanization, controlling for metaprejudice. Studies 5a and 5b explore Americans’ metaperceptions regarding ISIS and Iran. We document a dehumanization-specific pathway from metadehumanization to aggressive attitudes and behavior that is distinct from the path from metaprejudice through prejudice to aggression. In Study 6, American participants learning that Muslims humanize Americans (i.e., metahumanization) humanize Muslims in turn. Finally, Study 7 experimentally contrasts metadehumanization and metahumanization primes, and shows that resulting differences in outgroup dehumanization are mediated by (a) perceived identity threat, and (b) a general desire to reciprocate the outgroup’s perceptions of the ingroup. In summary, our research outlines how and why metadehumanization contributes to cycles of ongoing violence and animosity, providing direction for future research and policy.
  • Publication
    The Ascent of Man: Theoretical and Empirical Evidence for Blatant Dehumanization
    (2015-11-01) Kteily, Nour; Bruneau, Emile; Waytz, Adam; Cotterill, Sarah
    Dehumanization is a central concept in the study of intergroup relations. Yet although theoretical and methodological advances in subtle, “everyday” dehumanization have progressed rapidly, blatant dehumanization remains understudied. The present research attempts to refocus theoretical and empirical attention on blatant dehumanization, examining when and why it provides explanatory power beyond subtle dehumanization. To accomplish this, we introduce and validate a blatant measure of dehumanization based on the popular depiction of evolutionary progress in the “Ascent of Man.” We compare blatant dehumanization to established conceptualizations of subtle and implicit dehumanization, including infrahumanization, perceptions of human nature and human uniqueness, and implicit associations between ingroup–outgroup and human–animal concepts. Across 7 studies conducted in 3 countries, we demonstrate that blatant dehumanization is (a) more strongly associated with individual differences in support for hierarchy than subtle or implicit dehumanization, (b) uniquely predictive of numerous consequential attitudes and behaviors toward multiple outgroup targets, (c) predictive above prejudice, and (d) reliable over time. Finally, we show that blatant—but not subtle—dehumanization spikes immediately after incidents of real intergroup violence and strongly predicts support for aggressive actions like torture and retaliatory violence (after the Boston Marathon bombings and Woolwich attacks in England). This research extends theory on the role of dehumanization in intergroup relations and intergroup conflict and provides an intuitive, validated empirical tool to reliably measure blatant dehumanization.
  • Publication
    Parochial Empathy Predicts Reduced Altruism and the Endorsement of Passive Harm
    (2017-11-01) Bruneau, Emile; Cikara, Mina; Saxe, Rebecca
    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.
  • Publication
    The Dynamics of Recycled Acetylcholine Receptors at the Neuromuscular Junction in vivo
    (2006-01-01) Bruneau, Emile; Akaaboune, Mohammed
    At the peripheral neuromuscular junction (NMJ), a significant number of nicotinic acetylcholine receptors (AChRs) recycle back into the postsynaptic membrane after internalization to intermingle with not-yet-internalized `pre-existing' AChRs. However, the way in which these receptor pools are maintained and regulated at the NMJ in living animals remains unknown. Here, we demonstrate that recycled receptors in functional synapses are removed approximately four times faster than pre-existing receptors, and that most removed recycled receptors are replaced by new recycled ones. In denervated NMJs, the recycling of AChRs is significantly depressed and their removal rate increased, whereas direct muscle stimulation prevents their loss. Furthermore, we show that protein tyrosine phosphatase inhibitors cause the selective accumulation of recycled AChRs in the peri-synaptic membrane without affecting the pre-existing AChR pool. The inhibition of serine/threonine phosphatases, however, has no effect on AChR recycling. These data show that recycled receptors are remarkably dynamic, and suggest a potential role for tyrosine dephosphorylation in the insertion and maintenance of recycled AChRs at the postsynaptic membrane. These findings may provide insights into long-term recycling processes at less accessible synapses in the central nervous system in vivo.
  • Publication
    Dynamics of the Rapsyn Scaffolding Protein at the Neuromuscular Junction of Live Mice
    (2010-01-01) Bruneau, Emile; Akaaboune, Mohammed
    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.
  • Publication
    Identification of Nicotinic Acetylcholine Receptor Recycling and Its Role inn Maintaining Receptor Density at the Neuromuscular Junction In Vivo
    (2005-10-01) Bruneau, Emile; Sutter, David; Hume, Richard I; Akaaboune, Mohammed
    In the CNS, receptor recycling is critical for synaptic plasticity; however, the recycling of receptors has never been observed at peripheral synapses. Using a novel imaging technique, we show here that nicotinic acetylcholine receptors (AChRs) recycle into the postsynaptic membrane of the neuromuscular junction. By sequentially labeling AChRs with biotin-bungarotoxin and streptavidin-fluorophore conjugates, we were able to distinguish recycled, preexisting, and new receptor pools at synapses in living mice. Time-lapse imaging revealed that recycled AChRs were incorporated into the synapse within hours of initial labeling, and their numbers increased with time. At fully functional synapses, AChR recycling was robust and comparable in magnitude with the insertion of newly synthesized receptors, whereas chronic synaptic activity blockade nearly abolished receptor recycling. Finally, using the same sequential labeling method, we found that acetylcholinesterase, another synaptic component, does not recycle. These results identify an activity-dependent AChR-recycling mechanism that enables the regulation of receptor density, which could lead to rapid alterations in synaptic efficacy.
  • Publication
    Giving the Underdog a Leg Up: A Counternarrative of Nonviolent Resistance Improves Sustained Third-Party Support of a Disempowered Group
    (2017-09-01) Bruneau, Emile; Lane, Daniel; Saleem, Muniba
    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.
  • Publication
    In-Group/Out-Group Distinctions—Neuroscience Findings and Upshot
    (2012-07-01) Bruneau, Emile
    This White Volume assesses U.S. long term national security challenges, employing a global perspective that accounts for the changing political, economic, social, and psychological profiles of populations, and the rapid changes they experience in a globally connected information environment. It addresses many of the key national security challenges identified by LTG Flynn in the Preface. The collection of essays explores future population-centric national security challenges through the lens of the latest research from the social, neurobiological, and complexity sciences. The papers emphasize "enduring" long term theses that are focused on the interactions of populations and their environments. They are not U.S.-centric, but multi-perspective and examine underlying long term phenomena. The target audiences are planners, operators, and policy makers. With them in mind, the articles are intentionally kept short and written to stand alone. All the contributors have done their best to make their articles easily accessible.
  • Publication
    The Dynamics of the Rapsyn Scaffolding Protein at Individual Acetylcholine Receptor Clusters
    (2007-03-01) Bruneau, Emile; Akaaboune, Mohammed
    Rapsyn, a cytoplasmic receptor-associated protein, is required for the clustering of acetylcholine receptors (AChRs). Although AChR dynamics have been extensively studied, little is known about the dynamics of rapsyn. Here, we used a rapsyn-green fluorescent protein (GFP) fusion protein and quantitative fluorescent imaging to study the dynamics of rapsyn in transfected C2C12 myotubes. First, we found that rapsyn-GFP expression at clusters did not alter AChR aggregation, function, or turnover. Quantification of rapsyn immunofluorescence indicated that the expression of rapsyn-GFP proteins at clusters does not increase the overall rapsyn density compared with untransfected myotube clusters. Using time lapse imaging and fluorescence recovery after photobleaching, we demonstrated that the recovery of rapsyn-GFP fluorescence at clusters was very fast, with a halftime of about ∼1.5 h (∼3 times faster than AChRs). Inhibition of protein kinase C significantly altered receptor insertion, but it had no effect on rapsyn insertion. When cells were treated with the broad spectrum kinase inhibitor staurosporine, receptor insertion was decreased even further. However, inhibition of protein kinase A had no effect on insertion of either rapsyn or receptors. Finally, when cells were treated with neural agrin, rapsyn and AChRs were both directed away from preexisting clusters and accumulated together in new small clusters. These results demonstrate the remarkable dynamism of rapsyn, which may underlie the stability and maintenance of the postsynaptic scaffold and suggest that the insertion of different postsynaptic proteins may be operating independently.
  • Publication
    Minding the Gap: Narrative Descriptions about Mental States Attenuate Parochial Empathy
    (2015-10-01) Bruneau, Emile; Cikara, Mina; Saxe, Rebecca
    In three experiments, we examine parochial empathy (feeling more empathy for in-group than out-group members) across novel group boundaries, and test whether we can mitigate parochial empathy with brief narrative descriptions. In the absence of individuating information, participants consistently report more empathy for members of their own assigned group than a competitive out-group. However, individualized descriptions of in-group and out-group targets significantly reduce parochial empathy by interfering with encoding of targets’ group membership. Finally, the descriptions that most effectively decrease parochial empathy are those that describe targets’ mental states. These results support the role of individuating information in ameliorating parochial empathy, suggest a mechanism for their action, and show that descriptions emphasizing targets’ mental states are particularly effective.