Prosocial aggression tracks genetic relatedness distinctly from emotional closeness

Altruistic behavior is understood to largely stem from adaptations for kin altruism, contingent on degree of relatedness, and/or reciprocal altruism, contingent on degree of benefits conferred in exchange for help. Because kin qualify for both kin and reciprocal altruism, they should receive greater support than friends, as has been demonstrated in prior research. Here, we tested this prediction with regard to willingness to punish on another's behalf, comparing inclinations to aggress against transgressors when the victim was framed as an acquaintance, close friend, cousin, sibling, or oneself. Participants endorsed comparably greater direct aggression on behalf of the self, kin, or friends relative to acquaintances, despite reporting substantially greater emotional closeness to friends, consistent with what has been termed a kinship premium. Kin engendered greater aid than is explicable by affiliative emotion. Participants also reported less anger-yet trends toward greater disgust-when victims were acquaintances relative to all other conditions, replicating prior work distinguishing the social functions of anger and disgust. These results are discussed as they inform both the kinship premium hypothesis and sociofunctional accounts of moral emotion. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Hardwiring tissue-specific AAV transduction in mice through engineered receptor expression

The development of transgenic mouse models that express genes of interest in specific cell types has transformed our understanding of basic biology and disease. However, generating these models is time- and resource-intensive. Here we describe a model system, SELective Expression and Controlled Transduction In Vivo (SELECTIV), that enables efficient and specific expression of transgenes by coupling adeno-associated virus (AAV) vectors with Cre-inducible overexpression of the multi-serotype AAV receptor, AAVR. We demonstrate that transgenic AAVR overexpression greatly increases the efficiency of transduction of many diverse cell types, including muscle stem cells, which are normally refractory to AAV transduction. Superior specificity is achieved by combining Cre-mediated AAVR overexpression with whole-body knockout of endogenous Aavr, which is demonstrated in heart cardiomyocytes, liver hepatocytes and cholinergic neurons. The enhanced efficacy and exquisite specificity of SELECTIV has broad utility in development of new mouse model systems and expands the use of AAV for gene delivery in vivo.

Greater traditionalism predicts COVID-19 precautionary behaviors across 27 societies

People vary both in their embrace of their society's traditions, and in their perception of hazards as salient and necessitating a response. Over evolutionary time, traditions have offered avenues for addressing hazards, plausibly resulting in linkages between orientations toward tradition and orientations toward danger. Emerging research documents connections between traditionalism and threat responsivity, including pathogen-avoidance motivations. Additionally, because hazard-mitigating behaviors can conflict with competing priorities, associations between traditionalism and pathogen avoidance may hinge on contextually contingent tradeoffs. The COVID-19 pandemic provides a real-world test of the posited relationship between traditionalism and hazard avoidance. Across 27 societies (N = 7844), we find that, in a majority of countries, individuals' endorsement of tradition positively correlates with their adherence to costly COVID-19-avoidance behaviors; accounting for some of the conflicts that arise between public health precautions and other objectives further strengthens this evidence that traditionalism is associated with greater attention to hazards.

Coalitionality shapes moral elevation: evidence from the U.S. Black Lives Matter protest and counter-protest movements

Witnessing altruistic behaviour can elicit moral elevation, an emotion that motivates prosocial cooperation. This emotion is evoked more strongly when the observer anticipates that other people will be reciprocally cooperative. Coalitionality should therefore moderate feelings of elevation, as whether the observer shares the coalitional affiliation of those observed should influence the observer's assessment of the likelihood that the latter will cooperate with the observer. We examined this thesis in studies contemporaneous with the 2020 Black Lives Matter (BLM) protests. Although BLM protests were predominantly peaceful, they were depicted by conservative media as destructive and antisocial. In two large-scale, pre-registered online studies (total N = 2172), political orientation strongly moderated feelings of state elevation elicited by a video of a peaceful BLM protest (Studies 1 and 2) or a peaceful Back the Blue (BtB) counter-protest (Study 2). Political conservatism predicted less elevation following the BLM video and more elevation following the BtB video. Elevation elicited by the BLM video correlated with preferences to defund police, whereas elevation elicited by the BtB video correlated with preferences to increase police funding. These findings extend prior work on elevation into the area of prosocial cooperation in the context of coalitional conflict.

Moral parochialism and causal appraisal of transgressive harm in Seoul and Los Angeles

The evolutionary fitness payoffs of moral condemnation are greatest within an individual’s immediate social milieu. Accordingly, insofar as human moral intuitions have been shaped by adaptive design, we can expect transgressive harms to be perceived as more wrong when transpiring in the here and now than when occurring at a distance, or with the approval of local authority figures. This moral parochialism hypothesis has been supported by research conducted in diverse societies, but has yet to be tested in an East Asian society, despite prior research indicating that East Asians appraise transgressive acts as being caused by situational and contextual factors to a greater extent than do Westerners, who tend to emphasize dispositional factors (i.e., the transgressor’s personal nature). Here, in a quasi-experiment using field samples recruited in Seoul and Los Angeles, we tested (i) the moral parochialism hypothesis regarding the perceived wrongness of transgressions, as well as (ii) the extent to which these wrongness judgments might be influenced by cross-cultural differences in causal appraisals. Despite notably large differences across the two societies in situational versus dispositional appraisals of the causes of the transgressions, replicating previous findings elsewhere, in both societies we found that transgressions were deemed less wrong when occurring at spatial or temporal remove or with the consent of authorities. These findings add to the understanding of morality as universally focused on local affairs, notwithstanding cultural variation in perceptions of the situational versus dispositional causes of (im)moral acts.

Posterior medial frontal cortex regulates sympathy: A TMS study

Harm to some elicits greater sympathy than harm to others. Here, we examine the role of posterior medial frontal cortex (PMFC) in regulating sympathy, and explore the potential role of PMFC in the related phenomena of mentalizing and representing others as connected with oneself. We down-regulated either PMFC or a control region (middle temporal visual area), then assessed feelings of sympathy for and self-other overlap with two characters described as having suffered physical harm, and who were framed as adversarial or affiliative, respectively. We also measured mentalizing performance with regard to inferring the cognitive and affective states of the adversarial character. As hypothesized, down-regulating PMFC increased sympathy for both characters. Whereas we had predicted that down-regulating PMFC would decrease mentalizing ability given the postulated role of PMFC in the mentalizing network, participants in the PMFC down-regulation condition evinced greater second-order cognitive inference ability relative to controls. We observed no effect of the TMS manipulation on self-other overlap, although sympathy and self-other overlap were positively correlated. These findings are discussed as they may inform understanding of the functional role(s) of PMFC in regulating responses broadly linked with empathy.

Increased tissue stiffness triggers contractile dysfunction and telomere shortening in dystrophic cardiomyocytes

Duchenne muscular dystrophy (DMD) is a rare X-linked recessive disease that is associated with severe progressive muscle degeneration culminating in death due to cardiorespiratory failure. We previously observed an unexpected proliferation-independent telomere shortening in cardiomyocytes of a DMD mouse model. Here, we provide mechanistic insights using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Using traction force microscopy, we show that DMD hiPSC-CMs exhibit deficits in force generation on fibrotic-like bioengineered hydrogels, aberrant calcium handling, and increased reactive oxygen species levels. Furthermore, we observed a progressive post-mitotic telomere shortening in DMD hiPSC-CMs coincident with downregulation of shelterin complex, telomere capping proteins, and activation of the p53 DNA damage response. This telomere shortening is blocked by blebbistatin, which inhibits contraction in DMD cardiomyocytes. Our studies underscore the role of fibrotic stiffening in the etiology of DMD cardiomyopathy. In addition, our data indicate that telomere shortening is progressive, contraction dependent, and mechanosensitive, and suggest points of therapeutic intervention.

The skin crawls, the stomach turns: ectoparasites and pathogens elicit distinct defensive responses in humans

Disgust has long been viewed as a primary motivator of defensive responses to threats posed by both microscopic pathogens and macroscopic ectoparasites. Although disgust can defend effectively against pathogens encountered through ingestion or incidental contact, it offers limited protection against ectoparasites, which actively pursue a host and attach to its surface. Humans might, therefore, possess a distinct ectoparasite defence system-including cutaneous sensory mechanisms and grooming behaviours-functionally suited to guard the body's surface. In two US studies and one in China, participants (N = 1079) viewed a range of ectoparasite- and pathogen-relevant video stimuli and reported their feelings, physiological sensations, and behavioural motivations. Participants reported more surface-guarding responses towards ectoparasite stimuli than towards pathogen stimuli, and more ingestion/contamination-reduction responses towards pathogen stimuli than towards ectoparasite stimuli. Like other species, humans appear to possess evolved psychobehavioural ectoparasite defence mechanisms that are distinct from pathogen defence mechanisms.

Of pathogens and party lines: Social conservatism positively associates with COVID-19 precautions among U.S. Democrats but not Republicans

Social liberals tend to be less pathogen-avoidant than social conservatives, a pattern consistent with a model wherein ideological differences stem from differences in threat reactivity. Here we investigate if and how individual responses to a shared threat reflect those patterns of ideological difference. In seeming contradiction to the general association between social conservatism and pathogen avoidance, the more socially conservative political party in the United States has more consistently downplayed the dangers of COVID-19 during the ongoing pandemic. This puzzle offers an opportunity to examine the contributions of multiple factors to disease avoidance. We investigated the relationship between social conservatism and COVID-19 precautionary behavior in light of the partisan landscape of the United States. We explored whether consumption of, and attitudes toward, different sources of information, as well as differential evaluation of various threats caused by the pandemic-such as direct health costs versus indirect harms to the economy and individual liberties-shape partisan differences in responses to the pandemic in ways that overwhelm the contributions of social conservatism. In two pre-registered studies, socially conservative attitudes correlate with self-reported COVID-19 prophylactic behaviors, but only among Democrats. Reflecting larger societal divisions, among Republicans and Independents, the absence of a positive relationship between social conservatism and COVID-19 precautions appears driven by lower trust in scientists, lower trust in liberal and moderate sources, lesser consumption of liberal news media, and greater economic conservatism.

Of pathogens and party lines: Social conservatism positively associates with COVID-19 precautions among U.S. Democrats but not Republicans

Social liberals tend to be less pathogen-avoidant than social conservatives, a pattern consistent with a model wherein ideological differences stem from differences in threat reactivity. Here we investigate if and how individual responses to a shared threat reflect those patterns of ideological difference. In seeming contradiction to the general association between social conservatism and pathogen avoidance, the more socially conservative political party in the United States has more consistently downplayed the dangers of COVID-19 during the ongoing pandemic. This puzzle offers an opportunity to examine the contributions of multiple factors to disease avoidance. We investigated the relationship between social conservatism and COVID-19 precautionary behavior in light of the partisan landscape of the United States. We explored whether consumption of, and attitudes toward, different sources of information, as well as differential evaluation of various threats caused by the pandemic-such as direct health costs versus indirect harms to the economy and individual liberties-shape partisan differences in responses to the pandemic in ways that overwhelm the contributions of social conservatism. In two pre-registered studies, socially conservative attitudes correlate with self-reported COVID-19 prophylactic behaviors, but only among Democrats. Reflecting larger societal divisions, among Republicans and Independents, the absence of a positive relationship between social conservatism and COVID-19 precautions appears driven by lower trust in scientists, lower trust in liberal and moderate sources, lesser consumption of liberal news media, and greater economic conservatism.

Posterior medial frontal cortex and threat-enhanced religious belief: a replication and extension

Research indicates that the posterior medial frontal cortex (pMFC) functions as a 'neural alarm' complex broadly involved in registering threats and helping to muster relevant responses. Holbrook and colleagues investigated whether pMFC similarly mediates ideological threat responses, finding that downregulating pMFC via transcranial magnetic stimulation (TMS) caused (i) less avowed religious belief despite being reminded of death and (ii) less group bias despite encountering a sharp critique of the national in-group. While suggestive, these findings were limited by the absence of a non-threat comparison condition and reliance on sham rather than control TMS. Here, in a pre-registered replication and extension, we downregulated pMFC or a control region (MT/V5) and then primed participants with either a reminder of death or a threat-neutral topic. As mentioned previously, participants reminded of death reported less religious belief when pMFC was downregulated. No such effect of pMFC downregulation was observed in the neutral condition, consistent with construing pMFC as monitoring for salient threats (e.g. death) and helping to recruit ideological responses (e.g. enhanced religious belief). However, no effect of downregulating pMFC on group bias was observed, possibly due to reliance on a collegiate in-group framing rather than a national framing as in the prior study.

An In Vitro Model for Identifying Cardiac Side Effects of Anesthetics

The understanding of anesthetic side effects on the heart has been hindered by the lack of sophisticated clinical models. Using micropatterned human-induced pluripotent stem cell-derived cardiomyocytes, we obtained cardiac muscle depressant profiles for propofol, etomidate, and our newly identified anesthetic compound KSEB01-S2. Propofol was the strongest depressant among the 3 compounds tested, exhibiting the largest decrease in contraction velocity, depression rate, and beating frequency. Interestingly, KSEB01-S2 behaved similarly to etomidate, suggesting a better cardiac safety profile. Our results provide a proof-of-concept for using human-induced pluripotent stem cell-derived cardiomyocytes as an in vitro platform for future drug design.

Factors Predicting Willingness to Share COVID-19 Misinformation

We conducted a preregistered exploratory survey to assess whether patterns of individual differences in political orientation, social dominance orientation (SDO), traditionalism, conspiracy ideation, or attitudes about science predict willingness to share different kinds of misinformation regarding the COVID-19 pandemic online. Analyses revealed two orthogonal models of individual differences predicting the willingness to share misinformation over social media platforms. Both models suggest a sizable role of different aspects of political belief, particularly SDO, in predicting tendencies to share different kinds of misinformation, predominantly conspiracy theories. Although exploratory, results from this study can contribute to the formulation of a socio-cognitive profile of individuals who act as vectors for the spread of scientific misinformation online, and can be useful for computationally modeling misinformation diffusion.

Gruesomeness conveys formidability: Perpetrators of gratuitously grisly acts are conceptualized as larger, stronger, and more likely to win

While associated with extreme terrorist organizations in modern times, extensive accounts of grisly acts of violence exist in the archeological, historical, and ethnographic records. Though reasons for this dramatic form of violence are multifaceted and diverse, one possibility is that violence beyond what is required to win a conflict is a method by which violent actors communicate to others that they are formidable opponents. The formidability representation hypothesis predicts that formidability is cognitively represented using the dimensions of envisioned bodily size and strength. We tested the informational ramifications of gruesome acts using two vignette studies depicting individuals who either did or did not grievously damage the corpse of a deceased foe. Participants rated the individual's height, bodily size, and strength, as well as his aggressiveness, motivation, and the capacity to vanquish opponents in future conflicts. Results indicate that, as predicted, committing gruesome acts of violence enhances perceptions of formidability as measured both by envisioned bodily size and strength and expectations regarding the outcomes of agonistic conflicts. Moreover, the gruesome actor was perceived as more aggressive and more motivated to overcome his enemies, and this mediated the increase in conceptualized size and strength. These results both provide further evidence for the formidability representation hypothesis and support the thesis that overtly grisly violence is tactically employed, in part, because it conveys information about the perpetrator's formidability.

Morality is relative: Anger, disgust, and aggression as contingent responses to sibling versus acquaintance harm

Angry reactions to moral violations should be heightened when wrongs befall oneself in comparison with when wrongs befall acquaintances, as prior research by Molho, Tybur, Güler, Balliet, and Hofmann (2017) demonstrates, because aggressive confrontation is inherently risky and therefore only incentivized by natural selection to curtail significant fitness costs. Here, in 3 preregistered studies, we extend this sociofunctional perspective to cases of wrongs inflicted on siblings. We observed equivalently heightened anger in response to transgressions against either oneself or one's sibling relative to transgressions against acquaintances across studies, whereas transgressions against acquaintances evoked greater disgust and/or fear (both associated with social avoidance) in 2 of the 3 studies. Studies 2 and 3, which incorporated measures of tendencies to confront the transgressor, confirmed that the elevated anger elicited by self or sibling harm partially mediated heightened inclinations toward direct aggression. Finally, in Study 3 we compared tendencies to experience anger and to directly aggress on behalf of siblings and close friends. Despite reporting greater affiliative closeness for friends than for siblings, harm to friends failed to evoke heightened anger relative to acquaintance harm, and participants were inclined to directly aggress against those who had harmed their sibling to a significantly greater extent than when the harm befell their friend. These overall results broadly replicate Molho et al.'s (2017) findings and theoretically extend the sociofunctionalist account of moral emotions to kinship. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Elevation, an emotion for prosocial contagion, is experienced more strongly by those with greater expectations of the cooperativeness of others

A unique emotion, elevation, is thought to underlie prosocial contagion, a process whereby witnessing a prosocial act leads to acting prosocially. Individuals differ in their propensity to experience elevation, and thus their proneness to prosocial contagion, but little is known about the causes of such variation. We introduce an adaptationist model wherein elevation marks immediate circumstances in which generalized prosociality is advantageous, with this evaluation of circumstances hinging in part on prior expectations of others' prosociality. In 15 studies, we add to evidence that elevation can reliably be elicited and mediates prosocial contagion. Importantly, we confirm a novel prediction-generated by our adaptationist account-that an idealistic attitude, which indexes others' expected degree of prosociality, moderates the relationship between exposure to prosocial cues and experiencing elevation. We discuss how our findings inform both basic theorizing in the affective sciences and translational efforts to engineer a more harmonious world, and we offer future research directions to further test and extend our model.

Religiosity Predicts Evidentiary Standards

Research shows that religious and nonreligious individuals have different standards of evidence for religious and scientific claims. Here, in a preregistered replication and extension of McPhetres and Zuckerman, participants read about an effect attributed to either a scientific or religious cause, then assessed how much evidence, in the form of successful replications, would be needed to confirm or to reject the causal claim. As previously observed, religious individuals exhibited a bias for believing religious claims relative to scientific claims, while nonreligious individuals were consistent in their standards of evidence across domains. In a novel extension examining standards of evidence with respect to failures of replication, we found that religious individuals were consistent across domains, whereas nonreligious individuals indicated a lower threshold for rejecting religious claims relative to scientific claims. These findings indicate asymmetries in the evaluation of claims based on the presence versus absence of supportive evidence.

Does observing reciprocity or exploitation affect elevation, a mechanism driving prosociality?

Fitness is enhanced by determining when to behave prosocially. Elevation, an uplifting emotion elicited by witnessing exemplary prosociality, upregulates prosociality in the presence of prosocial others, as such contexts render prosociality profitable and/or antisociality costly. Prior research examines responses to a single highly prosocial individual. However, the profitability of enhancing prosociality hinges not only on potential interactions with a single actor, but also on the actions of others. Accordingly, information regarding how others respond to the prosocial exemplar may influence elevation elicitation and corresponding changes in prosocial motivation. If others reciprocate the exemplar's prosociality, or pay prosociality forward, this expands opportunities for the observer to profit by increasing prosociality, and thus could enhance elevation elicitation. Conversely, if others exploit the exemplar, this may diminish the profitability of prosociality, as the observer who acts prosocially may similarly be exploited and/or the resources with which the exemplar could reciprocate will be depleted. Conducting three online studies of Americans in which information regarding the responses of others to a prosocial exemplar was manipulated, we find that, against predictions, prosocial responses by the beneficiaries of prosociality generally do not enhance elevation among observers, whereas, consonant with predictions, antisocial responses markedly diminish elevation among observers.

Electoral fortunes reverse, mindsets do not

Conservatives and liberals have previously been shown to differ in the propensity to view socially-transmitted information about hazards as more plausible than that concerning benefits. Given differences between conservatives and liberals in threat sensitivity and dangerous-world beliefs, correlations between political orientation and negatively-biased credulity may thus reflect endogenous mindsets. Alternatively, such results may owe to the political hierarchy at the time of previous research, as the tendency to see dark forces at work is thought to be greater among those who are out of political power. Adjudicating between these accounts can inform how societies respond to the challenge of alarmist disinformation campaigns. We exploit the consequences of the 2016 U.S. elections to test these competing explanations of differences in negatively-biased credulity and conspiracism as a function of political orientation. Two studies of Americans reveal continued positive associations between conservatism, negatively-biased credulity, and conspiracism despite changes to the power structure in conservatives’ favor.

Cues of Violent Intergroup Conflict Diminish Perceptions of Robotic Personhood

Convergent lines of evidence indicate that anthropomorphic robots are represented using neurocognitive mechanisms typically employed in social reasoning about other people. Relatedly, a growing literature documents that contexts of threat can exacerbate coalitional biases in social perceptions. Integrating these research programs, the present studies test whether cues of violent intergroup conflict modulate perceptions of the intelligence, emotional experience, or overall personhood of robots. In Studies 1 and 2, participants evaluated a large, bipedal all-terrain robot; in Study 3, participants evaluated a small, social robot with humanlike facial and vocal characteristics. Across all studies, cues of violent conflict caused significant decreases in perceived robotic personhood, and these shifts were mediated by parallel reductions in emotional connection with the robot (with no significant effects of threat on attributions of intelligence/skill). In addition, in Study 2, participants in the conflict condition estimated the large bipedal robot to be less effective in military combat, and this difference was mediated by the reduction in perceived robotic personhood. These results are discussed as they motivate future investigation into the links among threat, coalitional bias and human–robot interaction.

Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses

Decades of behavioral science research have documented functional shifts in attitudes and ideological adherence in response to various challenges, but little work to date has illuminated the neural mechanisms underlying these dynamics. This paper describes how continuous theta burst transcranial magnetic stimulation may be employed to experimentally assess the causal contribution of cortical regions to threat-related ideological shifts. In the example protocol provided here, participants are exposed to a threat prime-an explicit reminder of their own inevitable death and bodily decomposition-following a downregulation of the posterior medial frontal cortex (pMFC) or a sham stimulation. Next, disguised within a series of distracter tasks, participants' relative degree of ideological adherence is assessed-in the present example, with regard to coalitional prejudice and religious belief. Participants for whom the pMFC has been downregulated exhibit less coalitionally biased responses to an immigrant critical of the participants' national in-group, and less conviction in positive afterlife beliefs (i.e., God, angels, and heaven), despite having recently been reminded of death. These results complement prior findings that continuous theta burst stimulation of the pMFC influences social conformity and sharing and illustrate the feasibility of investigating the neural basis of high-level social cognitive shifts using transcranial magnetic stimulation.

Battle of Wits

Political conservatism and threat salience have been consistently associated with intergroup bias. However, prior research has not examined potential effects of conservatism and/or threat on the attribution of relative in-group/out-group intelligence. In a cross-cultural study conducted in Spain and the United Kingdom, priming violent conflict with ISIS led participants to view an in-group ally as relatively more intelligent than an out-group adversary, in an effect mediated by feelings of anger (but not fear or general arousal). Conservatism similarly predicted biased perception of the ally’s relative intellect, a tendency that was driven by militaristic (not social/fiscal) political attitudes but was not explained by associated increases in state anger following conflict cues. This overall pattern indicates that conflict cues and militaristic political orientation heighten assessments of relative intergroup intellect during warfare via distinct affective and attitudinal pathways.

Disgust as a mechanism for decision making under risk: Illuminating sex differences and individual risk-taking correlates of disgust propensity

The emotion disgust motivates costly behavioral strategies that mitigate against potentially larger costs associated with pathogens, sexual behavior, and moral transgressions. Because disgust thereby regulates exposure to harm, it is by definition a mechanism for calibrating decision making under risk. Understanding this illuminates two features of the demographic distribution of this emotion. First, this approach predicts and explains sex differences in disgust. Greater female disgust propensity is often reported and discussed in the literature, but, to date, conclusions have been based on informal comparisons across a small number of studies, while existing functionalist explanations are at best incomplete. We report the results of an extensive meta-analysis documenting this sex difference, arguing that key features of this pattern are best explained as one manifestation of a broad principle of the evolutionary biology of risk-taking: for a given potential benefit, males in an effectively polygynous mating system accept the risk of harm more willingly than do females. Second, viewing disgust as a mechanism for decision making under risk likewise predicts that individual differences in disgust propensity should correlate with individual differences in various forms of risky behavior, because situational and dispositional factors that influence valuation of opportunity and hazard are often correlated across multiple decision contexts. In two large-sample online studies, we find consistent associations between disgust and risk avoidance. We conclude that disgust and related emotions can be usefully examined through the theoretical lens of decision making under risk in light of human evolution. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Political Orientation Predicts Credulity Regarding Putative Hazards

To benefit from information provided by other people, people must be somewhat credulous. However, credulity entails risks. The optimal level of credulity depends on the relative costs of believing misinformation and failing to attend to accurate information. When information concerns hazards, erroneous incredulity is often more costly than erroneous credulity, given that disregarding accurate warnings is more harmful than adopting unnecessary precautions. Because no equivalent asymmetry exists for information concerning benefits, people should generally be more credulous of hazard information than of benefit information. This adaptive negatively biased credulity is linked to negativity bias in general and is more prominent among people who believe the world to be more dangerous. Because both threat sensitivity and beliefs about the dangerousness of the world differ between conservatives and liberals, we predicted that conservatism would positively correlate with negatively biased credulity. Two online studies of Americans supported this prediction, potentially illuminating how politicians' alarmist claims affect different portions of the electorate.

Gulliver’s Politics

Political conservatives have been widely documented to regard out-group members as hostile, perceive individuals of ambiguous intent as malevolent, and favor aggressive solutions to intergroup conflict. A growing literature indicates that potential violent adversaries are represented using the dimensions of envisioned physical size/strength to summarize opponents’ fighting capacities relative to the self or in-group. Integrating these programs, we hypothesized that, compared to liberals, conservatives would envision an ambiguous out-group target as more likely to pose a threat, yet as vanquishable through force, and thus as less formidable. Participants from the United States (Study 1) and Spain (Study 2) assessed Syrian refugees, a group that the public widely suspects includes terrorists. As predicted, in both societies, conservatives envisioned refugees as more likely to be terrorists and as less physically formidable. As hypothesized, this “Gulliver effect” was mediated by confidence in each society’s capacity to thwart terrorism via aggressive military or police measures.

Moral parochialism and contextual contingency across seven societies

Human moral judgement may have evolved to maximize the individual's welfare given parochial culturally constructed moral systems. If so, then moral condemnation should be more severe when transgressions are recent and local, and should be sensitive to the pronouncements of authority figures (who are often arbiters of moral norms), as the fitness pay-offs of moral disapproval will primarily derive from the ramifications of condemning actions that occur within the immediate social arena. Correspondingly, moral transgressions should be viewed as less objectionable if they occur in other places or times, or if local authorities deem them acceptable. These predictions contrast markedly with those derived from prevailing non-evolutionary perspectives on moral judgement. Both classes of theories predict purportedly species-typical patterns, yet to our knowledge, no study to date has investigated moral judgement across a diverse set of societies, including a range of small-scale communities that differ substantially from large highly urbanized nations. We tested these predictions in five small-scale societies and two large-scale societies, finding substantial evidence of moral parochialism and contextual contingency in adults' moral judgements. Results reveal an overarching pattern in which moral condemnation reflects a concern with immediate local considerations, a pattern consistent with a variety of evolutionary accounts of moral judgement.

Dressed to kill? Visible markers of coalitional affiliation enhance conceptualized formidability

Displaying markers of coalitional affiliation is a common feature of contemporary life. In situations in which interaction with members of rival coalitions is likely, signaling coalitional affiliation may simultaneously constitute an implicit challenge to opponents and an objective commitment device, binding signalers to their coalitions. Individuals who invite conflict, and who cannot readily back out of conflict, constitute a greater threat than those who avoid conflict and preserve the option of feigning neutrality. As a consequence, the former should be viewed as more formidable than the latter. Recent research indicates that relative formidability is summarized using the envisioned physical size and strength of a potential antagonist. Thus, individuals who display markers of coalitional affiliation should be conceptualized as more physically imposing than those who do not. We tested this prediction in two experiments. In Study 1, conducted with U.S. university students, participants inspected images of sports fans' faces. In Study 2, conducted with U.S. Mechanical Turk workers, participants read vignettes depicting political partisans. In both studies, participants estimated the physical formidability of the target individuals and reported their own ability to defend themselves; in Study 2, participants estimated the target's aggressiveness. Consonant with predictions, targets depicted as signaling coalitional affiliation in situations of potential conflict were envisioned to be more physically formidable and more aggressive than were those not depicted as signaling thusly. Underscoring that the calculations at issue concern the possibility of violent conflict, participants' estimates of the protagonist's features were inversely correlated with their ability to defend themselves.

With God on our side: Religious primes reduce the envisioned physical formidability of a menacing adversary

The imagined support of benevolent supernatural agents attenuates anxiety and risk perception. Here, we extend these findings to judgments of the threat posed by a potentially violent adversary. Conceptual representations of bodily size and strength summarize factors that determine the relative threat posed by foes. The proximity of allies moderates the envisioned physical formidability of adversaries, suggesting that cues of access to supernatural allies will reduce the envisioned physical formidability of a threatening target. Across two studies, subtle cues of both supernatural and earthly social support reduced the envisioned physical formidability of a violent criminal. These manipulations had no effect on the perceived likelihood of encountering non-conflictual physical danger, raising the possibility that imagined supernatural support leads participants to view themselves not as shielded from encountering perilous situations, but as protected should perils arise.

Moral asymmetries in judgments of agency withstand ludicrous causal deviance

Americans have been shown to attribute greater intentionality to immoral than to amoral actions in cases of causal deviance, that is, cases where a goal is satisfied in a way that deviates from initially planned means (e.g., a gunman wants to hit a target and his hand slips, but the bullet ricochets off a rock into the target). However, past research has yet to assess whether this asymmetry persists in cases of extreme causal deviance. Here, we manipulated the level of mild to extreme causal deviance of an immoral versus amoral act. The asymmetry in attributions of intentionality was observed at all but the most extreme level of causal deviance, and, as we hypothesized, was mediated by attributions of blame/credit and judgments of action performance. These findings are discussed as they support a multiple-concepts interpretation of the asymmetry, wherein blame renders a naïve concept of intentional action (the outcome matches the intention) more salient than a composite concept (the outcome matches the intention and was brought about by planned means), and in terms of their implications for cross-cultural research on judgments of agency.

Neuromodulation of group prejudice and religious belief

People cleave to ideological convictions with greater intensity in the aftermath of threat. The posterior medial frontal cortex (pMFC) plays a key role in both detecting discrepancies between desired and current conditions and adjusting subsequent behavior to resolve such conflicts. Building on prior literature examining the role of the pMFC in shifts in relatively low-level decision processes, we demonstrate that the pMFC mediates adjustments in adherence to political and religious ideologies. We presented participants with a reminder of death and a critique of their in-group ostensibly written by a member of an out-group, then experimentally decreased both avowed belief in God and out-group derogation by downregulating pMFC activity via transcranial magnetic stimulation. The results provide the first evidence that group prejudice and religious belief are susceptible to targeted neuromodulation, and point to a shared cognitive mechanism underlying concrete and abstract decision processes. We discuss the implications of these findings for further research characterizing the cognitive and affective mechanisms at play.

Reversibility of Defective Hematopoiesis Caused by Telomere Shortening in Telomerase Knockout Mice

Telomere shortening is common in bone marrow failure syndromes such as dyskeratosis congenita (DC), aplastic anemia (AA) and myelodysplastic syndromes (MDS). However, improved knowledge of the lineage-specific consequences of telomere erosion and restoration of telomere length in hematopoietic progenitors is required to advance therapeutic approaches. We have employed a reversible murine model of telomerase deficiency to compare the dependence of erythroid and myeloid lineage differentiation on telomerase activity. Fifth generation Tert-/- (G5 Tert-/-) mice with shortened telomeres have significant anemia, decreased erythroblasts and reduced hematopoietic stem cell (HSC) populations associated with neutrophilia and increased myelopoiesis. Intracellular multiparameter analysis by mass cytometry showed significantly reduced cell proliferation and increased sensitivity to activation of DNA damage checkpoints in erythroid progenitors and in erythroid-biased CD150hi HSC, but not in myeloid progenitors. Strikingly, Cre-inducible reactivation of telomerase activity restored hematopoietic stem and progenitor cell (HSPC) proliferation, normalized the DNA damage response, and improved red cell production and hemoglobin levels. These data establish a direct link between the loss of TERT activity, telomere shortening and defective erythropoiesis and suggest that novel strategies to restore telomerase function may have an important role in the treatment of the resulting anemia.

Marching into battle: synchronized walking diminishes the conceptualized formidability of an antagonist in men

Paralleling behaviours in other species, synchronized movement is central to institutionalized collective human activities thought to enhance cooperation, and experiments demonstrate that synchrony has this effect. The influence of synchrony on cooperation may derive from an evolutionary history wherein such actions served to signal coalitional strength to both participants and observers-including adversaries. If so, then synchronous movement should diminish individuals' estimations of a foe's formidability. Envisioned physical size and strength constitute the dimensions of a representation that summarizes relative fighting capacity. Experiencing synchrony should therefore lead individuals to conceptualize an antagonist as smaller and weaker. We found that men who walked synchronously with a male confederate indeed envisioned a purported criminal as less physically formidable than did men who engaged in this task without synchronizing.

Direct evaluation of myocardial viability and stem cell engraftment demonstrates salvage of the injured myocardium

RATIONALE

The mechanism of functional restoration by stem cell therapy remains poorly understood. Novel manganese-enhanced MRI and bioluminescence reporter gene imaging were applied to follow myocardial viability and cell engraftment, respectively. Human-placenta-derived amniotic mesenchymal stem cells (AMCs) demonstrate unique immunoregulatory and precardiac properties. In this study, the restorative effects of 3 AMC-derived subpopulations were examined in a murine myocardial injury model: (1) unselected AMCs, (2) ckit(+)AMCs, and (3) AMC-derived induced pluripotent stem cells (MiPSCs).

OBJECTIVE

To determine the differential restorative effects of the AMC-derived subpopulations in the murine myocardial injury model using multimodality imaging.

METHODS AND RESULTS

SCID (severe combined immunodeficiency) mice underwent left anterior descending artery ligation and were divided into 4 treatment arms: (1) normal saline control (n=14), (2) unselected AMCs (n=10), (3) ckit(+)AMCs (n=13), and (4) MiPSCs (n=11). Cardiac MRI assessed myocardial viability and left ventricular function, whereas bioluminescence imaging assessed stem cell engraftment during a 4-week period. Immunohistological labeling and reverse transcriptase polymerase chain reaction of the explanted myocardium were performed. The unselected AMC and ckit(+)AMC-treated mice demonstrated transient left ventricular functional improvement. However, the MiPSCs exhibited a significantly greater increase in left ventricular function compared with all the other groups during the entire 4-week period. Left ventricular functional improvement correlated with increased myocardial viability and sustained stem cell engraftment. The MiPSC-treated animals lacked any evidence of de novo cardiac differentiation.

CONCLUSION

The functional restoration seen in MiPSCs was characterized by increased myocardial viability and sustained engraftment without de novo cardiac differentiation, indicating salvage of the injured myocardium.

Transient delivery of modified mRNA encoding TERT rapidly extends telomeres in human cells

Telomere extension has been proposed as a means to improve cell culture and tissue engineering and to treat disease. However, telomere extension by nonviral, nonintegrating methods remains inefficient. Here we report that delivery of modified mRNA encoding TERT to human fibroblasts and myoblasts increases telomerase activity transiently (24-48 h) and rapidly extends telomeres, after which telomeres resume shortening. Three successive transfections over a 4 d period extended telomeres up to 0.9 kb in a cell type-specific manner in fibroblasts and myoblasts and conferred an additional 28 ± 1.5 and 3.4 ± 0.4 population doublings (PDs), respectively. Proliferative capacity increased in a dose-dependent manner. The second and third transfections had less effect on proliferative capacity than the first, revealing a refractory period. However, the refractory period was transient as a later fourth transfection increased fibroblast proliferative capacity by an additional 15.2 ± 1.1 PDs, similar to the first transfection. Overall, these treatments led to an increase in absolute cell number of more than 10(12)-fold. Notably, unlike immortalized cells, all treated cell populations eventually stopped increasing in number and expressed senescence markers to the same extent as untreated cells. This rapid method of extending telomeres and increasing cell proliferative capacity without risk of insertional mutagenesis should have broad utility in disease modeling, drug screening, and regenerative medicine.

Further challenges to the "Authentic"/"Hubristic" model of pride: conceptual clarifications and new evidence

The Authentic and Hubristic Pride Scales (AHPS) are the methodological core of an influential perspective on pride. The Authentic Pride (AP) scale purportedly measures a distinct facet of pride rooted in attributing success to effort (but not ability), and related to prestige (but not dominance). The Hubristic Pride (HP) scale purportedly measures a complementary facet rooted in attributing success to ability (but not effort), and related to dominance (but not prestige). In the target article, we presented evidence against both profiles. Here, we first examine the counterarguments raised in defense of both the AHPS and the related appraisal-tendency model, then present a new study confirming that AP is elicited by attributions of success to natural ability, and HP is elicited by attributions of success to causes outside the self. It is thus clear that the HP scale measures not pride, but rather evaluations of the self as overclaiming credit or excessively displaying pride.

Bound to lose: physical incapacitation increases the conceptualized size of an antagonist in men

Because decision-making in situations of potential conflict hinges on assessing many features of the self and the foe, this process can be facilitated by summarizing diverse attributes in a single heuristic representation. Physical size and strength are evolutionarily ancient determinants of victory in conflict, and their relevance is reinforced during development. Accordingly, size and muscularity constitute ready dimensions for a summary representation of relative formidability, a perspective paralleled by the notion that social power is represented using envisioned relative size. Physical incapacitation constitutes a significant tactical disadvantage, hence temporary incapacitation should increase the envisioned size and strength of an antagonist. In Study 1, being bound to a chair increased men’s estimates of the size of an angry man and decreased estimates of their own height. Study 2 conceptually replicated these effects: among men for whom standing on a balance board was challenging, the attendant experience of postural instability increased estimates of an angry man’s size and muscularity, with similar patterns occurring at a reduced level among all but those whose equilibrium was apparently unaffected by this task.

Friends shrink foes: the presence of comrades decreases the envisioned physical formidability of an opponent

In situations of potential violent conflict, deciding whether to fight, flee, or try to negotiate entails assessing many attributes contributing to the relative formidability of oneself and one's opponent. Summary representations can usefully facilitate such assessments of multiple factors. Because physical size and strength are both phylogenetically ancient and ontogenetically recurrent contributors to the outcome of violent conflicts, these attributes provide plausible conceptual dimensions that may be used by the mind to summarize the relative formidability of opposing parties. Because the presence of allies is a vital factor in determining victory, we hypothesized that men accompanied by male companions would therefore envision a solitary foe as physically smaller and less muscular than would men who were alone. We document the predicted effect in two studies, one using naturally occurring variation in the presence of male companions and one employing experimental manipulation of this factor.

Conceptual and empirical challenges to the "Authentic" versus "Hubristic" model of pride

An increasingly influential perspective in the study of pride holds that there are two distinct facets characterized by distinct ways of appraising the causes of achievement. "Authentic Pride" has been characterized as attributing success to one's temporary effort, whereas "Hubristic Pride" purportedly attributes success to one's stable, innate ability. In four studies, we present evidence against both predicted attributional profiles, and demonstrate that the Hubristic Pride Scale does not measure feelings of pride at all, but rather measures acknowledgment that one has displayed pride in an excessive manner. In Studies 1a and 1b, perceptions of not genuinely meriting credit for successes significantly mediated Hubristic Pride ratings; in Study 2, Hubristic Pride scores correlated with sensitivity to social evaluations of oneself, and in Study 3, Hubristic Pride scores correlated with perceptions of oneself as undeserving of true credit for success. Across studies, Hubristic Pride scores were repeatedly uncorrelated with causal attributions of success to effort, personal ability, stable traits, or the actions of the self, but positively correlated with appraisals of personal shortcomings along these dimensions as causing failure. In contrast to this self-deprecating appraisal style, Authentic Pride scores predicted attributions of success to effort, ability, stable traits, and the self, but negatively correlated with appraisals of the causes of failures. Although our results are incompatible with the Authentic and Hubristic model of pride as previously formulated and measured, we advocate, on evolutionary grounds, for continued inquiry into the prospective two-facet structure of pride using improved instruments.

Sizing up the threat: the envisioned physical formidability of terrorists tracks their leaders' failures and successes

Victory in modern intergroup conflict derives from complex factors, including weaponry, economic resources, tactical outcomes, and leadership. We hypothesize that the mind summarizes such factors into simple metaphorical representations of physical size and strength, concrete dimensions that have determined the outcome of combat throughout both ontogenetic and phylogenetic experience. This model predicts that in the aftermath of tactical victories (e.g., killing an enemy leader), members of defeated groups will be conceptualized as less physically formidable. Conversely, reminders that groups possess effective leadership should lead their members to be envisioned as more physically formidable. Consonant with these predictions, in both an opportunistic study conducted immediately after Osama bin Laden's death was announced (Study 1) and a follow-up experiment conducted approximately a year later (Study 2), Americans for whom the killing was salient estimated a purported Islamic terrorist to be physically smaller/weaker. In Studies 3 and 4, primes of victorious terrorist leaders led to inflated estimates of terrorists' physical attributes. These findings elucidate how the mind represents contemporary military power, and may help to explain how even largely symbolic victories can influence reasoning about campaigns of coalitional aggression.

Weapons make the man (larger): formidability is represented as size and strength in humans

In order to determine how to act in situations of potential agonistic conflict, individuals must assess multiple features of a prospective foe that contribute to the foe's resource-holding potential, or formidability. Across diverse species, physical size and strength are key determinants of formidability, and the same is often true for humans. However, in many species, formidability is also influenced by other factors, such as sex, coalitional size, and, in humans, access to weaponry. Decision-making involving assessments of multiple features is enhanced by the use of a single summary variable that encapsulates the contributions of these features. Given both a) the phylogenetic antiquity of the importance of size and strength as determinants of formidability, and b) redundant experiences during development that underscore the contributions of size and strength to formidability, we hypothesize that size and strength constitute the conceptual dimensions of a representation used to summarize multiple diverse determinants of a prospective foe's formidability. Here, we test this hypothesis in humans by examining the effects of a potential foe's access to weaponry on estimations of that individual's size and strength. We demonstrate that knowing that an individual possesses a gun or a large kitchen knife leads observers to conceptualize him as taller, and generally larger and more muscular, than individuals who possess only tools or similarly mundane objects. We also document that such patterns are not explicable in terms of any actual correlation between gun ownership and physical size, nor can they be explained in terms of cultural schemas or other background knowledge linking particular objects to individuals of particular size and strength. These findings pave the way for a fuller understanding of the evolution of the cognitive systems whereby humans – and likely many other social vertebrates – navigate social hierarchies.