Chimpanzee and hunter-gatherer intergroup aggression differ in important ways, including humans having the ability to form peaceful relationships and alliances among groups. This paper nevertheless evaluates the hypothesis that intergroup aggression evolved according to the same functional principles in the two species—selection favoring a tendency to kill members of neighboring groups when killing could be carried out safely. According to this idea chimpanzees and humans are equally risk-averse when fighting. When self-sacrificial war practices are found in (...) humans, therefore, they result from cultural systems of reward, punishment, and coercion rather than evolved adaptations to greater risk-taking. To test this “chimpanzee model,” we review intergroup fighting in chimpanzees and nomadic hunter-gatherers living with other nomadic hunter-gatherers as neighbors. Whether humans have evolved specific psychological adaptations for war is unknown, but current evidence suggests that the chimpanzee model is an appropriate starting point for analyzing the biological and cultural evolution of warfare. (shrink)

Although humans qualify as one of the most cooperative animal species, the scale of violent intergroup conflict among them is unparalleled. Explanations of the underlying motivations to participate in an intergroup conflict, however, remain unsatisfactory. While previous research shows that intergroup conflict increases individually costly behavior to the benefit of the in-group, it has failed to identify robust triggers of aggressive behavior directed at out-groups. Here, we present a controlled laboratory experiment which demonstrates that such aggression (...) can be provoked systematically by manipulating the extent to which the own group is perceived to be on the offensive or the defensive side of a conflict. We find direct and causal evidence that the motivation to protect the in-group is not only a predictor of retaliatory aggression, but also promotes preemptive offensive actions against out-groups if they pose a potential threat. This finding improves our understanding of the escalation of intergroup conflicts and may have important implications for their prevention, as we find in our experiment that removing out-group threat substantially reduced intergroup aggression and led to full peace. (shrink)

Although humans qualify as one of the most cooperative animal species, the scale of violent intergroup conflict among them is unparalleled. Explanations of the underlying motivation to participate in an intergroup conflict, however, remain unsatisfactory. While previous research shows that intergroup conflict increases ‘in-group love’, it fails to identify robust triggers of ‘out-group hate’. Here, we present a controlled laboratory experiment, which demonstrates that ‘out-group hate’ can be provoked systematically. We find direct and causal evidence that the (...) intention to protect the in-group is not only a crucial motivator of ‘out-group hate’ in defensive reactions, but also promotes preemptive offensive actions against out-group threat. Hence, the strength of ‘out-group hate’ depends on whether the own group is perceived to be on the offensive or the defensive side of the conflict. This finding improves our understanding of the escalation of intergroup conflicts and may have important implications for their prevention, as we find in our experiment that removing out-group threat substantially reduces intergroup aggression, leading to full peace. (shrink)

Dyadic play fighting occurs in many species, but only humans are known to engage in coalitional play fighting. Dyadic play fighting is hypothesized to build motor skills involved in actual dyadic fighting; thus, coalitional play fighting may build skills involved in actual coalitional fighting, operationalized as forager lethal raiding. If human psychology includes a motivational component that encourages engagement in this type of play, evidence of this play in forager societies is necessary to determine that it is not an artifact (...) of agricultural or industrial conditions. We examine whether coalitional play fighting appears in the hunter-gatherer record and includes motor skills used in lethal raiding. Using the ethnographic record, we generated a list of motor patterns regularly used in forager warfare. Then, using Murdock’s Ethnographic Atlas, we identified 100 culture clusters containing forager societies and searched the ethnographic records of these societies for descriptions of coalitional play fighting, operationalized as contact games played in teams. Resulting games were coded for the presence of eight motor patterns regularly used in forager lethal raiding. Although play does not tend to be systematically documented in the hunter-gatherer literature, sufficiently detailed descriptions of coalitional play were found for 46 of the 100 culture clusters: all 46 exhibited coalitional play using at least one of the predicted motor patterns; 39 exhibited coalitional play using four or more of the eight predicted motor patterns. These results provide evidence that coalitional play fighting occurs across a diverse range of hunter-gatherer cultures and habitats, regularly recruits motor patterns used in lethal raiding, and is not an artifact of agricultural or industrial life. This is a first step in a new line of research on whether human male psychology includes motivations to engage in play that develops the deployment of coordinated coalitional action involving key motor patterns used in lethal raiding. (shrink)

The target article offers a game-theoretical analysis of primitive intergroup aggression (i.e., raiding) and discusses difficulties in achieving peace. We argue the analysis does not capture the actual strategy space, missing out “do-nothing.” Experimental evidence robustly shows people prefer doing nothing against out-group members over cooperating with/attacking them. Thus, the target article overestimates the likelihood of intergroup aggression.

Drawing on an idea proposed by Darwin, it has recently been hypothesised that violent intergroup conflict might have played a substantial role in the evolution of human cooperativeness and altruism. The central notion of this argument, dubbed ‘parochial altruism’, is that the two genetic or cultural traits, aggressiveness against out-groups and cooperativeness towards the in-group, including self-sacrificial altruistic behaviour, might have coevolved in humans. This review assesses the explanatory power of current theories of ‘parochial altruism’. After a brief synopsis (...) of the existing literature, two pitfalls in the interpretation of the most widely used models are discussed: potential direct benefits and high relatedness between group members implicitly induced by assumptions about conflict structure and frequency. Then, a number of simplifying assumptions made in the construction of these models are pointed out which currently limit their explanatory power. Next, relevant empirical evidence from several disciplines which could guide future theoretical extensions is reviewed. Finally, selected alternative accounts of evolutionary links between intergroup conflict and intragroup cooperation are briefly discussed which could be integrated with parochial altruism in the future. (shrink)

The papers in this volume present varying approaches to human aggression, each from an evolutionary perspective. The evolutionary studies of aggression collected here all pursue aspects of patterns of response to environmental circumstances and consider explicitly how those circumstances shape the costs and benefits of behaving aggressively. All the authors understand various aspects of aggression as evolved adaptations but none believe that this implies we are doomed to continued violence, but rather that variation in aggression has (...) evolutionary roots. These papers reveal several similarities between human and nonhuman aggression, including our response to physical strength as an indicator of fighting ability, testosterone response to competition, a sensitivity to paternity, and baseline features of intergroup aggression in foragers and chimps. There is also one paper tackling the phylogeny of these traits. The many differences between human and nonhuman aggression are also pursued here. Topics here include the impact of modern weapons and extremes of wealth and power on both the costs and benefits of fighting, and the scale to which coercion can promote aggression that acts against a fighter’s own interests. Also the implications of large-scale human sociality are discussed. (shrink)

Literature shows that psychological phenomena, including values, personality, and behaviors, are geographically clustered. The effects of temperature on interpersonal and intergroup aggression have been studied by many social psychologists. To date the interactions between temperature and other geographical factors have not been addressed. This study is aiming to examine the effects of thermal demands and the moderating effects of natural geographical factors on aggressive behavior at national level. Data for 156 societies was obtained from publicly available databases. Consistent (...) with the life-history theory, results of this study showed that aggressive behavior has a positive relationship with heat demands, and a negative relationship with cold demands. Aggressive behavior is also positively correlated with sunlight and altitude, and negatively correlated with coastline vicinity. Forest, coastline vicinity, and rainfall moderated the effect of thermal demands on aggressive behavior. In societies with more forests, with more rainfall, and closer to coastline, the negative effects of cold demands on aggressive behavior are stronger. (shrink)

Here, we argue that attackers in intergroup conflicts are also likely to hold strong identity fusion, anticipate threat from the out-groups, and retaliate by signaling preemptive aggressiveness, which may not be asymmetrically exclusive to defenders. We propose that the study of the intergroup and intragroup dynamics could highlight more specific, robust markers to differentiate types of defenders from attackers.

People living in areas of intractable conflicts experience extreme negative emotions which ultimately lead to support of aggressive policies. Emotion regulation and particularly cognitive reapprais...

We focus on the implications of De Dreu and Gross's findings for the evolutionary perspective on out-group aggression and in-group cooperation. Although their experimental protocols are potentially useful in determining the origins of out-group aggression in humans, they so far provide inconclusive evidence only. We suggest ways of furthering our understanding of the connection between parochial cooperation and intergroup conflict.

The COVID-19 pandemic has caused a global societal, economic, and social upheaval unseen in living memory. There have been substantial cross-national differences in the kinds of policies implemented by political decision-makers to prevent the spread of the virus, to test the population, and to manage infected patients. Among other factors, these policies vary with politicians’ sex: early findings indicate that, on average, female leaders seem more focused on minimizing direct human suffering caused by the SARS-CoV-2 virus, while male leaders implement (...) riskier short-term decisions, possibly aiming to minimize economic disruptions. These sex differences are consistent with broader findings in psychology, reflecting women’s stronger empathy, higher pathogen disgust, health concern, care-taking orientation, and dislike for the suffering of other people—as well as men’s higher risk-taking, Machiavellianism, psychopathy, narcissism, and focus on financial indicators of success and status. This review article contextualizes sex differences in pandemic leadership in an evolutionary framework. Evolution by natural selection is the only known process in nature that organizes organisms into higher degrees of functional order, or counteracts the unavoidable disorder that would otherwise ensue, and is therefore essential for explaining the origins of human sex differences. Differential sexual selection and parental investment between males and females, together with the sexual differentiation of the mammalian brain, drive sex differences in cognition and behavioral dispositions, underlying men’s and women’s leadership styles and decision-making during a global pandemic. According to thesexually dimorphic leadership specialization hypothesis, general psychobehavioral sex differences have been exapted during human evolution to create sexually dimorphic leadership styles. They may be facultatively co-opted by societies and/or followers when facing different kinds of ecological and/or sociopolitical threats, such as disease outbreaks or intergroup aggression. Early evidence indicates that against the invisible viral foe that can bring nations to their knees, the strategic circumspection of empathic feminine health “worriers” may bring more effective and humanitarian outcomes than the devil-may-care incaution of masculine risk-taking “warriors”. (shrink)

Recent work on inheritance systems can be divided into inclusive conceptions, according to which genetic and non-genetic inheritance are both involved in the development and transmission of nearly all animal behavioral traits, and more demanding conceptions of what it takes for non-genetic resources involved in development to qualify as a distinct inheritance system. It might be thought that, if a more stringent conception is adopted, homologies could not subsist across two distinct inheritance systems. Indeed, it is commonly assumed that homology (...) relations cannot survive a shift between genetic and cultural inheritance systems, and substantial reliance has been placed on that assumption in debates over the phylogenetic origins of hominin behavioral traits, such as male-initiated intergroup aggression. However, in the homology literature it is widely accepted that a trait can be homologous—that is, inherited continuously in two different lineages from a single common ancestor—despite divergence in the mechanisms involved in the trait’s development in the two lineages. In this paper, we argue that even on an extremely stringent understanding of what it takes for developmental resources to form a separate inheritance system, homologies can nonetheless subsist across shifts between distinct inheritance systems. We argue that this result is a merit of this way of characterizing what it is to be an inheritance system, that it has implications for adjudicating between alternative accounts of homology, and that it offers an important cautionary lesson about how to reason with the homology concept, particularly in the context of cultural species. (shrink)

Conflict can profoundly affect individuals and their groups. Oftentimes, conflict involves a clash between one side seeking change and increased gains through victory and the other side defending the status quo and protecting against loss and defeat. However, theory and empirical research largely neglected these conflicts between attackers and defenders, and the strategic, social, and psychological consequences of attack and defense remain poorly understood. To fill this void, we model (1) the clashing of attack and defense as games of strategy (...) and reveal that (2) attack benefits from mismatching its target's level of defense, whereas defense benefits from matching the attacker's competitiveness. This suggests that (3) attack recruits neuroendocrine pathways underlying behavioral activation and overconfidence, whereas defense invokes neural networks for behavioral inhibition, vigilant scanning, and hostile attributions; and that (4) people invest less in attack than defense, and attack often fails. Finally, we propose that (5) in intergroup conflict, out-group attack needs institutional arrangements that motivate and coordinate collective action, whereas in-group defense benefits from endogenously emerging in-group identification. We discuss how games of attack and defense may have shaped human capacities for prosociality and aggression, and how third parties can regulate such conflicts and reduce their waste. (shrink)

In this introduction to the first installment of the Common Knowledge symposium on xenophilia, the editor explains the rationale of the new project, citing increases in aggressive xenophobia internationally. He comments on the intergroup-relations theorist Todd Pittinsky's argument that, since tolerance is not logically the antithesis of negative feelings toward out-groups, even long-established traditions of toleration are inadequate to prevent intergroup aggression. Pittinsky proposes that tolerance be replaced, as a principle of peacekeeping, by the encouragement of positive (...) feelings toward out-groups, and the author of this essay responds by showing how the Freudian theory of ambivalence and the history of literature on which Freud drew in constructing it support Pittinsky's viewpoint. Enemies regularly fall in love, above all in Shakespearean drama, which Freud explains by arguing that all human relations are love-hate relations. Thus, this essay suggests, it takes as much psychic energy to repress the love in what appear to be relationships of hatred as to repress the hatred in what appear to be relationships of love. There is a metaphysical component as well to this argument: the xenophobe and xenophile equally presuppose that the identity principle is applicable to society as well as to mathematics; both assume that each discrete social group is self-identical and differs from all other groups more or less radically. The main difference between –phile and –phobe is the latter's relative incapacity to live with ambivalence. Given these arguments, one must expect to find negative as well as positive motives in the etiology and conduct of xenophilia—and the first installment of the Common Knowledge symposium is said to focus on cases of xenophilia in which varieties of enmity accompany that singular and underrated variety of love. (shrink)

This paper focuses on the deployment and interdependence of different expressions of gendered and classed violence in shaping the choices, trajectories and subjectivities of young women on vocational beauty therapy courses. It takes as its premise the understanding that, far from simply being an aberrant expression of interpersonal or intergroup aggression, violence is embedded in social life in multiple and complex ways, reverberating through women's lives to reproduce disadvantage and subordination. The paper draws on theoretical and empirical investigations (...) of the interrelationships between structural, direct and symbolic expressions of violence and asks what this literature can offer in challenging normative, often individualised, conceptions of violence. Drawing on an ethnographic case study of National Vocational Qualification (NVQ) beauty therapy courses and the young women undertaking them, I explore the accounts of students and their tutors on becoming and being ‘beauty girls’. I consider what these accounts might tell us about how forms of symbolic and interpersonal violence intersect with, reproduce and legitimise the violence involved in unequal and unjust socio-economic structures. I argue that the ways in which different forms of violence mutually reinforce each other at a micro-level produce an embodied ‘sense of limits’ that ultimately reproduces the structural violence of gendered and classed inequalities. The examples given illustrate both a ‘chronology of violence’ in young women's lives, and the way in which those lives can be understood, at least in part, as embedded in and shaped by networks of violence. Finally, I briefly consider examples of dissent and resistance, the conditions under which they might be possible and the ways in which, through the interplay of different forms of violence, they might also be curtailed. (shrink)

The perceived support of supernatural agents has been historically, ethnographically, and theoretically linked with confidence in engaging in violent intergroup conflict. However, scant experimental investigations of such links have been reported to date, and the extant evidence derives largely from indirect laboratory methods of limited ecological validity. Here, we experimentally tested the hypothesis that perceived supernatural aid would heighten inclinations toward coalitional aggression using a realistic simulated coalitional combat paradigm: competitive team paintball. In a between-subjects design, US paintball (...) players recruited for the study were experimentally primed with thoughts of supernatural support using a guided visualization exercise analogous to prayer, or with a control visualization of a nature scene. The participants then competed in a team paintball battle game modeled after “Capture the Flag.” Immediately before and after the battle, participants completed surveys assessing confidence in their coalitional and personal battle performance. Participants assessed their coalition’s prospects of victory and performance more positively after visualizing supernatural aid. Participants primed with supernatural support also reported inflated assessments of their own performance. Importantly, however, covarying increases in assessments of their overall coalition’s performance accounted for the latter effect. This study provided support for the hypothesis that perceived supernatural support can heighten both prospective confidence in coalitional victory and retrospective confidence in the combat performance of one’s team, while highlighting the role of competitive play in evoking the coalitional psychology of intergroup conflict. These results accord with and extend convergent prior findings derived from laboratory paradigms far removed from the experience of combat. Accordingly, the field study approach utilized here shows promise as a method for investigating coalitional battle dynamics in a realistic, experientially immersive manner. (shrink)

While some species have affiliative and even cooperative interactions between individuals of different social groups, humans are alone in having durable, positive-sum, interdependent relationships across unrelated social groups. Our capacity to have harmonious relationships that cross group boundaries is an important aspect of our species' success, allowing for the exchange of ideas, materials, and ultimately enabling cumulative cultural evolution. Knowledge about the conditions required for peaceful intergroup relationships is critical for understanding the success of our species and building a (...) more peaceful world. How do humans create harmonious relationships across group boundaries and when did this capacity emerge in the human lineage? Answering these questions involves considering the costs and benefits of intergroup cooperation and aggression, for oneself, one's group, and one's neighbor. Taking a game theoretical perspective provides new insights into the difficulties of removing the threat of war and reveals an ironic logic to peace – the factors that enable peace also facilitate the increased scale and destructiveness of conflict. In what follows, I explore the conditions required for peace, why they are so difficult to achieve, and when we expect peace to have emerged in the human lineage. I argue that intergroup cooperation was an important component of human relationships and a selective force in our species history beginning at least 300 thousand years. But the preconditions for peace only emerged in the past 100 thousand years and likely coexisted with intermittent intergroup violence which would have also been an important and selective force in our species' history. (shrink)

We report three studies which test a sexual selection hypothesis for male war heroism. Based on evolutionary theories of mate choice we hypothesize that men signal their fitness through displaying heroism in combat. First, we report the results of an archival study on US-American soldiers who fought in World War II. We compare proxies for reproductive success between a control sample of 449 regular veterans and 123 surviving Medal of Honor recipients of WWII. Results suggest that the heroes sired more (...) offspring than the regular veterans. Supporting a causal link between war heroism and mating success, we then report the results of two experimental studies. We find evidence that female participants specifically regard men more sexually attractive if they are war heroes. This effect is absent for male participants judging female war heroes, suggesting that bravery in war is a gender specific signal. Finally, we discuss possible implications of our results. (shrink)

Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal (...) models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor. (shrink)

Economic games provide models of real-world contexts in which researchers can probe dispositional and structural determinants of intergroup relations. Most intergroup games focus on determinants of aggression between groups and constrain the possibilities for peace. However, paradigms such as the intergroup parochial and universal cooperation game allow for peaceful intergroup relations and can be adapted for the study of peace.

McCullough et al. argue that humans possess evolved computational systems for implementing retaliatory behavior that both deters aggression and promotes subsequent reconciliation. However, they do not apply this analysis to the sphere of intergroup relations. We believe their model can be usefully extended to this domain and discuss why this would be possible, pertinent, and productive.

Humans are one of the most cooperative and altruistic species on the planet. At the same time, humans have a long history of violent and deadly intergroup conflicts, i.e. wars. Recently, contemporary evolutionary theorists have revived Charles Darwin’s idea that human in-group altruism and out-group hostility might have co-evolved. Groups with more cooperatively aggressive men, they suggest, were more likely to prevail in the frequent lethal quarrels of human pre-history, and these men, therefore, more likely to have passed on (...) their genes. After a short introduction to evolutionary perspectives on war heroism, we describe selected characteristics of 988 modern war heroes, the US-American Medal of Honor recipients of WWI, WWII, the Korean and the Vietnam War, and discuss whether an evolutionary perspective can help us understand why these men risked their lives ‘beyond the call of duty’. (shrink)

The evolution of altruism in human societies has been intensively investigated in social and natural sciences. A widely acknowledged recent idea is the “parochial altruism model,” which suggests that inter- group hostility and intragroup altruism can coevolve through lethal intergroup conflicts. The current article critically examines this idea by reviewing research relevant to intergroup conflicts in human evolutionary history from evolutionary biology, psychology, cultural anthropology, and archaeology. After a brief intro- duction, section 2 illustrates the mathematical model of (...) parochial altruism and some critiques of the model and its interpretation, primarily from an evolutionary biology point of view. Section 3 delves into the archaeological evidence of prehistoric intergroup conflicts in the Japanese archipelago’s Jomon and Yayoi periods, Europe’s Mesolithic period, and North America’s Pacific period as counter examples of the paro- chial altruism model. In section 4, the ethnographies of intergroup relationships and conflicts reveal that intergroup relationships in many ethnic groups are not as simple as the assumption in the mathematical model of parochial altruism. In section 5, we outline psychological research on intergroup conflicts which suggest that intergroup hostility and ingroup altruism are not necessarily correlated. In conclusion, we argue that the assumption and parameter settings of the parochial altruism model are inconsistent with empirical data. (shrink)

Aggressive behavior is instinctively driven behavior that helps animals to survive and reproduce and is closely related to multiple behavioral and physiological processes. The dorsal raphe nucleus (DRN) is an evolutionarily conserved midbrain structure that regulates aggressive behavior by integrating diverse brain inputs. The DRN consists predominantly of serotonergic (5‐HT:5‐hydroxytryptamine) neurons and decreased 5‐HT activity was classically thought to increase aggression. However, recent studies challenge this 5‐HT deficiency model, revealing a more complex role for the DRN 5‐HT system in (...) aggression. Furthermore, emerging evidence has shown that non‐5‐HT populations in the DRN and specific neural circuits contribute to the escalation of aggressive behavior. This review argues that the DRN serves as a multifaceted modulator of aggression, acting not only via 5‐HT but also via other neurotransmitters and neural pathways, as well as different subsets of 5‐HT neurons. In addition, we discuss the contribution of DRN neurons in the behavioral and physiological aspects implicated in aggressive behavior, such as arousal, reward, and impulsivity, to further our understanding of DRN‐mediated aggression modulation. (shrink)

Intergroup and long-distance relationships are both central features of human social life, but because intergroup relationships are emphasized in the literature, long-distance relationships are often overlooked. Here, we make the case that intergroup and long-distance relationships should be studied as distinct, albeit related, features of human sociality. First, we review the functions of both kinds of relationship: while both can be conduits for difficult-to-access resources, intergroup relationships can reduce intergroup conflict whereas long-distance relationships are especially (...) effective at buffering widespread resource shortfalls. Second, to illustrate the importance of distinguishing the two relationship types, we present a case study from rural Bolivia. Combining ethnography and two different experimental techniques, we find that the importance of intergroup relationships—and the salience of group membership itself—varies across populations and across methods. Although ethnography revealed that participants often rely on long-distance relationships for resource access, we were unable to capture participant preferences for these relationships with a forced-choice technique. Taken together, our review and empirical data highlight that (1) intergroup and long-distance relationships can have different functions and can be more or less important in different contexts and (2) validating experimental field data with ethnography is crucial for work on human sociality. We close by outlining future directions for research on long-distance relationships in humans. (shrink)

Male aggression against females in primates, including humans, often functions to control female sexuality to the male’s reproductive advantage. A comparative, evolutionary perspective is used to generate several hypotheses to help to explain cross-cultural variation in the frequency of male aggression against women. Variables considered include protection of women by kin, male-male alliances and male strategies for guarding mates and obtaining adulterous matings, and male resource control. The relationships between male aggression against women and gender ideologies, male (...) domination of women, and female sexuality are also considered. (shrink)

In this paper, I investigate intergroup relations between natives and asylum seekers during the European refugee crisis, and contribute to the reemerging methodological debate on the measurement of stereotypes and prejudices as individual and collective constructs. Drawing on data from the Norwegian Citizen Panel, I examined how Norwegians stereotyped asylum seekers at the height of the refugee crisis and the emotional prejudices asylum seekers as a group elicited. By experimentally manipulating the survey question format, I examined whether and how (...) stereotypes and emotional prejudices toward asylum-seekers differed depending on their measurement as individual or collective constructs. A subset of respondents had reception centers for asylum-seekers established in their local community during the crisis. These participants reported their behaviors toward the asylum seekers in their neighborhood. In this subsample, I investigated how individual facilitating and harming intergroup behavior was related to individual and collective conceptualizations of stereotypes and prejudices. The results showed that both low warmth and low competence stereotypes, as well as negative emotions toward asylum seekers, were rated as stronger when measured as collective as compared to individual-level constructs. In the individual condition, respondents reported feeling more admiration and sympathy than respondents in the collective condition attributed to others. Individual stereotypes and prejudices correlated systematically with individual facilitating and harming intergroup behaviors. The perception that others hold more negative stereotypes of asylum seekers, and the perceived anger and fear of others, did correlated with individual harming behaviors. Perceptions of others’ anxiety correlated negatively with facilitating behaviors. Implications and future directions for the conceptualization and measurement of stereotypes and emotional prejudices are discussed. (shrink)

Although the effect of religious belief on morally relevant behavior is well demonstrated, the reverse influence is less known. In this research, we examined the influence of morality on religious belief. In the first study, we used two samples from Turkey and the United States, and specifically tested the hypothesis that intergroup tolerance predicts a shift in meta-ethical views toward subjective morality, which in turn predicts decreased religious belief. To examine the relationship between intergroup tolerance and religiosity via (...) subjective morality, a structural equation model (SEM) was run. SEM results yielded good fit to the data for both samples. Intergroup tolerance positively predicted subjective morality, and in turn, morality negatively predicted religiosity. The bias-corrected bootstrap analysis confirmed the mediation, indicating that the association between intergroup tolerance and religious belief was mediated via subjective morality. In Study 2, we probed for the causal relationship, and the results showed that manipulating intergroup tolerance increases subjective morality, but does not influence religiosity. Therefore, we found only partial evidence for our proposed model that tolerance causally influences subjective morality, but not religiosity. (shrink)

Aggressive techniques within casual sex encounters, such as taking sexual liberties without permission or ignoring rejection, can, perhaps unintentionally, complicate consent. Passive recipients may acquiesce out of fear, which aggressors may not realize. Some philosophers argue that social norms are sufficiently well known to make this misunderstanding unlikely. However, the chance of aggression leading to non-consensual sex, even if not great, is high enough that aggressors should work diligently to avoid this potentially grave result. I consider how this problem (...) plays out in the common mating ritual of hooking up. I argue that aggressive hook ups can only be permissible if they are modeled on BDSM encounters: the participants must obtain prior consent and prepare safe words for voiding that consent during the hook up. While this solution removes the spontaneity of aggressive sex, I argue that spontaneously aggressive hook ups with strangers cannot be permissible. (shrink)

Is reducing large-scale intergroup conflict the business of corporations? Although large corporations can use their power and prominence to reduce intergroup conflict in society, it is unclear to what extent stakeholders support corporate Intergroup Responsibility. Study 1 showed that support for CIR correlates in theoretically meaningful ways with relevant economic, social, and moral attitudes, including fair market ideology, consumer support for corporate social responsibility, social dominance orientation, symbolic racism, and moral foundations. Studies 2 and 3 employed experimental (...) designs to test the hypothesis that business leaders who advocate for intergroup tolerance boost perceptions of corporations and their leaders as moral, just, and fair, which in turn, increases stakeholders’ support for CIR. We found support for this hypothesis across two highly publicized and contentious events related to racial conflict in the U.S.: The White supremacy rally in Charlottesville and the federal government’s announcement about the planned rescinding of the Deferred Action for Childhood Arrivals immigration policy. Specifically, exposing participants to real-world tweets by CEOs who advocated intergroup tolerance following these events increased participants’ support for CIR. This effect was mediated by heightened perceptions of corporations and their leaders as moral, just, and fair. Taken together, these findings enhance our understanding of the factors that shape stakeholders’ reactions to CIR; highlight intergroup conflict as an emerging arena for CSR; and illustrate the power of ethical intergroup leadership. (shrink)

Whereas many evolutionary models emphasize within-group cooperation or between-group competition in explaining human large-scale cooperation, recent work highlights a critical role for intergroup cooperation in human adaptation. Here we investigate intergroup cooperation in the domain of shotgun hunting in northern Republic of the Congo. In the Congo Basin broadly, forest foragers maintain relationships with neighboring farmers based on systems of exchange regulated by norms and institutions such as fictive kinship. In this study, we examine how relationships between Yambe (...) farmers and BaYaka foragers support stable intergroup cooperation in the domain of shotgun hunting. In the study village, shotgun hunting is based on a specialization-based exchange wherein Yambe farmers contribute shotguns and access to markets to buy cartridges and sell meat while BaYaka foragers contribute their specialized forest knowledge and skill. To understand how costs and benefits are distributed, we conducted structured interviews with 77 BaYaka hunters and 15 Yambe gun owners and accompanied hunters on nine hunting trips. We found that hunts are organized in a conventional manner within a fictive kinship structure, consistent with the presence of intercultural mechanisms to stabilize cooperation. However, because bushmeat demand is high, gun owners can gain significant cash profit, while compensating hunters only with cigarettes, alcohol, and a traditional hunter’s portion of meat. To level payoffs, hunters strategically hide kills or cartridges from gun owners to feed their own families. Our results illustrate how each group prioritizes different currencies (e.g., cash, meat, family, intergroup relations) and provide insights into how intergroup cooperation is stabilized in this setting. The example of this long-standing intergroup cooperative system is discussed in terms of its contemporary entwinement with logging, the bushmeat trade, and growing market intersection. (shrink)

Sex differences in physical and indirect aggression have been found in many societies but, to our knowledge, have not been studied in a population of hunter-gatherers. Among Aka foragers of the Central African Republic we tested whether males physically aggressed more than females, and whether females indirectly aggressed more than males, as has been seen in other societies. We also tested predictions of an evolutionary theory of physical strength, anger, and physical aggression. We found a large male bias (...) in physical aggression. Controlling for anger, we found an adult female bias in indirect aggression. Physical strength predicted anger, which predicted hitting, although results were sensitive to the inclusion or exclusion of traditional healers, who were physically and emotionally distinct from other Aka. With some important caveats, our results generally support the predicted sex differences in physical aggression and indirect aggression, and the predicted relationships among anger, strength, and aggression. (shrink)

In this volume, the third in his trilogy on the philosophical and legal aspects of war and conflict, Larry May locates a normative grounding for the crime of aggression - the only one of the three crimes charged at Nuremberg that is not currently being prosecuted - that is similar to that for crimes against humanity and war crimes. He considers cases from the Nuremberg trials, philosophical debates in the Just War tradition, and more recent debates about the International (...) Criminal Court, as well as the hard cases of humanitarian intervention and terrorist aggression. His thesis refutes the traditional understanding of aggression. At Nuremberg, crimes against humanity charges were only pursued if the defendant also engaged in the crime of aggression. May argues for a reversal of this position, contending that aggression charges should be pursued only if the defendant's acts involve serious human rights violations. (shrink)

Hospitals are places where patients are unwell, where patients and their families may be upset, confused, frustrated, in pain, and vulnerable. The likelihood of these experiences and emotions manifesting in anger and aggressive behaviour is high. In this paper, we describe the involvement of a clinical ethics service responding to a request to discuss family aggression within a rehabilitation department in a large paediatric hospital in Australia. We suggest two key advantages of involving a clinical ethics service in discussions (...) about how to respond to family aggression. First, the process of ethics deliberation provides an opportunity for clinicians to be involved in the solution by articulating their perspectives, tolerance levels, and general concerns about the effects of family aggression towards staff. Second, supporting clinicians to articulate and identify the impact of parental aggression directly counters the disadvantages of the more blunt zero-tolerance policy response, which is necessarily imposed from the top down. (shrink)

Some people report that they argue for play. We question whether and how often such arguments are mutually entertaining for both participants. Play is a frame for arguing, and the framing may not always be successful in laminating the eristic nature of interpersonal argumentation. Previous research and theory suggest that playfulness may be associated with aggression. Respondents supplied self - report data on their arguing behaviors and orientations. We found support for the hypothesis that self - reported playfulness and (...) aggression are directly associated. We found less evidence for our hypothesized inverse association between self - reported playfulness and indices of cooperation and avoidance. Self - reports of playfulness are not significantly associated with expert coders ’ ratings of either playfulness or aggressiveness. The claim that an argument is playful should be met with skepticism, although playful arguments are possible. (shrink)

This is the conundrum that gives rise to the issue of tax avoidance: Although governments always seem to lack sufficient funds to support the needs of society, tax codes are often written that offer “a way out” of paying taxes for some but not all constituents. The ways out are referred to as loopholes that allow taxpayers to avoid taxes. This paper first defines the basic terms of tax avoidance and tax evasion and then offers an ethical review of the (...) morality of aggressive tax avoidance. Aggressive tax avoidance is then addressed in relationship a corporate entity’s tone at the top. The conclusion is drawn that use of the letter of the law to avoid payment of taxes sorely needed by governments for the good faith provision of public goods and services is ethically unacceptable. Several suggestions for change are provided, including a new financial statement disclosure and the possibility of a published corporate ethics report. (shrink)

First published in 2001. Routledge is an imprint of Taylor & Francis, an informa company.

Hugely controversial on publication, this is an insightful and characteristically entertaining survey of animal behaviour and the evolution of aggression throughout the animal world.

Fundamental problems of environmental sustainability, including climate change and fisheries management, require collective action on a scale that transcends the political and cultural boundaries of the nation-state. Rational, self-interested neoclassical economic theories of human behavior predict tragedy in the absence of third party enforcement of agreements and practical difficulties that prevent privatization. Evolutionary biology offers a theory of cooperation, but more often than not in a context of discrimination against other groups. That is, in-group boundaries are necessarily defined by those (...) excluded as members of out-groups. However, in some settings human’s exhibit behavior that is inconsistent with both rational economic and group driven cooperation of evolutionary biological theory. This paper reports the results of a non-cooperative game-theoretic exercise that models a tragedy of the commons problem in which groups of players may advance their own positions only at the expense of other groups. Students enrolled from multiple universities and assigned to different multi-university identity groups participated in experiments that repeatedly resulted in cooperative outcomes despite intergroup conflicts and expressions of group identity. We offer three possible explanations: students were cooperative because they were in an academic setting; students may have viewed their instructors as the out-group; or the emergence of a small number of influential, ethical leaders is sufficient to ensure cooperation amongst the larger groups. From our data and analysis, we draw out lessons that may help to inform approaches for institutional design and policy negotiations, particularly in climate change management. (shrink)