A mutualistic approach to morality: The evolution of fairness by partner choice

When rules are over-ruled: Virtual bargaining as a contractualist method of moral judgment

Rules help guide our behavior-particularly in complex social contexts. But rules sometimes give us the "wrong" answer. How do we know when it is okay to break the rules? In this paper, we argue that we sometimes use contractualist (agreement-based) mechanisms to determine when a rule can be broken. Our model draws on a theory of social interactions - "virtual bargaining" - that assumes that actors engage in a simulated bargaining process when navigating the social world. We present experimental data which suggests that rule-breaking decisions are sometimes driven by virtual bargaining and show that these data cannot be explained by more traditional rule-based or outcome-based approaches.

Beyond broad and narrow: Intermediate level traits in the personality of bridge players

Games offer a unique context for studying human behavior within the realm of social interactions, where a crucial aspect is the role of personality. The personality of individuals is often conceptualized as divided between general traits (broad traits) that are difficult to apply to specific situations and highly specific traits (narrow traits) that only offer a partial depiction of contextual aspects. In this study, we propose an intermediary level of traits revealed through self-ratings (as broad traits), but defined with respect to a particular game context (as narrow traits). We focus on the popular game of Bridge, which is complex and similar to real-life interactions involving incomplete information, adversarial and cooperative concerns, and communication between players. Using a multidimensional analysis of a new 66-item Bridge Inventory survey completed by 1,300 players, we identified five factors (Aggressiveness, Discipline, Creativity, Emotionality, and Experience) that were meaningfully correlated with broad traits of the Five Factor Model (FFM), supporting their validity. Based on these game-related traits, we identified three types of Bridge players: Conventional, Measured, and Subversive and demonstrated the limitations of FFM traits in capturing nuances of player types. The results of our study highlight a discrepancy between broad, context-independent personality traits and narrow, game-specific traits. We propose that this gap can be bridged through self-ratings, revealing a set of intermediate-level, context-dependent traits, which are expected to better encompass interindividual variability in the context of social interactions.

Contractualist tendencies and reasoning in moral judgment and decision making

The social-contract tradition of Hobbes, Rousseau, Kant, and Rawls has been widely influential in moral philosophy but has until recently received relatively little attention in moral psychology. For contractualist moral theories, ethics is a matter of forming, adhering to, and enforcing (hypothetical) agreements, and morality is fundamentally about acting according to what would be agreed by rational agents. A recent psychological theory, virtual bargaining, models social interactions in contractualist terms, suggesting that we often act as we would agree to do if we were to negotiate explicitly. However, whether such contractualist tendencies (a propensity to make typically contractualist choices) and forms of reasoning (agreement-based cognitive processes) play a role in moral cognition is still unclear. Drawing upon virtual bargaining, we develop two novel experimental paradigms designed to elicit incentivized decisions and moral judgments. We then test the descriptive relevance of contractualism in moral judgment and decision making in five preregistered online experiments (n = 4103; English-speaking Prolific participants). In the first task, we find evidence that many participants show contractualist tendencies: their choices are "characteristically" contractualist. In the second task, we find evidence consistent with contractualist reasoning influencing some participants' judgments and incentivized decisions. Our findings suggest that a propensity to act as prescribed by tacit agreements may be particularly important in understanding the moral psychology of fleeting social interactions and coordination problems. By complementing the rich literature on deontology and consequentialism in moral psychology, empirical approaches inspired by contractualism may prove fruitful to better understand moral cognition.

Evidence for core social goal understanding (and, perhaps, core morality) in preverbal infants

Spelke's What Babies Know masterfully describes infants' impressive repertoire of core cognitive concepts, from which the suite of human knowledge is eventually built. The current commentary argues for the existence of a core concept that Spelke claims preverbal infants lack: social goal. Core social goal concepts, operative extremely early in human development, underlie infants' basic abilities to interpret and evaluate entities within the moral world; such abilities support claims for a core moral domain.

Similarity Among Friends Serves as a Social Prior: The Assumption That "Birds of a Feather Flock Together" Shapes Social Decisions and Relationship Beliefs

Social interactions unfold within networks of relationships. How do beliefs about others' social ties shape-and how are they shaped by-expectations about how others will behave? Here, participants joined a fictive online game-playing community and interacted with its purported members, who varied in terms of their trustworthiness and apparent relationships with one another. Participants were less trusting of partners with untrustworthy friends, even after they consistently showed themselves to be trustworthy, and were less willing to engage with them in the future. To test whether people not only expect friends to behave similarly but also expect those who behave similarly to be friends, an incidental memory test was given. Participants were exceptionally likely to falsely remember similarly behaving partners as friends. Thus, people expect friendship to predict similar behavior and vice versa. These results suggest that knowledge of social networks and others' behavioral tendencies reciprocally interact to shape social thought and behavior.

Motor coordination induces social identity-A novel paradigm for the investigation of the group performance-identity link

Joint action theorizing implies that any coordinated behaviour that induces co-representation with a partner should increase social identification, especially when the associated actions require a high degree of coordination and are experienced as being performed effectively. The current research provides a first test of this new theoretical prediction for complementary (rather than synchronous) joint actions. In each of two pre-registered experiments establishing a novel paradigm, participants performed a digital joystick task with a joint performance goal with three different partners. The task varied in coordination requirements across partners. In Experiment 1, results showed that when task segments were discrete between partners, they identified less as a group than when they had to coordinate their behaviour. Surprisingly, although constant coordination increased co-representation relative to intermittent coordination, it did not correspondingly increase social identification. However, performance correlated positively with identification; as performance was worse when participants had to coordinate, this may explain the results. Experiment 2 showed that performance is causally linked to identification when coordination is necessary. Taken together, our results suggest that experiencing effective coordination leads to greater social identification. In general, paradigms capable of examining the perceptual and motor aspects of collective behaviour may offer a new perspective on social identification in general and the performance-identification link in particular.

Evolution of spite versus evolution of altruism through a disbandment mechanism

Altruism and spite are costly to the actor, making their evolution unlikely without specific mechanisms. Nonetheless, both altruistic and spiteful behaviors are present in individuals, which suggests the existence of an underlying mechanism that drives their evolution. If altruistic individuals are more likely to be recipients of altruism than non-altruistic individuals, then altruism can be favored by natural selection. Similarly, if spiteful individuals are less likely to be recipients of spite than non-spiteful individuals, then spite can be favored by natural selection. Spite is altruism's evil twin, ugly sister of altruism, or a shady relative of altruism. In some mechanisms, such as repeated interactions, if altruism is favored by natural selection, then spite is also favored by natural selection. However, there has been limited investigation into whether both behaviors evolve to the same extent. In this study, we focus on the mechanism by which individuals choose to keep or stop the interaction according to the opponent's behavior. Using the evolutionary game theory, we investigate the evolution of altruism and spite under this mechanism. Our model revealed that the evolution of spite is less likely than the evolution of altruism.

Justice at the Forefront: Cultivating felt accountability towards Artificial Intelligence among healthcare professionals

The advent of AI has ushered in a new era of patient care, but with it emerges a contentious debate surrounding accountability for algorithmic medical decisions. Within this discourse, a spectrum of views prevails, ranging from placing accountability on AI solution providers to laying it squarely on the shoulders of healthcare professionals. In response to this debate, this study, grounded in the mutualistic partner choice (MPC) model of the evolution of morality, seeks to establish a configurational framework for cultivating felt accountability towards AI among healthcare professionals. This framework underscores two pivotal conditions: AI ethics enactment and trusting belief in AI and considers the influence of organizational complexity in the implementation of this framework. Drawing on Fuzzy-set Qualitative Comparative Analysis (fsQCA) of a sample of 401 healthcare professionals, this study reveals that a) focusing justice and autonomy in AI ethics enactment along with building trusting belief in AI reliability and functionality reinforces healthcare professionals' sense of felt accountability towards AI, b) fostering felt accountability towards AI necessitates ensuring the establishment of trust in its functionality for high complexity hospitals, and c) prioritizing justice in AI ethics enactment and trust in AI reliability is essential for low complexity hospitals.

The deflationary model of harm and moral wrongdoing: A rejoinder to Royzman & Borislow

With a series of studies, Royzman and Borislow (2022) purport to show that extant models about the conditions under which harmful actions are deemed morally wrong do not have explanatory power-for any proposed condition, various harmful actions meet the condition but are not deemed immoral. And they reach the following conclusion: judgments of moral wrongdoing in the context of harmful actions (or judgments of moral wrongdoing more generally) are not reducible to an explanatory template. However, they did not address the main claim of the deflationary model of harm and moral wrongdoing, which is that intuitions of injustice connect harmful actions to judgments of moral wrongdoing (Sousa & Piazza, 2014). Our first study adjusts Royzman and Borislow' design to include a measure of perceived injustice, while our second elaborates their design to manipulate perceived injustice. The results undermine their conclusion and support the deflationary model, which we further refine here in light of the results of Royzman and Borislow's studies and ours.

Chimpanzees engage in competitive altruism in a triadic ultimatum game

Partner choice promotes competition among individuals to be selected as a cooperative partner, a phenomenon referred to as competitive altruism. We explored whether chimpanzees engage in competitive altruism in a triadic Ultimatum Game where two proposers can send offers simultaneously or consecutively to a responder who can only accept one of the two competing offers. In a dyadic control condition only one proposer at a time could send an offer to the responder. Chimpanzees increased their offers across trials in the competitive triadic, but not in the dyadic control condition. Chimpanzees also increased their offers after being rejected in previous triadic trials. Furthermore, we found that chimpanzees, under specific conditions, outcompete first proposers in triadic consecutive trials before the responder could choose which offer to accept by offering more than what is expected if they acted randomly or simply offered the smallest possible amount. These results suggest that competitive altruism in chimpanzees did not emerge just as a by-product of them trying to increase over previous losses. Chimpanzees might consider how others' interactions affect their outcomes and engage in strategies to maximize their chances of being selected as cooperative partners.

Computational Social Psychology

Social psychologists attempt to explain how we interact by appealing to basic principles of how we think. To make good on this ambition, they are increasingly relying on an interconnected set of formal tools that model inference, attribution, value-guided decision making, and multi-agent interactions. By reviewing progress in each of these areas and highlighting the connections between them, we can better appreciate the structure of social thought and behavior, while also coming to understand when, why, and how formal tools can be useful for social psychologists.

From Envy to Radicalization

Models of radicalization have typically placed grievances at the heart of radicalization. In contrast, we argue that viewing the radicalizing agent as decidedly proactive, and less reactive, better accounts for the available data. At the core of our radicalization model is the functional structure of envy. The operative properties of the emotion align with essential and conspicuous features of the radicalization process: a motivation to monitor social differentials, an identification of sources of postulated welfare costs, an impulse to eliminate or depower purported competitors, an attempt to diffuse responsibility for one's aggressive actions, and the rejoicing at the envied agent's misfortune. Two of those operative properties are particularly important for our understanding of radicalization. Envy motivates the neutralization of competitors when responsibility for welfare costs is not objectively attributable to others' wrongdoing toward the party who feels injured. The "process of typification" serves as a means to diffuse responsibility. It extends the reach of individual concerns by downplaying the particulars of the personal situation motivating the envious agent while evoking universally shared interaction templates (e.g., humiliation, injustice) to appeal to a broader audience.

Guinea baboons are strategic cooperators

Humans are strategic cooperators; we make decisions on the basis of costs and benefits to maintain high levels of cooperation, and this is thought to have played a key role in human evolution. In comparison, monkeys and apes might lack the cognitive capacities necessary to develop flexible forms of cooperation. We show that Guinea baboons (Papio papio) can use direct reciprocity and partner choice to develop and maintain high levels of cooperation in a prosocial choice task. Our findings demonstrate that monkeys have the cognitive capacities to adjust their level of cooperation strategically using a combination of partner choice and partner control strategies. Such capacities were likely present in our common ancestor and would have provided the foundations for the evolution of typically human forms of cooperation.

Partner choice and cooperation in social dilemmas can increase resource inequality

Cooperation is more likely when individuals can choose their interaction partner. However, partner choice may be detrimental in unequal societies, in which individuals differ in available resources and productivity, and thus in their attractiveness as interaction partners. Here we experimentally examine this conjecture in a repeated public goods game. Individuals (n = 336), participating in groups of eight participants, are assigned a high or low endowment and a high or low productivity factor (the value that their cooperation generates), creating four unique participant types. On each round, individuals are either assigned a partner (assigned partner condition) or paired based on their self-indicated preference for a partner type (partner choice condition). Results show that under partner choice, individuals who were assigned a high endowment and high productivity almost exclusively interact with each other, forcing other individuals into less valuable pairs. Consequently, pre-existing resource differences between individuals increase. These findings show how partner choice in social dilemmas can amplify resource inequality.

Ownership psychology, its antecedents and consequences

Commentators discussed the coherence and validity of a minimalist approach to ownership intuitions, in ways that make it possible to clarify the model, re-evaluate its cognitive underpinnings, and sketch some of its implications. This response summarizes the model; addresses issues concerning the need for a special technical lexicon when describing cognitive semantics; the psychology involved in contexts of competitive acquisition and their consequences for possession and use of rival resources; the role of cooperative expectations in creating mutually beneficial allocation of resources; the consequences of ownership psychology for social interaction and the production of social norms of property; and the relations between psychological processes and legal institutions in the domain, before proposing some final thoughts.

The puritanical moral contract: Purity, cooperation, and the architecture of the moral mind

Commentators raise fundamental questions about the notion of purity (sect. R1), the architecture of moral cognition (sect. R2), the functional relationship between morality and cooperation (sect. R3), the role of folk-theories of self-control in moral judgment (sect. R4), and the cultural variation of morality (sect. R5). In our response, we address all these issues by clarifying our theory of puritanism, responding to counter-arguments, and incorporating welcome corrections and extensions.

Rational inferences about social valuation

The decisions made by other people can contain information about the value they assign to our welfare-for example how much they are willing to sacrifice to make us better off. An emerging body of research suggests that we extract and use this information, responding more favorably to those who sacrifice more even if they provide us with less. The magnitude of their trade-offs governs our social responses to them-including partner choice, giving, and anger. This implies that people have well-designed cognitive mechanisms for estimating the weight someone else assigns to their welfare, even when the amounts at stake vary and the information is noisy or sparse. We tested this hypothesis in two studies (N=200; US samples) by asking participants to observe a partner make two trade-offs, and then predict the partner's decisions in other trials. Their predictions were compared to those of a model that uses statistically optimal procedures, operationalized as a Bayesian ideal observer. As predicted, (i) the estimates people made from sparse evidence matched those of the ideal observer, and (ii) lower welfare trade-offs elicited more anger from participants, even when their total payoffs were held constant. These results support the view that people efficiently update their representations of how much others value them. They also provide the most direct test to date of a key assumption of the recalibrational theory of anger: that anger is triggered by cues of low valuation, not by the infliction of costs.

An Asymmetric Effect: Physical and Simulated Confederate's Mere Presence Induce a Preference for Deontological Over Utilitarian Judgment

People may behave differently in a shared physical context due to the mere presence of others. The study examined whether individual moral judgments were subject to the confederate's presence. Experiment 1 supported the hypothesis that the confederate's presence, relative to the control group, increased deontological judgment, disapproving of sacrificing a person's lifetime or interest for preserving the greater good of others. Experiment 2 investigated whether the results extend to mental space. The result revealed that simulating a positive interaction with the confederate significantly increased the preference for deontological judgments relative to the control group. However, the effect disappeared if the participants were required to simulate only the person from the scenario that did not include any additional background contexts. These results demonstrated that the confederate's physical presence and simulated confederate's presence always preferred deontological judgments over utilitarian judgments. The findings suggested that the asymmetric moral effect occurred in the physical realm and mental space.

Role polarization and its effects in the spatial ultimatum game

Human society is believed to be becoming increasingly polarized, yet it remains unclear how role polarization influences the evolution of fairness. In addition, little is known about role adaptation, despite the fact that altering the roles of players can often change the outcome of the ultimatum game. Unlike earlier static, random, symmetric role assignment, here I suggest a succeed-reinforce-fail-slacken role adaptation rule that encourages successful proposers in the present round to propose again in the next round and vice versa. The results demonstrate that this simple rule can tip the scales in favor of fair strategies when it comes to the proposer advantage, and therein lies the key to promoting fairness. Depending on its pace, notably, role adaptation can direct the system to equilibrium states that bear variable degrees of role polarization, with two consequences incidentally. Not only does it favor fairness, it also fosters empathy. Noise associated with role adaptation often reduces role polarization and thus has a negative impact on fairness and empathy. The comparison of experiments with various networks validates the substantial resilience of role polarization to structural changes. These findings add to the evidence for role polarization and highlight the centrality of role adaptation in the evolution of fairness.

Should I stay or should I go? Three-year-olds' reactions to appropriate motives to interrupt a joint activity

Understanding when it is acceptable to interrupt a joint activity is an important part of understanding what cooperation entails. Philosophical analyses have suggested that we should release our partner from a joint activity anytime the activity conflicts with fulfilling a moral obligation. To probe young children's understanding of this aspect, we investigated whether 3-year-old children (N = 60) are sensitive to the legitimacy of motives (selfish condition vs. moral condition) leading agents to intentionally interrupt their joint activity. We measured whether children protested or released their partner by scoring their reactions. Our results indicate that children did not manifest different reactions when the motive behind their partner leaving was moral than when the motive was selfish. However, our data showed a stable pattern: regardless of the partner's motives, some 3-year-olds take initiatives to release their partners from joint activity, suggesting that measuring release is a valuable tool for investigating joint action.

Helpers or halos: examining the evaluative mechanisms underlying selective prosociality

This research examines the proximate evaluative mechanisms underlying prosocial partner choice-based reciprocity. Across four studies we presented 855 university undergraduates (online for course credit) and 76 4- to 6-year-olds (offline at a university laboratory) with vignettes describing prosocial, social and non-social characters, and asked participants about their person preferences in prosocial, social and general contexts. Adults demonstrated sophisticated appraisals, coordinating between relevant trait and contextual cues to make selections. Adults were particularly attentive to prosocial cues in costly conditions, suggesting that they were using dispositional attributions to make their selections. By contrast, children were largely unable to integrate trait and contextual cues in determining their partner preferences, instead displaying valenced preferences for non-social cues, suggesting the use of affective tagging. Together, these studies demonstrate that the mechanisms underlying prosocial, partner choice-based reciprocity are not early emerging and stable but show considerable development over the lifespan.

Characterizing the trophy hunting debate on Twitter

Social media is an arena of debate for contentious political and social topics. One conservation topic debated online is the acceptability of trophy hunting, a debate that has implications for national and international policy. We used a mixed-methods approach (grounded theory and quantitative clustering) to identify themes in the trophy hunting debate on Twitter. We examined commonly co-occurring categories that describe people's stances on trophy hunting. We identified 12 categories and 4 preliminary archetypes opposing trophy hunting-activism, scientific, condemning, and objecting-whose opposition derived from different moral reasoning. Few tweets (22) in our sample of 500 supported trophy hunting, whereas 350 opposed it. The debate was hostile; 7% of tweets in our sample were categorized as abusive. Online debates can be unproductive, and our findings may be important for stakeholders wishing to effectively engage in the trophy hunting debate on Twitter. More generally, we contend that because social media is increasingly influential, it is important to formally contextualize public responses to contentious conservation topics in order to aid communication of conservation evidence and to integrate diverse public perspectives in conservation practice.

Evolutionary dynamics under partner preferences

The fact that people often have preference rankings for their partners is a distinctive aspect of human behavior. Little is known, however, about how this talent as a powerful force shapes human behavioral traits, including those which should not have been favored by selection, such as cooperation in social dilemma situations. Here we propose a dynamic model in which network-structured individuals can switch their interaction partners within neighborhoods based on their preferences. For the partner switching, we propose two interruption regimes: dictatorial regime and negotiating regime. In the dictatorial regime, focal individuals are able to suspend interactions out of preferences unilaterally. In the negotiating regime, either focal individuals or the associated partners agree to suspend, then these interactions can be successfully suspended. We investigate the evolution of cooperation under both preference-driven partner switching regimes in the context of both the weakened variant of the donation game and the standard one. Specifically, we theoretically approximate the critical conditions for cooperation to be favored by weak selection in the weakened donation game where cooperators bear a unit cost to provide a benefit for each active neighbor and simulate the evolutionary dynamics of cooperation in the standard donation game to test the robustness of the analytical results. Under dictatorial regime, selection of cooperation becomes harder when individuals have preferences for either cooperator or defector partners, implying that the expulsion of defectors by cooperators is overwhelmed by the chasing of defectors towards cooperators. Under negotiating regime, both preferences for cooperator and defector partners can significantly favor the evolution of cooperation, yet underlying mechanisms differ greatly. For preferences over cooperator partners, cooperator-cooperator interaction relationships are reinforced and the associated mutual reciprocity can resist and assimilate defectors. For preferences over defector partners, defector-defector interaction relationships are anchored, weakening defectors' exploitation over cooperators. Cooperators are thus offered much time space to interact among cospecies and spread. Our work may help better understand the critical role of preference-based adaptive partner switching in promoting the evolution of cooperation.

The computational society

How do individual human minds create languages, legal systems, scientific theories, and technologies? From a cognitive science viewpoint, such collective phenomena may be considered a type of distributed computation in which human minds together solve computational problems beyond any individual. This viewpoint may also shift our perspective on individual minds.

Political conspiracy theories as tools for mobilization and signaling

Political conspiracist communities emerge and bind around hard-to-falsify narratives about political opponents or elites convening to secretly exploit the public in contexts of perceived political conflict. While the narratives appear descriptive, we propose that their content as well as the cognitive systems regulating their endorsement and dissemination may have co-evolved, at least in part, to reach coalitional goals: To drive allies' attention to the social threat to increase their commitment and coordination for collective action, and to signal devotion to gain within-group status. Those evolutionary social functions may be best fulfilled if individuals endorse the conspiratorial narrative sincerely.

Interaction between games give rise to the evolution of moral norms of cooperation

In many biological populations, such as human groups, individuals face a complex strategic setting, where they need to make strategic decisions over a diverse set of issues and their behavior in one strategic context can affect their decisions in another. This raises the question of how the interaction between different strategic contexts affects individuals’ strategic choices and social norms? To address this question, I introduce a framework where individuals play two games with different structures and decide upon their strategy in a second game based on their knowledge of their opponent’s strategy in the first game. I consider both multistage games, where the same opponents play the two games consecutively, and reputation-based model, where individuals play their two games with different opponents but receive information about their opponent’s strategy. By considering a case where the first game is a social dilemma, I show that when the second game is a coordination or anti-coordination game, the Nash equilibrium of the coupled game can be decomposed into two classes, a defective equilibrium which is composed of two simple equilibrium of the two games, and a cooperative equilibrium, in which coupling between the two games emerge and sustain cooperation in the social dilemma. For the existence of the cooperative equilibrium, the cost of cooperation should be smaller than a value determined by the structure of the second game. Investigation of the evolutionary dynamics shows that a cooperative fixed point exists when the second game belongs to coordination or anti-coordination class in a mixed population. However, the basin of attraction of the cooperative fixed point is much smaller for the coordination class, and this fixed point disappears in a structured population. When the second game belongs to the anti-coordination class, the system possesses a spontaneous symmetry-breaking phase transition above which the symmetry between cooperation and defection breaks. A set of cooperation supporting moral norms emerges according to which cooperation stands out as a valuable trait. Notably, the moral system also brings a more efficient allocation of resources in the second game. This observation suggests a moral system has two different roles: Promotion of cooperation, which is against individuals’ self-interest but beneficial for the population, and promotion of organization and order, which is at both the population’s and the individual’s self-interest. Interestingly, the latter acts like a Trojan horse: Once established out of individuals’ self-interest, it brings the former with itself. Importantly, the fact that the evolution of moral norms depends only on the cost of cooperation and is independent of the benefit of cooperation implies that moral norms can be harmful and incur a pure collective cost, yet they are just as effective in promoting order and organization. Finally, the model predicts that recognition noise can have a surprisingly positive effect on the evolution of moral norms and facilitates cooperation in the Snow Drift game in structured populations.

How do moral norms spontaneously evolve in the presence of selfish incentives? An answer to this question is provided by the observation that moral systems have two distinct functions: Besides encouraging self-sacrificing cooperation, they also bring organization and order into the societies. In contrast to the former, which is costly for the individuals but beneficial for the group, the latter is beneficial for both the group and the individuals. A simple evolutionary model suggests this latter aspect is what makes a moral system evolve based on the individuals’ self-interest. However, a moral system behaves like a Trojan horse: Once established out of the individuals’ self-interest to promote order and organization, it also brings self-sacrificing cooperation.

Moral disciplining: The cognitive and evolutionary foundations of puritanical morality

Why do many societies moralize apparently harmless pleasures, such as lust, gluttony, alcohol, drugs, and even music and dance? Why do they erect temperance, asceticism, sobriety, modesty, and piety as cardinal moral virtues? According to existing theories, this puritanical morality cannot be reduced to concerns for harm and fairness: It must emerge from cognitive systems that did not evolve for cooperation (e.g., disgust-based "purity" concerns). Here, we argue that, despite appearances, puritanical morality is no exception to the cooperative function of moral cognition. It emerges in response to a key feature of cooperation, namely that cooperation is (ultimately) a long-term strategy, requiring (proximately) the self-control of appetites for immediate gratification. Puritanical moralizations condemn behaviors which, although inherently harmless, are perceived as indirectly facilitating uncooperative behaviors, by impairing the self-control required to refrain from cheating. Drinking, drugs, immodest clothing, and unruly music and dance are condemned as stimulating short-term impulses, thus facilitating uncooperative behaviors (e.g., violence, adultery, free-riding). Overindulgence in harmless bodily pleasures (e.g., masturbation, gluttony) is perceived as making people slave to their urges, thus altering abilities to resist future antisocial temptations. Daily self-discipline, ascetic temperance, and pious ritual observance are perceived as cultivating the self-control required to honor prosocial obligations. We review psychological, historical, and ethnographic evidence supporting this account. We use this theory to explain the fall of puritanism in western, educated, industrialized, rich, and democratic (WEIRD) societies, and discuss the cultural evolution of puritanical norms. Explaining puritanical norms does not require adding mechanisms unrelated to cooperation in our models of the moral mind.

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.

High achievers, Schadenfreude and Gluckschmerz in New Zealanders and Chinese

The willingness to support (or denigrate) high-profile individuals online was examined across cultures using the Tall Poppy Scale. A sample of 106 Chinese and 164 New Zealand Europeans answered an online questionnaire addressing their preference for high achievers to be rewarded or fail. Participants were asked whether they would vote to support reality TV contestants, and offered further information (about success or failure) on a debrief page. The Favour Reward scale predicted willingness to vote and support others. The Favour Fall subscale tended to predict time spent viewing achievement-related information on a debrief page. The Chinese sample did not prefer reward of high achievers, instead favoring their fall, but spent less time per click on the debrief page, suggesting they disliked recognizing individual achievement.

Is Distributional Justice Equivalent to Prosocial Sharing in Children’s Cognition?

Distribution and sharing are social preference behaviors supported and shaped by selection pressures, which express individuals’ concern for the welfare of others. Distributive behavior results in distributive justice, which is at the core of moral justice. Sharing is a feature of the prosocial realm. The connotations of distribution and sharing are different, so the principles, research paradigms, and social functions of the two are also different. Three potential causes of confusion between the two in the current research on distribution and sharing are discussed. First, they share common factors in terms of individual cognition, situation, and social factors. Second, although they are conceptually different, prosocial sharing and distribution fairness sensitivity are mutually predictive in individual infants. Similarly, neural differences in preschoolers’ perception of distribution fairness predict their subsequent sharing generosity. Finally, similar activation regions are relevant to distribution and sharing situations that need behavioral control on a neural basis.

Retrospective Self-Reported Childhood Experiences in Enriched Environments Uniquely Predict Prosocial Behavior and Personality Traits in Adulthood

What features of people's childhood environments go on to shape their prosocial behavior during adulthood? Past studies linking childhood environment to adult prosocial behavior have focused primarily on adverse features, thereby neglecting the possible influence of exposure to enriched environments (e.g., access to material resources, experiences with rich cooperative relationships, and interactions with morally exemplary role models). Here, we expand the investigation of childhood environmental quality to include consideration of enriching childhood experiences and their relation to adult prosociality. In two cross-sectional studies, we found promising evidence that enriched childhood environments are associated with adult moral behavior. In study 1 (N = 1,084 MTurk workers), we adapted an existing measure of enriched childhood environmental quality for retrospective recall of childhood experiences and found that subjects' recollections of their enriched childhood experiences are distinct from their recollections of adverse childhood experiences. In Study 2 (N = 2,208 MTurk workers), we found that a formative composite of subjects' recollections of enriched childhood experiences is positively associated with a variety of morally relevant traits in adulthood, including agreeableness, honesty-humility, altruism, endorsement of the principle of care, empathic responding to the plights of needy others, and charitable donations in an experimental setting, and that these associations held after controlling for childhood environmental adversity, childhood socioeconomic status, sex, and age. We also found evidence suggesting that some, but not all, of the relationship between enrichment and adult prosociality can be explained by a shared genetic correlation. We include a new seven-item measure as an appendix.

Hadza hunter-gatherers with greater exposure to other cultures share more with generous campmates

Humans are motivated to compete for access to valuable social partners, which is a function of their willingness to share and ability to generate resources. However, relative preferences for each trait should be responsive to socioecological conditions. Here, we test the flexibility of partner choice psychology among Hadza hunter-gatherers of Tanzania. Ninety-two Hadza ranked their campmates on generosity and foraging ability and then shared resources with those campmates. We found Hadza with greater exposure to other cultures shared more with campmates ranked higher on generosity, whereas Hadza with lower exposure showed a smaller preference for sharing with generous campmates. This moderating effect was specific to generosity-regardless of exposure, Hadza showed only a small preference for sharing with better foragers. We argue this difference in preferences is due to high exposure Hadza having more experience cooperating with others in the absence of strong norms of sharing, and thus are exposed to greater variance in willingness to cooperate among potential partners increasing the benefits of choosing partners based on generosity. As such, participants place a greater emphasis on choosing more generous partners, highlighting the flexibility of partner preferences.

Free to choose: Mutualist motives for partner choice, proportional division, punishment, and help

Mutualism–the disposition to cooperate in ways that benefit both actor and recipient–has been proposed as a key construct in the evolution of cooperation, with distinct adaptations for 1) partner choice, 2) division, 3) punishment, and 4) helping. However, no psychological validation of this 4-fold psychological structure exists, and no measure of the trait is available. To fill this need, in two pre-registered studies (total N = 902), we: (A) Develop and administer items assessing each of the four mutualist adaptations; (B) Show good fit to the predicted four factor model; (C) Demonstrate reliability and stability across time; (D) Evidence discriminant validity from existing constructs, including compassion and utilitarianism; (E) Establish external validity by predicting proportional choices in catch division, opposition to partner coercion, and reduced support for redistribution; and (F) Replicate each of these findings. Jointly, these results support the validity of mutualism, including a motive to maintain the freedom to choose, and provide reliable scales for use in integrating, further developing, and applying mutualism.

Motivations to reciprocate cooperation and punish defection are calibrated by estimates of how easily others can switch partners

Evolutionary models of dyadic cooperation demonstrate that selection favors different strategies for reciprocity depending on opportunities to choose alternative partners. We propose that selection has favored mechanisms that estimate the extent to which others can switch partners and calibrate motivations to reciprocate and punish accordingly. These estimates should reflect default assumptions about relational mobility: the probability that individuals in one’s social world will have the opportunity to form relationships with new partners. This prior probability can be updated by cues present in the immediate situation one is facing. The resulting estimate of a partner’s outside options should serve as input to motivational systems regulating reciprocity: Higher estimates should down-regulate the use of sanctions to prevent defection by a current partner, and up-regulate efforts to attract better cooperative partners by curating one’s own reputation and monitoring that of others. We tested this hypothesis using a Trust Game with Punishment (TGP), which provides continuous measures of reciprocity, defection, and punishment in response to defection. We measured each participant’s perception of relational mobility in their real-world social ecology and experimentally varied a cue to partner switching. Moreover, the study was conducted in the US (n = 519) and Japan (n = 520): societies that are high versus low in relational mobility. Across conditions and societies, higher perceptions of relational mobility were associated with increased reciprocity and decreased punishment: i.e., those who thought that others have many opportunities to find new partners reciprocated more and punished less. The situational cue to partner switching was detected, but relational mobility in one’s real social world regulated motivations to reciprocate and punish, even in the experimental setting. The current research provides evidence that motivational systems are designed to estimate varying degrees of partner choice in one’s social ecology and regulate reciprocal behaviors accordingly.

Computational ethics

Technological advances are enabling roles for machines that present novel ethical challenges. The study of 'AI ethics' has emerged to confront these challenges, and connects perspectives from philosophy, computer science, law, and economics. Less represented in these interdisciplinary efforts is the perspective of cognitive science. We propose a framework - computational ethics - that specifies how the ethical challenges of AI can be partially addressed by incorporating the study of human moral decision-making. The driver of this framework is a computational version of reflective equilibrium (RE), an approach that seeks coherence between considered judgments and governing principles. The framework has two goals: (i) to inform the engineering of ethical AI systems, and (ii) to characterize human moral judgment and decision-making in computational terms. Working jointly towards these two goals will create the opportunity to integrate diverse research questions, bring together multiple academic communities, uncover new interdisciplinary research topics, and shed light on centuries-old philosophical questions.

How fairness and dominance guide young children's bargaining decisions

Reaching agreements in conflicts is an important developmental challenge. Here, German 5-year-olds (N = 284, 49% female, mostly White, mixed socioeconomic backgrounds; data collection: June 2016-November 2017) faced repeated face-to-face bargaining problems in which they chose between fair and unfair reward divisions. Across three studies, children mostly settled on fair divisions. However, dominant children tended to benefit more from bargaining outcomes (in Study 1 and 2 but not Study 3) and children mostly failed to use leverage to enforce fairness. Communication analyses revealed that children giving orders to their partner had a bargaining advantage and that children provided and responded to fairness reasons. These findings indicate that fairness concerns and dominance are both key factors that shape young children's bargaining decisions.

Morality, Risk-Taking and Psychopathic Tendencies: An Empirical Study

Research in empirical moral psychology has consistently found negative correlations between morality and both risk-taking, as well as psychopathic tendencies. However, prior research did not sufficiently explore intervening or moderating factors. Additionally, prior measures of moral preference (e.g., sacrificial dilemmas) have a pronounced lack of ecological validity. This study seeks to address these two gaps in the literature. First, this study used Preference for Precepts Implied in Moral Theories (PPIMT), which offers a novel, more nuanced and ecologically valid measure of moral judgment. Second, the current study examined if risk taking moderates the relationships between psychopathic tendencies and moral judgment. Results indicated that models which incorporated risk-taking as a moderator between psychopathic tendencies and moral judgment were a better fit to the data than those that incorporated psychopathic tendencies and risk-taking as exogenous variables, suggesting that the association between psychopathic tendencies and moral judgment is influenced by level of risk-taking. Therefore, future research investigating linkages between psychopathic tendencies and moral precepts may do well to incorporate risk-taking and risky behaviors to further strengthen the understanding of moral judgment in these individuals.

Why and How Did Narrative Fictions Evolve? Fictions as Entertainment Technologies

Narrative fictions have surely become the single most widespread source of entertainment in the world. In their free time, humans read novels and comics, watch movies and TV series, and play video games: they consume stories that they know to be false. Such behaviors are expanding at lightning speed in modern societies. Yet, the question of the origin of fictions has been an evolutionary puzzle for decades: Are fictions biological adaptations, or the by-products of cognitive mechanisms that evolved for another purpose? The absence of any consensus in cognitive science has made it difficult to explain how narrative fictions evolve culturally. We argue that current conflicting hypotheses are partly wrong, and partly right: narrative fictions are by-products of the human mind, because they obviously co-opt some pre-existing cognitive preferences and mechanisms, such as our interest for social information, and our abilities to do mindreading and to imagine counterfactuals. But humans reap some fitness benefits from producing and consuming such appealing cultural items, making fictions adaptive. To reconcile these two views, we put forward the hypothesis that narrative fictions are best seen as entertainment technologies that is, as items crafted by some people for the proximate goal to grab the attention of other people, and with the ultimate goal to fulfill other evolutionary-relevant functions that become easier once other people's attention is caught. This hypothesis explains why fictions are filled with exaggerated and entertaining stimuli, why they fit so well the changing preferences of the audience they target, and why producers constantly make their fictions more attractive as time goes by, in a cumulative manner.

Expression unleashed: The evolutionary and cognitive foundations of human communication

Human expression is open-ended, versatile, and diverse, ranging from ordinary language use to painting, from exaggerated displays of affection to micro-movements that aid coordination. Here we present and defend the claim that this expressive diversity is united by an interrelated suite of cognitive capacities, the evolved functions of which are the expression and recognition of informative intentions. We describe how evolutionary dynamics normally leash communication to narrow domains of statistical mutual benefit, and how expression is unleashed in humans. The relevant cognitive capacities are cognitive adaptations to living in a partner choice social ecology; and they are, correspondingly, part of the ordinarily developing human cognitive phenotype, emerging early and reliably in ontogeny. In other words, we identify distinctive features of our species' social ecology to explain how and why humans, and only humans, evolved the cognitive capacities that, in turn, lead to massive diversity and open-endedness in means and modes of expression. Language use is but one of these modes of expression, albeit one of manifestly high importance. We make cross-species comparisons, describe how the relevant cognitive capacities can evolve in a gradual manner, and survey how unleashed expression facilitates not only language use, but also novel behaviour in many other domains too, focusing on the examples of joint action, teaching, punishment, and art, all of which are ubiquitous in human societies but relatively rare in other species. Much of this diversity derives from graded aspects of human expression, which can be used to satisfy informative intentions in creative and new ways. We aim to help reorient cognitive pragmatics, as a phenomenon that is not a supplement to linguistic communication and on the periphery of language science, but rather the foundation of the many of the most distinctive features of human behaviour, society, and culture.