The norm-dependent effect of watching eyes on donation

Although many previous studies have shown that eye-like images promote generosity, the mechanism of this “watching eyes effect” remains unclear. One possible cause is the concern for a good reputation as a generous person, while the other is the concerns for a bad reputation as a norm violator. To elucidate which of these two concerns is the main influencer, the present study conducted a laboratory experiment that investigated whether the watching eyes effect changed depending on social norms. If the concern for a good reputation leads to the effect, prosocial behavior would be more likely in the presence of watching eyes, regardless of the social norms involved. However, if the concern for avoiding a bad reputation as a norm violator leads to the effect, watching eyes promote prosocial behavior only in the existence of prosocial norms. In the original study, participants were asked to make a charitable donation under conditions in which eye-like images either were or were not present. In addition to the eye-like images, we manipulated prosocial norms by informing each participant of either high or low mean donation amounts given by previous participants. We found that watching eyes promoted donations only when a prosocial norm existed. This supports the idea that the watching eyes effect is caused by a concern for avoiding a bad reputation from violating norms. However, in a replication study, we were unable to replicate the original results; watching eyes did not promote generosity regardless of the norm. Taken together, we discussed the moderation effect of norms and the possibility of other moderators.     

Task Design Influences Prosociality in Captive Chimpanzees (Pan troglodytes)

Chimpanzees confer benefits on group members, both in the wild and in captive populations. Experimental studies of how animals allocate resources can provide useful insights about the motivations underlying prosocial behavior, and understanding the relationship between task design and prosocial behavior provides an important foundation for future research exploring these animals'' social preferences. A number of studies have been designed to assess chimpanzees'' preferences for outcomes that benefit others (prosocial preferences), but these studies vary greatly in both the results obtained and the methods used, and in most cases employ procedures that reduce critical features of naturalistic social interactions, such as partner choice. The focus of the current study is on understanding the link between experimental methodology and prosocial behavior in captive chimpanzees, rather than on describing these animals'' social motivations themselves. We introduce a task design that avoids isolating subjects and allows them to freely decide whether to participate in the experiment. We explore key elements of the methods utilized in previous experiments in an effort to evaluate two possibilities that have been offered to explain why different experimental designs produce different results: (a) chimpanzees are less likely to deliver food to others when they obtain food for themselves, and (b) evidence of prosociality may be obscured by more “complex” experimental apparatuses (e.g., those including more components or alternative choices). Our results suggest that the complexity of laboratory tasks may generate observed variation in prosocial behavior in laboratory experiments, and highlights the need for more naturalistic research designs while also providing one example of such a paradigm.     

Give What You Get: Capuchin Monkeys (Cebus apella) and 4-Year-Old Children Pay Forward Positive and Negative Outcomes to Conspecifics

The breadth of human generosity is unparalleled in the natural world, and much research has explored the mechanisms underlying and motivating human prosocial behavior. Recent work has focused on the spread of prosocial behavior within groups through paying-it-forward, a case of human prosociality in which a recipient of generosity pays a good deed forward to a third individual, rather than back to the original source of generosity. While research shows that human adults do indeed pay forward generosity, little is known about the origins of this behavior. Here, we show that both capuchin monkeys (Cebus apella) and 4-year-old children pay forward positive and negative outcomes in an identical testing paradigm. These results suggest that a cognitively simple mechanism present early in phylogeny and ontogeny leads to paying forward positive, as well as negative, outcomes.     

Do marmosets care to share? Oxytocin treatment reduces prosocial behavior toward strangers

Cooperatively-breeding and socially-monogamous primates, like marmosets and humans, exhibit high levels of social tolerance and prosociality toward others. Oxytocin (OXT) generally facilitates prosocial behavior, but there is growing recognition that OXT modulation of prosocial behavior is shaped by the context of social interactions and by other motivational states such as arousal or anxiety. To determine whether prosociality varies based on social context, we evaluated whether marmoset donors (Callithrix penicillata) preferentially rewarded pairmates versus opposite-sex strangers in a prosocial food-sharing task. To examine potential links among OXT, stress systems, and prosociality, we evaluated whether pretrial cortisol levels in marmosets altered the impact of OXT on prosocial responses. Marmosets exhibited spontaneous prosociality toward others, but they did so preferentially toward strangers compared to their pairmates. When donor marmosets were treated with marmoset-specific Pro⁸-OXT, they exhibited reduced prosociality toward strangers compared to marmosets treated with saline or consensus-mammalian Leu⁸-OXT. When pretrial cortisol levels were lower, marmosets exhibited higher prosociality toward strangers. These findings demonstrate that while marmosets show spontaneous prosocial responses toward others, they do so preferentially toward opposite-sex strangers. Cooperative breeding may be associated with the expression of prosociality, but the existence of a pair-bond between marmoset partners appears to be neither necessary nor sufficient for the expression of spontaneous prosocial responses. Furthermore, high prosociality toward strangers is significantly reduced in marmosets treated with Pro⁸-OXT, suggesting that OXT does not universally enhance prosociality, but, rather OXT modulation of prosocial behavior varies depending on social context.     

Everybody Else Is Doing It: Exploring Social Transmission of Lying Behavior

Lying is a common occurrence in social interactions, but what predicts whether an individual will tell a lie? While previous studies have focused on personality factors, here we asked whether lying tendencies might be transmitted through social networks. Using an international sample of 1,687 socially connected pairs, we investigated whether lying tendencies were related in socially connected individuals, and tested two moderators of observed relationships. Participants recruited through a massive open online course reported how likely they would be to engage in specific lies; a friend or relative responded to the same scenarios independently. We classified lies according to their beneficiary (antisocial vs. prosocial lies), and their directness (lies of commission vs. omission), resulting in four unique lying categories. Regression analyses showed that antisocial commission, antisocial omission, and prosocial commission lying tendencies were all uniquely related in connected pairs, even when the analyses were limited to pairs that were not biologically related. For antisocial lies of commission, these relationships were strongest, and were moderated by amount of time spent together. Randomly paired individuals from the same countries were also related in their antisocial commission lying tendencies, signifying country-level norms. Our results indicate that a person''s lying tendencies can be predicted by the lying tendencies of his or her friends and family members.     

Rewarding the good and punishing the bad: The role of karma and afterlife beliefs in shaping moral norms

Moralizing religions encourage people to anticipate supernatural punishments for violating moral norms, even in anonymous interactions. This is thought to be one way large-scale societies have solved cooperative dilemmas. Previous research has overwhelmingly focused on the effects of moralizing gods, and has yet to thoroughly examine other religious moralizing systems, such as karma, to which more than a billion people subscribe worldwide. In two pre-registered studies conducted with Chinese Singaporeans, we compared the moralizing effects of karma and afterlife beliefs of Buddhists, Taoists, Christians, and the non-religious. In Study 1 (N = 582), we found that Buddhists and Taoists (karmic religions) judge individual actions as having greater consequences in this life and the next, compared to Christians. Pointing to the specific role of karma beliefs in these judgements, these effects were replicated in comparisons of participants from the non-karmic religions/groups (Christian and non-religious) who did or did not endorse karma belief. Study 2 (N = 830) exploited religious syncretism in this population by reminding participants about either moral afterlife beliefs (reincarnation or heaven/hell), ancestor veneration beliefs, or neither, before assessing norms of generosity in a series of hypothetical dictator games. When reminded of their ancestor veneration beliefs, Buddhists and Taoists (but not Christians) endorsed parochial prosocial norms, expressing willingness to give more to their family and religious group than did those in the control condition. Moral afterlife beliefs increased generosity to strangers for all groups. Taken together, these results provide evidence that different religious beliefs can foster and maintain different prosocial and cooperative norms.     

Fourteen-month-old infants use interpersonal synchrony as a cue to direct helpfulness

Musical behaviours such as dancing, singing and music production, which require the ability to entrain to a rhythmic beat, encourage high levels of interpersonal coordination. Such coordination has been associated with increased group cohesion and social bonding between group members. Previously, we demonstrated that this association influences even the social behaviour of 14-month-old infants. Infants were significantly more likely to display helpfulness towards an adult experimenter following synchronous bouncing compared with asynchronous bouncing to music. The present experiment was designed to determine whether interpersonal synchrony acts as a cue for 14-month-olds to direct their prosocial behaviours to specific individuals with whom they have experienced synchronous movement, or whether it acts as a social prime, increasing prosocial behaviour in general. Consistent with the previous results, infants were significantly more likely to help an experimenter following synchronous versus asynchronous movement with this person. Furthermore, this manipulation did not affect infant''s behaviour towards a neutral stranger, who was not involved in any movement experience. This indicates that synchronous bouncing acts as a social cue for directing prosociality. These results have implications for how musical engagement and rhythmic synchrony affect social behaviour very early in development.     

Individual heterogeneity and costly punishment: a volunteer's dilemma

Social control and the enforcement of social norms glue a society together. It has been shown theoretically and empirically that informal punishment of wrongdoers fosters cooperation in human groups. Most of this research has focused on voluntary and uncoordinated punishment carried out by individual group members. However, as punishment is costly, it is an open question as to why humans engage in the punishment of wrongdoers even in one-time-only encounters. While evolved punitive preferences have been advocated as proximate explanations for such behaviour, the strategic nature of the punishment situation has remained underexplored. It has been suggested to conceive of the punishment situation as a volunteer''s dilemma (VOD), where only one individual''s action is necessary and sufficient to punish the wrongdoer. Here, we show experimentally that implementing the punishment situation as a VOD sustains cooperation in an environment where punishers and non-punishers coexist. Moreover, we show that punishment-cost heterogeneity allows individuals to tacitly agree on only the strongest group member carrying out the punishment, thereby increasing the effectiveness and efficiency of social norm enforcement. Our results corroborate that costly peer punishment can be explained without assuming punitive preferences and show that centralized sanctioning institutions can emerge from arbitrary individual differences.     

Benefiting friends or dominants: prosocial choices mainly depend on rank position in long-tailed macaques (<Emphasis Type="Italic">Macaca fascicularis</Emphasis>)

Long-term observational studies in a number of animal species suggest that exchange patterns of social acts depend on long-term emotional bonds. Therefore, it is expected that the frequency of prosocial behavior will depend on the strength of such a bond. In this study we tested whether variation in relationship quality among unrelated individuals, i.e., “friends” and “nonfriends,” is predictive of the prosocial behavior of long-tailed macaques in two experiments. First, we related relationship quality to prosociality in a dyadic prosociality test, and second, we gave subjects the choice to give to either a friend or a nonfriend in a triadic choice test. We show that prosocial behavior of long-tailed macaques in the dyadic test is not related to relationship quality. When given the choice to give to either a friend or a nonfriend in the triadic test, there is a minor indication that long-tailed macaques show a preference to give to their friends, yet this indication is neither significant nor consistent. In contrast, subordinate long-tailed macaques make a more “competitive” choice and avoid giving to the individual closest in rank. Therefore, in the short-term situation of experimental tests, prosocial behavior of long-tailed macaques seems unaffected by the relationship quality of the dyad/triad tested, and the relative dominance position of these dyads/triads seems to have a much stronger effect on their prosocial behavior.     

Geometry for a selfish foraging group: a genetic algorithm approach

The advantages of group living are not shared equally among all group members and these advantages may depend on the spatial position occupied by a forager within the group. For instance, it is thought that socially dominant individuals prefer the predator-safe central position of groups forcing subordinates to the periphery. Uneven spread of benefits among group members can occur when some animals (the scroungers) parasitically exploit the food findings of other foragers (the producers). Here we focus on how playing producer or scrounger affects an individual''s spatial position within a group. We model the movement of foraging animals playing scrounger or producer using a spatially explicit simulation and use a genetic algorithm to establish movement rules. We find that groups containing producers and scroungers are more compact compared to an equivalent group of producers only. Furthermore, the position occupied by strategies varies: scroungers are mainly found in central positions, while producers in the periphery, suggesting that the best position for strategies differs. Dominants, therefore, should prefer movement rules which lead to central positions because of the positional benefits provided to the scrounger strategy they use. Moreover, position within a group will introduce an asymmetry among otherwise phenotypically symmetric individuals.     

Culture and Disability Behavior

A substantial amount of literature suggests that illness behavior in the United States is a product of a patient''s core culture; equally credible findings do not support this contention. Most students and graduates in the health care professions believe that illness and disability behavior are affected by a patient''s culture, but they are hard put to find convincing examples of that relationship. In experience with medical students studying the social and cultural bases of illness behavior, with patients who are disabled and with persons who claim disability in the absence of physical disease or disabling psychopathology, I observed no deviant disability behavior that was typical for the members of any cultural group, and no behavior was displayed by the members of one cultural group that was not seen in members of other cultural groups. No cultural stereotypes were upheld. I did find evidence that disability behavior is influenced by personality factors, social situations and the gains derived from the disability status. Evolving concepts of “entitlement,” which are closely related to socioeconomic status, also have a significant influence. The impact of feedback from others in a person''s many social and medical subcultures is a more crucial determinant of illness and disability behavior, except in those for whom illness and disability behavior is determined by the limitations imposed by the disease or by a personality structure resistant to cultural expectations and social feedback.     

The Importance of Demonstratively Restoring Order

Contrary to what is often assumed, order is not the strongest context for encouraging normative behavior. The strongest context effect on normative behavior comes from cues that clearly convey other people’s respect for norms. Ironically, this show of respect necessitates some contrasting disrespect that is being restored. Using civic virtues (such as helping behavior) as a prototype of normative behavior, the three field experiments described in this paper reveal the impact of normative cues on civic virtues. Results show that the strongest effect on making people follow prosocial norms in public places emanates from seeing order being restored, rather than just order being present. The robust and surprisingly large effects show that observing other people’s respect for one particular norm (as evidenced in their restoring physical order) makes it more likely that the onlooker follows other norms as well. This implies that prosocial behavior has the highest chance of spreading when people observe order being restored. There are clear policy implications: create low cost “normative respect cues” wherever it is desirable to increase conformity to norms.     

Affective Balance,Team Prosocial Efficacy and Team Trust: A Multilevel Analysis of Prosocial Behavior in Small Groups

Little research has focused on how individual- and team-level characteristics jointly influence, via interaction, how prosocially individuals behave in teams and few studies have considered the potential influence of team context on prosocial behavior. Using a multilevel perspective, we examined the relationships between individual (affective balance) and group (team prosocial efficacy and team trust) level variables and prosocial behavior towards team members. The participants were 123 students nested in 45 small teams. A series of multilevel random models was estimated using hierarchical linear and nonlinear modeling. Individuals were more likely to behave prosocially towards in-group members when they were feeling good. Furthermore, the relationship between positive affective balance and prosocial behavior was stronger in teams with higher team prosocial efficacy levels as well as in teams with higher team trust levels. Finally, the relevance of team trust had a stronger influence on behavior than team prosocial efficacy.     

The role of mesotocin on social bonding in pinyon jays

The neuropeptide oxytocin influences mammalian social bonding by facilitating the building and maintenance of parental, sexual, and same-sex social relationships. However, we do not know whether the function of the avian homologue mesotocin is evolutionarily conserved across birds. While it does influence avian prosocial behavior, mesotocin's role in avian social bonding remains unclear. Here, we investigated whether mesotocin regulates the formation and maintenance of same-sex social bonding in pinyon jays (Gymnorhinus cyanocephalus), a member of the crow family. We formed squads of four individually housed birds. In the first, “pair-formation” phase of the experiment, we repeatedly placed pairs of birds from within the squad together in a cage for short periods of time. Prior to entering the cage, we intranasally administered one of three hormone solutions to both members of the pair: mesotocin, oxytocin antagonist, or saline. Pairs received repeated sessions with administration of the same hormone. In the second, “pair-maintenance” phase of the experiment, all four members of the squad were placed together in a large cage, and no hormones were administered. For both phases, we measured the physical proximity between pairs as our proxy for social bonding. We found that, compared with saline, administering mesotocin or oxytocin antagonist did not result in different proximities in either the pair-formation or pair-maintenance phase of the experiment. Therefore, at the dosages and time frames used here, exogenously introduced mesotocin did not influence same-sex social bond formation or maintenance. Like oxytocin in mammals, mesotocin regulates avian prosocial behavior; however, unlike oxytocin, we do not have evidence that mesotocin regulates social bonds in birds.     

Attentiveness to eyes predicts generosity in a reputation-relevant context

Eyes play a vital role in human social interactions. In fact, some prior work indicates that simply the presence of eyes or eye-like stimuli increases people's prosocial behavior, arguably because the eyes serve as cues of being watched and thus elicit reputational concerns. The current study was designed to address two questions in this regard. First, we examined how salient the eyes are among the human features. Second, we asked whether individual differences in attentiveness to eyes (but not other human features such as ears or hands) are predictive of reputation-enhancing behavior. Using an eye-tracking paradigm, we found that participants looked longest to eyes compared to other human features. Critically, greater attentiveness to eyes correlated with greater generosity on a donation task, but only in a reputation-relevant context (i.e., when donations were public but not when they were anonymous). Attentiveness to other human features did not predict donation behavior. Eyes are thus an especially salient human feature, and attentiveness to eyes may signal individuals' concerns about their reputations.     

Altruism towards strangers in need: costly signaling in an industrial society

In the present study, the costly signaling theory (CST) is used to examine the effect of an offer of charity on social recognition. On behalf of a charitable organization, 186 students enrolled in 16 different courses were asked to offer support to unfamiliar persons in need. In accordance with our predictions, the results show that significantly more subjects are willing to give assistance if they make charity offers in the presence of their group members than when the offers are made in secret. In accordance with CST—but not with the prevailing explanations in social psychology—the likelihood of charity service was strongly influenced by the expected cost of altruistic behavior. Publicly demonstrated altruistic intentions yielded long-term benefits: Subjects who were willing to participate in a particular charity activity gained significantly higher sociometry scores (as a sign of social recognition) than did others. The cost of volunteerism correlated with social recognition in the case of a charity act judged as the most expensive (giving assistance to mentally retarded children), but not for the other categories of charity offer. Our results suggest that public generosity towards strangers as a costly signal may convey reliable information about subjects' personality traits, such as cooperativeness, but our data do not support the hypothesis that the signaling mechanism is related to sexual selection and mate choice.     

Why people punish defectors. Weak conformist transmission can stabilize costly enforcement of norms in cooperative dilemmas

In this paper, we present a cultural evolutionary model in which norms for cooperation and punishment are acquired via two cognitive mechanisms: (1) payoff-biased transmission-a tendency to copy the most successful individual; and (2) conformist transmission-a tendency to copy the most frequent behavior in the population. We first show that if a finite number of punishment stages is permitted (e.g. two stages of punishment occur if some individuals punish people who fail to punish non-cooperators), then an arbitrarily small amount of conformist transmission will stabilize cooperative behavior by stabilizing punishment at some n -th stage. We then explain how, once cooperation is stabilized in one group, it may spread through a multi-group population via cultural group selection. Finally, once cooperation is prevalent, we show how prosocial genes favoring cooperation and punishment may invade in the wake of cultural group selection.     

Preschool Children’s Behavioral Tendency toward Social Indirect Reciprocity

Social indirect reciprocity seems to be crucial in enabling large-scale cooperative networks among genetically unrelated individuals in humans. However, there are relatively few studies on social indirect reciprocity in children compared to adults. Investigating whether young children have a behavioral tendency toward social indirect reciprocity will help us understand how and when the fundamental ability to form cooperative relationships among adults is acquired. Using naturalistic observation at a nursery school, this study examined whether 5- to 6-year-olds show a behavioral tendency to engage in social indirect reciprocity in response to their peers’ prosocial behavior toward a third party. The results revealed that bystander children tended to display prosocial behavior toward their peers more frequently after observing these peers’ prosocial behavior toward third-party peers, compared with control situations; this suggests that 5- to 6-year-olds may have an essential behavioral tendency to establish social indirect reciprocity when interacting with peers in their daily lives. In addition, bystanders tended to display affiliative behavior after observing focal children’s prosocial behavior. In other words, observing peers’ prosocial behavior toward third-party peers evoked bystanders’ positive emotions toward the helpers. Considering both the present results and previous findings, we speculate that in preschoolers, such positive emotions might mediate the increase in the bystander’s prosocial behavior toward the helper. In addition, an intuitional emotional process plays an important role in the preschooler’s behavioral tendency toward social indirect reciprocity in natural interactions with peers.     

A friend in need: Time-dependent effects of stress on social discounting in men

Stress is often associated with a tend-and-befriend response, a putative coping mechanism where people behave generously towards others in order to invest in social relationships to seek comfort and mutual protection. However, this increase in generosity is expected to be directed only towards a delimited number of socially close, but not distant individuals, because it would be maladaptive to befriend everyone alike. In addition, the endocrinological stress response follows a distinct temporal pattern, and it is believed that tend-and-befriend tendencies can be observed mainly under acute stress. By contrast, the aftermath (> 1 h after) of stress is associated with endocrinological regulatory processes that are proposed to cause increased executive control and reduced emotional reactivity, possibly eliminating the need to tend-and-befriend. In the present experiment, we set out to investigate how these changes immediately and > 1 h after a stressful experience affect social-distance-dependent generosity levels, a phenomenon called social discounting. We hypothesized that stress has a time-dependent effect on social discounting, with decisions made shortly after (20 min), but not 90 min after stress showing increased generosity particularly to close others. We found that men tested 20 min after stressor onset indeed showed increased generosity towards close but not distant others compared to non-stressed men or men tested 90 min after stressor onset. These findings contribute to our understanding on how stress affects prosocial behavior by highlighting the importance of social closeness and the timing of stress relative to the decision as modulating factors in this type of decision making in men.     

Lazy group members are substitute helpers in carrion crows

In many cooperatively breeding societies, helping effort varies greatly among group members, raising the question of why dominant individuals tolerate lazy subordinates. In groups of carrion crows Corvus corone corone, helpers at the nest increase breeders'' reproductive success, but chick provisioning is unevenly distributed among non-breeders, with a gradient that ranges from individuals that work as much as the breeders to others that completely refrain from visiting the nest. Here we show that lazy non-breeders represent an insurance workforce that fully compensates for a reduction in the provisioning effort of another group member, avoiding a decrease in reproductive success. When we temporarily impaired a carer, decreasing its nest attendance, the laziest non-breeders increased their provisioning rate and individuals that initially refrained from visiting the nest started helping. Breeders, in contrast, did not increase chick provisioning. This shows that lazy non-breeders can buffer a sudden unfavourable circumstance and suggests that group stability relies on the potential contribution of group members in addition to their current effort.