Empathy incites a stable prosocial decision bias

Empathy toward suffering individuals serves as potent driver for prosocial behavior. However, it remains unclear whether prosociality induced by empathy for another person's pain persists once that person's suffering diminishes. To test this, participants underwent functional magnetic resonance imaging while performing a binary social decision task that involved allocation of points to themselves and another person. In block one, participants completed the task after witnessing frequent painful stimulation of the other person, and in block two, after observing low frequency of painful stimulation. Drift-diffusion modeling revealed an increased initial bias toward making prosocial decisions in the first block compared with baseline that persisted in the second block. These results were replicated in an independent behavioral study. An additional control study showed that this effect may be specific to empathy as stability was not evident when prosocial decisions were driven by a social norm such as reciprocity. Increased neural activation in dorsomedial prefrontal cortex was linked to empathic concern after witnessing frequent pain and to a general prosocial decision bias after witnessing rare pain. Altogether, our findings show that empathy for pain elicits a stable inclination toward making prosocial decisions even as their suffering diminishes.

Act generously when others do so: Majority influence on young children's sharing behavior

Children's sharing behavior is profoundly shaped by social norms within their society, and they can learn these norms by directly observing how most others share in their immediate environment. Here we systematically investigated the impact of majority influence on the sharing behavior of young Chinese children through three studies (N = 336, 168 girls). Four- and 6-year-olds were allowed to choose 10 favorite stickers and had an opportunity to engage in anonymous sharing. Before making the sharing decision, children were assigned to one of two conditions: watching a video in which three peers all shared 8 out of 10 stickers (i.e., the majority sharing condition) or making their decisions without watching the video (i.e., the control condition). Results showed that both the 4- and 6-year-old children shared more stickers in the majority sharing condition than in the control condition (Studies 1 & 2). Moreover, the influence of the majority had a stronger effect compared to the influence of a single role model. Children shared more stickers after observing three peers sharing, compared to watching one peer sharing three times (Study 2). Furthermore, children were less likely to copy the majority's non-sharing behavior when it came to giving away stickers without prosocial outcomes, which was particularly evident among 4-year-olds (Study 3). The results reveal that majority influence uniquely shapes children's sharing behavior and that children selectively follow the majority based on whether the behavior exhibits prosocial attributes. A video abstract of this article can be viewed at https://youtu.be/8qNNhf9754I?si=7YfpaFpcD_IjlXjJ RESEARCH HIGHLIGHTS: Observing a majority of three peers' unanimous generous sharing promoted sharing behavior in both 4- and 6-year-olds. The influence of three peers on children's sharing was stronger than that of one peer sharing three times. Four-year-olds, but not 6-year-olds, did not copy the non-sharing behavior of the majority as it did not lead to prosocial outcomes.

Individuals reciprocate negative actions revealing negative upstream reciprocity

Indirect reciprocity is widely recognized as a mechanism for explaining cooperation and can be divided into two sub-concepts: downstream and upstream reciprocity. Downstream reciprocity is supported by reputation; if someone sees you helping someone else, the person who sees this will think higher of you, and you will be more likely to be helped. Upstream reciprocity is helping someone because you are being helped by somebody else, which often happens in everyday life and experimental games. This paper focuses on the behavior of "take" and examines negative upstream reciprocity using an upstream reciprocity framework. The term "take" is defined as "to steal rather than give resources to others." "If something is taken from you, do you take from others?" is an important extension for indirect reciprocity research; subsequently, this paper discusses experiments conducted on whether negative upstream reciprocity is chained and what causes it. The results demonstrated differences between positive and negative upstream reciprocity. In analyzing the data of nearly 600 participants to determine the extent to which negative upstream reciprocity is observed and the causes of negative upstream reciprocity, the study found that If individual A takes resources from individual B, then B is more likely to take resources from a third-party, individual C. Notably, some causes of positive upstream reciprocity were found to have no effect or the opposite effect on negative upstream reciprocity. The results also demonstrate that the first person to take can cause a chain reaction. This paper demonstrates the importance of the first person not taking from someone else and suggests the need to consider various behavioral options for future research on cooperation.

Prospection and delay of gratification support the development of calculated reciprocity

Humans frequently benefit others strategically to elicit future cooperation. While such forms of calculated reciprocity are powerful in eliciting cooperative behaviors even among self-interested agents, they depend on advanced cognitive and behavioral capacities such as prospection (representing and planning for future events) and extended delay of gratification. In fact, it has been proposed that these constraints help explain why calculated reciprocity exists in humans and is rare or even absent in other animals. The current study investigated the cognitive foundation of calculated reciprocity by examining its ontogenetic emergence in relation to key aspects of children's cognitive development. Three-to-five-year-old children from the US (N = 72, mostly White, from mixed socioeconomic backgrounds) first completed a cognitive test battery assessing the cognitive capacities hypothesized to be foundational for calculated reciprocity. In a second session, children participated in a calculated reciprocity task in which they could decide how many resources to share with a partner who later had the opportunity to reciprocate (reciprocity condition) and with a partner who could not reciprocate (control condition). Results indicated a steep developmental emergence of calculated reciprocity between 3 and 5 years of age. Further analyses showed that measures of delay of gratification and prospection were important predictors of children's rate of calculated reciprocity, even when controlling for age and after including a measure of verbal ability. By contrast, theory of mind abilities were unrelated to children's reciprocal behavior. This is the first systematic investigation of essential cognitive capacities for calculated reciprocity. We discuss prospection and delay of gratification as two domain-general capacities that are utilized for calculated reciprocity and which could explain developmental as well as species-differences in cooperation.

Is Politeness Better than Impoliteness? Comparisons of Robot's Encouragement Effects Toward Performance, Moods, and Propagation

This study experimentally compared the effects of encouragement with polite/ impolite attitudes from a robot in a monotonous task from three viewpoints: performance, mood, and propagation. Experiment I investigated encouragement effects on performance and mood. The participants did a monotonous task during which a robot continuously provided polite, neutral, or impolite encouragement. Our experiment results showed that polite and impolite encouragement significantly improved performance more than neutral comments, although there was no significant difference between polite and impolite encouragement. In addition, impolite encouragement caused significantly more negative moods than polite encouragement. Experiment II determined whether the robot's encouragement influenced the participants' encouragement styles. The participants behaved similarly to the robot in Experiment I, i.e., they selected polite, neutral, and impolite encouragements by observing the progress of a monotonous task by a dummy participant. The experiment results, which showed that the robot's encouragement significantly influenced the participants' encouragement styles, suggest that polite encouragement is more advantageous than impolite encouragement.

Permitting immoral behaviour: A generalized compensation belief hypothesis

When are we more likely to permit immoral behaviours? The current research examined a generalized compensation belief hypothesis that individuals, as observers, would morally tolerate and accept someone paying forward unfair treatment to an innocent person as a means to compensate for the perpetrator's previously experienced mistreatment. Across five experiments (N = 1107) based on economic games (Studies 1-4) and diverse real-life scenarios (Study 5), we showed that participants, as observing third parties, were more likely to morally permit and engage in the same negative act once they knew about previous maltreatment of the perpetrator. This belief occurred even when the content of received and paid-forward maltreatment was non-identical (Study 2), when the negative treatment was received from a non-human target (Study 3) and when the maltreatment was intangible (e.g. material loss) or relational (e.g. social exclusion; Study 5). Perceived required compensation mediated the effect of previous maltreatment on moral permission (Studies 4 and 5). The results consistently suggest that people's moral permission of immoral behaviours is influenced by perpetrator's previous mistreatment, contributing to a better understanding of the nature and nuances of our sense of fairness and contextualized moral judgement.

The impact of social comparison and (un)fairness on upstream indirect reciprocity: Evidence from ERP

Event-related potential (ERP) technology and the dictator game paradigm are used to explore the formation mechanism of upstream indirect reciprocity behaviors. We design a within subject experiment of 3 (social comparison: upward versus parallel versus downward) × 2 (treatment: fair versus unfair) involving 49 subjects. In the first round of allocations, subjects are forced to accept a monetary amount allocated to them by another player. In the second round, subjects assume the role of allocator and divide a monetary amount between themselves and a third party. Our results show the following: 1) Having received fair treatment from someone else, individuals engaged in downward comparison are more inclined to reciprocate the fairness they had received to a third party compared to individuals in parallel and upward comparison conditions. If individuals receive unfair treatment, they tend to repeat this behavior to a third party regardless of which social comparison condition they are in; 2) Under the condition of upward comparison, individuals receiving unfair treatment exhibit greater FRN amplitude and less P300 amplitude, but in parallel and downward comparison conditions, there is no significance in FRN and P300 amplitude between individuals receiving fair and unfair treatment.

Misrepresentation of group contributions undermines conditional cooperation in a human decision making experiment

Cooperative behaviour can evolve through conditional strategies that direct cooperation towards interaction partners who have themselves been cooperative in the past. Such strategies are common in human cooperation, but they can be vulnerable to manipulation: individuals may try to exaggerate their past cooperation to elicit reciprocal contributions or improve their reputation for future gains. Little is known about the prevalence and the ramifications of misrepresentation in human cooperation, neither in general nor about its cultural facets (self-sacrifice for the group is valued differently across cultures). Here, we present a large-scale interactive decision making experiment (N = 870), performed in China and the USA, in which individuals had repeated cooperative interactions in groups. Our results show that (1) most individuals from both cultures overstate their contributions to the group if given the opportunity, (2) misrepresentation of cooperation is detrimental to cooperation in future interactions, and (3) the possibility to build up a personal reputation amplifies the effects of misrepresentation on cooperation in China, but not in the USA. Our results suggest that misrepresentation of cooperation is likely to be an important factor in (the evolution of) human social behaviour, with, depending on culture, diverging impacts on cooperation outcomes.

Supervisor Bottom-Line Mentality, Performance Pressure, and Workplace Cheating: Moderating Role of Negative Reciprocity

Employee cheating at the workplace has reached epidemic proportions and is putting a significant dent on the revenues of corporations. This study evaluates workplace cheating behavior as a consequence of supervisor bottom-line mentality with performance pressure as the mediating mechanism. Most importantly, it scrutinizes the moderating function of negative reciprocity belief in the relation between bottom-line mentality, performance pressure, and cheating in a moderated-mediation model, through the lens of displaced aggression theory. We systematically conduct time-lagged studies in two different populations (Pakistan and United States). Data analysis reveals that (1) bottom-line mentality positively influences workplace cheating behavior through performance pressure and (2) negative reciprocity moderated this indirect relationship. Theoretical and practical implications are discussed.

The impact of positive and negative testimony on children's attitudes toward others

Children can identify who is benevolent or malevolent not only through first-hand experiences and observations but also from the testimony of others. In this study, we investigated whether 5- and 7-year-olds (N = 128) would form their attitudes toward others after hearing testimony about that person’s past moral behavior and whether the valence of testimony would differently influence the children. In the positive condition, half of the participants gained information about three puppets: puppet A’s prosocial behavior by their own first-hand observation, testimony about puppet B’s past prosocial behavior, and testimony about puppet C’s past neutral behavior. In the negative condition, the other half also learned information about the three puppets: puppet A’s antisocial behavior by their own first-hand observation, testimony about puppet B’s past antisocial behavior, and testimony about puppet C’s past neutral behavior. Then they engaged in tasks that measured their behavioral attitudes toward the puppets and evaluated the goodness of each puppet to assess their attitudes at a cognitive level. Our results concluded that the children form their behavioral attitudes toward others based on testimony starting at the age of 7, and attitude formation at the cognitive level based on testimony is seen at age 5. Negative testimony, rather than positive testimony, influences the children’s attitudes toward others. In addition, the 7-year-olds’ use of testimony differs depending whether they are the allocators or the receivers of rewards. Our findings deepen understanding of how children rely on the verbal information around themselves when they navigate interactions with others.

Sniffing the human body volatile hexadecanal blocks aggression in men but triggers aggression in women

In terrestrial mammals, body volatiles can effectively trigger or block conspecific aggression. Here, we tested whether hexadecanal (HEX), a human body volatile implicated as a mammalian-wide social chemosignal, affects human aggression. Using validated behavioral paradigms, we observed a marked dissociation: Sniffing HEX blocked aggression in men but triggered aggression in women. Next, using functional brain imaging, we uncovered a pattern of brain activity mirroring behavior: In both men and women, HEX increased activity in the left angular gyrus, an area implicated in perception of social cues. HEX then modulated functional connectivity between the angular gyrus and a brain network implicated in social appraisal (temporal pole) and aggressive execution (amygdala and orbitofrontal cortex) in a sex-dependent manner consistent with behavior: increasing connectivity in men but decreasing connectivity in women. These findings implicate sex-specific social chemosignaling at the mechanistic heart of human aggressive behavior.

Direct and indirect reciprocity among individuals and groups

Direct and indirect reciprocity are two fundamental mechanisms that promote prosocial behavior within groups and across societies. Here, we review recent work that illustrates how a (direct and indirect) reciprocity framework can illuminate our understanding of several factors related to prosocial behavior - namely group membership, gossip, and third-party punishment. We propose that each of these factors can promote prosocial behavior via proximate psychological mechanisms related to direct and indirect reciprocity: reputational concern, expectations, and anticipation of future interaction. Finally, we discuss the implications of adopting such a framework and highlight a number of avenues for future research.

Determinants and modulators of human social decisions

Social decision making is a highly complex process that involves diverse cognitive mechanisms, and it is driven by the precise processing of information from both the environment and from the internal state. On the one hand, successful social decisions require close monitoring of others' behavior, in order to track their intentions; this can guide not only decisions involving other people, but also one's own choices and preferences. On the other hand, internal states such as own reward or changes in hormonal and neurotransmitter states shape social decisions and their underlying neural function. Here, we review the current literature on modulators and determinants of human social decisions.

Monetary payoffs modulate reciprocity expectations in outcome evaluations: An event-related potential study

Choosing cooperation or aggression relies on reciprocity preferences which refer to the tendency of an individual to return cooperative or aggressive action for cooperative or aggressive action (i.e., positive or negative reciprocity preference). The reciprocity preference is positively correlated with reciprocity expectation, wherein individuals with stronger reciprocity preferences may have higher expectations than future cooperative or aggressive behavior should be delivered by beneficiaries (positive reciprocity expectation) or victims (negative reciprocity expectation). Although previous studies have demonstrated that the presence of monetary payoffs enhances reciprocity preferences, the modulation of monetary payoffs in reciprocity expectations remains unclear. Using event-related potentials (ERPs), we examined how monetary payoffs modulated reciprocity expectations by adopting the Chicken game. Participants were asked to choose between cooperation and aggression with a putative opponent in the Chicken game involving the monetary (vs. non-monetary) payoffs. Participants' electroencephalogram (EEG) was recorded when they saw the opponent's cooperative or aggressive decision. Results showed that compared to the non-monetary payoff trials, the feedback-related negativity (FRN) effect in response to the opponent's decisions was stronger following the participant's aggressive decision in the monetary payoff trials, whereas P3 was insensitive to monetary payoffs. These findings suggest that monetary payoffs heighten expectations of negative reciprocity at the earlier and automatic outcome processing stage.

Why do preschoolers perpetuate inequalities? Theoretical perspectives on inequity preferences in the face of emerging concerns for equality

Recent research has shown that preschool children tend to preferentially allocate resources to rich than to poor others. The findings that young children tend to perpetuate inequalities are puzzling given classical developmental theories that largely focused on the emergence of equality and equity in childhood. In this review, we first sketch the early ontogeny of fairness concerns before providing an overview on studies reporting perpetuation of inequality in young children. We review four classical theories (Piaget, Kohlberg, Damon, Social Domain Theory) and discuss how they would account for this phenomenon. We then introduce four recent theoretical models that directly speak to the underlying psychological processes; the affective preference model, the reciprocity-based strategic model, the numerical matching model, and the normative model. We highlight the key tenets of each model, their relation to other developmental processes, and the strength of the empirical evidence. From each model, we derive specific hypotheses. Finally, in an integrative section we discuss how the models might relate to each other, highlight connections to other research areas, and present avenues for future research.

(Peer) Group influence on children's prosocial and antisocial behavior

This study investigates the influence of moral ingroup versus outgroup behavior on 5- and 6-year-olds' and 8- and 9-year-olds' own moral behavior (N = 296). After minimal group assignment, children in Experiment 1 observed adult ingroup or outgroup members engaging in prosocial sharing or antisocial stealing before they themselves had the opportunity to privately donate stickers or take away stickers from others. Older children shared more than younger children, and prosocial models elicited higher sharing. Surprisingly, group membership had no effect. Experiment 2 investigated the same question using peer models. Children in the younger age group were significantly influenced by ingroup behavior, whereas older children were not affected by group membership. Additional measures reveal interesting insights into how moral ingroup and outgroup behavior affects intergroup attitudes, evaluations, and choices.

The Origins and Psychology of Human Cooperation

Humans are an ultrasocial species. This sociality, however, cannot be fully explained by the canonical approaches found in evolutionary biology, psychology, or economics. Understanding our unique social psychology requires accounting not only for the breadth and intensity of human cooperation but also for the variation found across societies, over history, and among behavioral domains. Here, we introduce an expanded evolutionary approach that considers how genetic and cultural evolution, and their interaction, may have shaped both the reliably developing features of our minds and the well-documented differences in cultural psychologies around the globe. We review the major evolutionary mechanisms that have been proposed to explain human cooperation, including kinship, reciprocity, reputation, signaling, and punishment; we discuss key culture-gene coevolutionary hypotheses, such as those surrounding self-domestication and norm psychology; and we consider the role of religions and marriage systems. Empirically, we synthesize experimental and observational evidence from studies of children and adults from diverse societies with research among nonhuman primates.

Paying it back and forward: The impact of experiencing and observing others' sharing and stinginess on preschoolers' own sharing behavior and expectations

Recent research suggests that children's sharing behavior is affected by experiencing or observing others' sharing. These effects have been studied within research on the development of reciprocity and the effects of social modeling. In the current study, direct and indirect types of reciprocity and social modeling were assessed in 3- to 6-year-old children in three experiments (overall N = 382). In each experiment, we explored whether negative and positive social behavior were similarly paid back and forward in each of the different types of reciprocity. Moreover, we assessed the extent to which children reciprocated toward the protagonist who had performed the actual behavior and toward a neutral other. In Experiment 1, children experienced another's sharing behavior as recipients and could then allocate resources to this character and a neutral other. In Experiment 2, children observed another's sharing behavior and could then allocate resources to this character and a neutral other. In Experiment 3, children were asked to predict another protagonist's sharing in the same context as in Experiment 1. Overall, children treated the protagonist and the neutral other similarly and predicted others to do the same. Yet, they were more likely to reciprocate negative acts in indirect types of reciprocity. The results are interpreted with respect to the impact of observational learning and representational development on children's social behavior.

Paying it forward: The development and underlying mechanisms of upstream reciprocity

Two studies investigated the development and motivations underlying children's upstream reciprocity. In Study 1, 3- and 4-year-olds (n = 40 per age group) received or did not receive help while playing a game. Subsequently, children could share stickers with a new child. The 4-year-olds, but not the 3-year-olds, showed evidence of upstream reciprocity: Those who had received help were more generous toward the new child. Study 2 (N = 46) replicated the results with 4-year-olds and found evidence for a gratitude-like motivation underlying the upstream reciprocity: Children who received help evaluated the benefactor more positively, and positive evaluations of the benefactor correlated with children's upstream reciprocity. Thus, upstream reciprocity emerges by 4 years of age and may already be motivated by a gratitude-like mechanism.

Normative foundations of reciprocity in preschoolers

Reciprocity has been suggested to represent a crucial normative principle for humans. The current study aimed to investigate the normative foundations of reciprocity and the development of a reciprocity norm in young children. To this end, we presented 3- to 6-year-olds with three conditions. In one condition, a protagonist reciprocated sharing a large proportion of resources. In another condition, a protagonist reciprocated sharing a small proportion of resources. In a third condition, a protagonist did not reciprocate sharing a large proportion by giving rather few resources and, thus, violated a reciprocity norm. Results show that 5- and 6-year-olds endorse compliance with a reciprocity norm, which is reflected in their evaluations of the protagonists and their spontaneous verbal affirmation of reciprocal behavior. In contrast, 3- and 4-year-olds exclusively valued general prosociality, neglecting reciprocity. This indicates that children acquire a norm of reciprocity during the course of the preschool period.