How intergroup relation moderates group bias in Third-Party Punishment

Render help or stand by? The effect of group size on third-party punishment and its neural mechanisms

Third-party punishment (TPP) is the punishment that an individual executes on a violator as a third party or observer to maintain social norms. Many studies have provided insights into the neural mechanisms of third-party punishment in group environments. Still, only some studies have focused on the neural mechanisms of third-party punishment in different group sizes. This study used EEG analysis to explore the effects of group size on third-party punishment and its neural activity characteristics from the context of gain and loss. The results show that the punishment rate and amount of the third party in the small group size and loss context were significantly higher than that in the large group size and gain context. EEG results showed that third-party punishment in small groups induced greater P2 than in large groups. In the loss context, the third-party punishment in the large group size induced more negative LNP and activated more theta band activation than in the small group. The results showed that the motivation of the third party to seek a positive reputation in the small size exceeds the balance of its economic interests and tends to punish the violator for maintaining fair norms. The loss context plays a promoting role in this process. However, in the large size, the third-party consideration of its interests was stronger than the willingness to maintain social norms. This study provided neuroscientific evidence for third-party punishment to maintain fair norms in a group environment and further explanations from neuroscience for understanding Indirect Reciprocity Theory.

How retributive motives shape the emergence of third-party punishment across intergroup contexts

This study examines how retributive motives-the desire to punish for the purpose of inflicting harm in the absence of future benefits-shape third-party punishment behavior across intergroup contexts. Six- to nine-year-olds (N = 151, Mage = 8.00, SDage = 1.15; 54% White, 18% mixed ethnicities, 17% Asian American; 46% female; from the USA) could punish ingroup, outgroup, or non-group transgressors by removing positive resources and allocating negative ones. Both punishments were described as retributive, yet allocating negative resources was perceived as more retributive than removing positive ones. We predicted that children would punish outgroups more so than ingroups and that this effect would be especially pronounced when punishment is perceived as particularly retributive. The results did not align with this prediction; instead, children similarly punished all agents.

Win-win or lose-lose: Children prefer the form of equality

In middle childhood, children's sense of fairness further develops, they are willing to pay a cost to maintain equality. Win-win and lose-lose are two forms of equality. Win-win equality refers to both parties maximizing benefits, while lose-lose equality means both parties incurring the maximum loss. Win-win equality allows third party upholding fairness to gain more reputational benefits without the violator being punished, embodying the principle of "benefiting oneself without harming others". On the other hand, lose-lose equality is a more deterrent form of fairness with the violator getting punished, and the third-party might experience a situation of "effort without appreciation." However, the specific form of equality which school-aged children prefer still requires further exploration. Therefore, adopting the dictator game paradigm of third-party punishment, we design two experiments to investigate the fairness preference of first to fourth-grade children when acting as a third party and to clarify patterns of age-related changes. Study 1 (N = 111) explored children's preferred form of fairness under advantageous inequity conditions. Study 2 (N = 122) further examined children's fairness preferences in disadvantageous inequity situations. The findings suggest that when confronted with inequitable distributions, whether rooted in disadvantageous or advantageous inequity, children display a notable tendency to utilize third-party punishment to achieve an equal allocation. Meanwhile, this tendency strengthens as they progress in grade levels. Notably, children consistently manifest a preference for win-win equality, highlighting their inclination towards mutually beneficial outcomes.

Group membership and adolescents' third-party punishment: a moderated chain mediation model

Third-party punishment (TPP) reflects people's social preference for fairness norms and is fundamental to maintaining fairness norms on a large scale. Several empirical studies have shown that the offender's group membership impacts TPP, but the detailed mechanisms have yet to be fully elucidated. The current study used the third-party punishment game task to explore the relationship between group membership, perceived unfairness, anger, and adolescents' TPP. A total of 306 teenagers aged 12 to 15 were chosen as subjects through cluster sampling. The results showed that group membership (classmate vs. stranger) and gender can affect adolescents' TPP together, which manifests as adolescents enacting significantly harsher punishments on strangers than on classmates, especially for boys. Group membership indirectly affects TPP through the mediating effects of perceived unfairness, anger and through a chain mediation of perceived unfairness and anger. Moreover, gender positively moderate the relationship between group membership and perceived unfairness. Specifically, group membership significantly affects boys' perceived unfairness, but cannot predict girls' perceived unfairness. The above results can be used to guide adolescents toward appropriate justice concepts and moral awareness, thus enhancing TPP.

Human societal development: is it an evolutionary transition in individuality?

An evolutionary transition in individuality (ETI) occurs when a previously independent organism becomes a lower level unit within a higher hierarchical level (for example, cells in an organism, ants in a colony). Using archaeological and historical accounts from the last 12 000 years, I empirically examine the proposition that human society increasingly functions as a higher hierarchical level within which individuals integrate as lower level units. I evaluate human societal development with respect to three criteria that together indicate complexity in biological systems and serve as an operationalization scheme for ETIs: size, inseparability and specialization. The size of the largest polity has increased seven orders of magnitude, from hundreds to billions. Inseparability became nearly complete since Mesopotamian city-states, following the first appearance of intricate specialization (division of labour). Connectivity within a polity has increased rapidly during the last few centuries, and particularly within the last few decades. In view of these results, I formulate the following hypothesis: human society is undergoing an evolutionary transition in individuality, driven by socio-cultural-technological processes. This proposition requires a detailed theoretical basis and further empirical testing. I propose four predictions derived from the hypothesis that may be used to test it. This article is part of the theme issue 'Human socio-cultural evolution in light of evolutionary transitions'.

Culture and group-functional punishment behaviour

Humans often 'altruistically' punish non-cooperators in one-shot interactions among genetically unrelated individuals. This poses an evolutionary puzzle because altruistic punishment enforces cooperation norms that benefit the whole group but is costly for the punisher. One key explanation is that punishment follows a social-benefits logic: it is eminently normative and group-functional (drawing on cultural group selection theories). In contrast, mismatch-based deterrence theory argues that punishment serves the individual-level function of deterring mistreatment of oneself and one's allies, hinging upon the evolved human coalitional psychology. We conducted multilateral-cooperation experiments with a sample of Spanish Romani people (Gitanos or Calé) and the non-Gitano majority. The Gitanos represent a unique case study because they rely heavily on close kin-based networks and display a strong ethnic identity. We find that Gitano non-cooperators were not punished by co-ethnics in only-Gitano (ethnically) homogeneous groups but were harshly punished by other Gitanos and by non-Gitanos in ethnically mixed groups. Our findings suggest the existence of culture-specific motives for punishment: Gitanos, especially males, appear to use punishment to protect their ethnic identity, whereas non-Gitanos use punishment to protect a norm of universal cooperation. Only theories that consider normative, group-functional forces underlying punishment behaviour can explain our data.