Making amends

Conflict is an integral, and potentially disruptive, element in the lives of humans and other group-living animals. But conflicts are often settled, sometimes within minutes after the altercation has ended. The goal of this paper is to understand why primates, including humans, make amends. Primatologists have gathered an impressive body of evidence which demonstrates that monkeys and apes use a variety of behavioral mechanisms to resolve conflicts. Peaceful post-conflict interactions in nonhuman primates, sometimes labeled "reconciliation," have clear and immediate effects upon former adversaries, relieving uncertainty about whether aggression will continue, reducing stress, increasing tolerance, and reducing anxiety about whether aggressors will resume aggression toward former victims. However, the long-term effects of these interactions are less clearly established, leaving room to debate the adaptive function of conflict resolution strategies among primates. It is possible that reconciliatory behavior enhances the quality of valued, long-term social relationships or that reconciliatory interactions are signals that the conflict has ended and the actor’s intentions are now benign. Both of these hypotheses may help us to understand how and why monkeys, apes, and humans make amends. Over the past few years I have discussed the ideas in this paper with a number of colleagues, whose constructive comments and criticism have helped me to shape my thoughts about PPCS. I am grateful for feedback from F. Aureli, R. Boyd, D. Castles, D. Cheney, M. Cords, L. Fairbanks, S. Harcourt, S. Hrdy, B. Kaldor, R. Seyfarth, D. Smucny, and K. Stewart. Joan Silk is a professor in and chair of the Department of Anthropology at the University of California, Los Angeles. She has long-standing interests in the evolution of social behavior and the dynamics of social interactions among primates. She has conducted research on chimpanzees at the Gombe Stream National Park, on free-ranging baboons in Kenya and Botswana, and on captive bonnet macaques.     

Costly apologies communicate conciliatory intention: an fMRI study on forgiveness in response to costly apologies

Reconciliation is an integral part of our social lives. Nevertheless, if a victim perceives the risk of further exploitation by his/her transgressor as non-negligible, the victim may well have difficulty forgiving the transgressor. Therefore, a key ingredient of reconciliation is the transgressor's sincere apology. Theoretical and empirical studies have shown that transgressors can make their apologies credible by incurring a substantial cost. Therefore, we hypothesized that costly apologies, compared to non-costly apologies (i.e., simply saying “sorry”), would effectively communicate a transgressor's conciliatory intention. In a functional magnetic resonance imaging (fMRI) study, participants were asked to imagine a friend committing a mild interpersonal transgression (e.g., standing up the participant) and then apologizing in a costly fashion, apologizing in a non-costly fashion, or not apologizing at all. Compared to non-costly apologies and non-apologies, costly apologies (signals of conciliatory intention) more strongly activated the theory-of-mind network (i.e., bilateral temporoparietal junction, precuneus, medial prefrontal cortex). Moreover, we did not observe any significant differences in brain responses to non-costly apologies and non-apology controls. These results underscore the importance of costly signals in human communication and in human peace-making in particular.     

宽恕的生理及神经机制研究进展

宽恕作为人类所独有一种美德,对人们来说并不陌生,但对于宽恕的系统研究却仅始于上个世纪80、90年代。本文采用文献法着重从生理心理、神经证据等方面对宽恕认知神经科学方面的研究进行了梳理和整合,最后对该研究领域未来的发展方向进行了展望。     

Indirect reciprocity among imperfect individuals

Reciprocal cooperation occurs when the overall benefits of receiving help exceed the costs of donating help (Q. Rev. Biol. 46 (197) 35). That is, individuals in good condition--for whom the pertinent costs are relatively small; donate help in order to secure reciprocity in their hour of need--when the benefits of receiving a donation are large. Consequently, reciprocity occurs among individuals who occasionally need help. In particular, such individuals will be unable to help others, no matter how deserving, when in need of help themselves--involuntary defection. This paper deals with the effects of involuntary defection in the context of a specific model of indirect reciprocity (i.e. reciprocal altruism that is directed toward all the cooperative members of the community) due to Nowak and Sigmund (J. Theor. Biol.194 (1998b) 561: Sections 2-4). In that model, the authors formulate the decision rules for conditional cooperation in the context of indirect reciprocity, and demonstrate that these decision rules can account for a long-term persistence of cooperation. Here we show that addition of involuntary defection to the decision rules formulated by Nowak and Sigmund results in indirect reciprocity that is evolutionary stable under appropriate conditions. Moreover, for a wide range of parameter values, evolutionary stability of cooperation requires a mixture of conditional- and unconditional-altruist behaviors. To recollect, unconditional altruist strategy can be viewed as conditional altruist strategy sans the ability to decide when the help-soliciting individual should be refused help. That is, given involuntary defection, stability of cooperation requires an occasional forgiveness, if only by default, of a failure to donate help. Thus, we see that evolutionary stable indirect reciprocity does not require perfection in either the ability to assess the merits of the help-soliciting individuals, or the ability to donate help when it is merited. On the contrary, we are forced to conclude that reciprocity, at least in the current case, is stable only among imperfect individuals.     

Wild justice and fair play: cooperation,forgiveness, and morality in animals

In this paper I argue that we can learn much about ‘wild justice’ and the evolutionary origins of social morality – behaving fairly – by studying social play behavior in group-living animals, and that interdisciplinary cooperation will help immensely. In our efforts to learn more about the evolution of morality we need to broaden our comparative research to include animals other than non-human primates. If one is a good Darwinian, it is premature to claim that only humans can be empathic and moral beings. By asking the question ‘What is it like to be another animal?’ we can discover rules of engagement that guide animals in their social encounters. When I study dogs, for example, I try to be a ‘dogocentrist’ and practice ‘dogomorphism.’ My major arguments center on the following ‘big’ questions: Can animals be moral beings or do they merely act as if they are? What are the evolutionary roots of cooperation, fairness, trust, forgiveness, and morality? What do animals do when they engage in social play? How do animals negotiate agreements to cooperate, to forgive, to behave fairly, to develop trust? Can animals forgive? Why cooperate and play fairly? Why did play evolve as it has? Does ‘being fair’ mean being more fit – do individual variations in play influence an individual's reproductive fitness, are more virtuous individuals more fit than less virtuous individuals? What is the taxonomic distribution of cognitive skills and emotional capacities necessary for individuals to be able to behave fairly, to empathize, to behave morally? Can we use information about moral behavior in animals to help us understand ourselves? I conclude that there is strong selection for cooperative fair play in which individuals establish and maintain a social contract to play because there are mutual benefits when individuals adopt this strategy and group stability may be also be fostered. Numerous mechanisms have evolved to facilitate the initiation and maintenance of social play to keep others engaged, so that agreeing to play fairly and the resulting benefits of doing so can be readily achieved. I also claim that the ability to make accurate predictions about what an individual is likely to do in a given social situation is a useful litmus test for explaining what might be happening in an individual's brain during social encounters, and that intentional or representational explanations are often important for making these predictions.     

Cardiovascular Response to Interpersonal Provocation and Mental Arithmetic among High and Low Hostile Young Adult Males

To examine the relation between hostility and cardiovascular reactivity to stress, 42 undergraduate men were categorized into high and low hostile groups based on responses to the Cook Medley Hostility Scale. Participants engaged in two laboratory tasks: a Cognitive Task (mental arithmetic) and a Social Task (confrontation role-play). Cardiovascular measures of heart rate and blood pressure were obtained throughout rest and task periods and participants provided ratings of state anger and forgiveness following task completion. Results revealed that low hostile participants exhibited greater systolic blood pressure (SBP) responses to both tasks than high hostile participants (p < .05), but no significant group differences were observed for heart rate or diastolic blood pressure. High hostile men reported greater state anger during resting conditions and less forgiveness following completion of tasks than low-hostile counterparts, but neither of these findings moderated the relation between hostility and SBP reactivity. Higher ratings of forgiveness were associated with lower SBP reactivity. These findings show that hostility is not always associated with exaggerated cardiovascular reactivity to stress, and the influence of various moderating factors should be considered in elucidating this relation.