What makes humans moral beings? This question can be understood either as a proximate question or as an ultimate question. The question is about the mental and social mechanisms that produce moral judgments and interactions, and has been investigated by psychologists and social scientists. The question is about the fitness consequences that explain why humans have morality, and has been discussed by evolutionary biologists in the context of the evolution of cooperation. Our goal here is to contribute to a fruitful (...) articulation of such proximate and ultimate explanations of human morality. We develop an approach to morality as an adaptation to an environment in which individuals were in competition to be chosen and recruited in mutually advantageous cooperative interactions. In this environment, the best strategy is to treat others with impartiality and to share the costs and benefits of cooperation equally. Those who offer less than others will be left out of cooperation; conversely, those who offer more will be exploited by their partners. In line with this mutualistic approach, the study of a range of economic games involving property rights, collective actions, mutual help and punishment shows that participants' distributions aim at sharing the costs and benefits of interactions in an impartial way. In particular, the distribution of resources is influenced by effort and talent, and the perception of each participant's rights on the resources to be distributed. (shrink)

From an evolutionary point of view, the function of moral behaviour may be to secure a good reputation as a co-operator. The best way to do so may be to obey genuine moral motivations. Still, one's moral reputation maybe something too important to be entrusted just to one's moral sense. A robust concern for one's reputation is likely to have evolved too. Here we explore some of the complex relationships between morality and reputation both from an evolutionary and a cognitive (...) point of view. (shrink)

In the past decade, experiments on altruistic punishment have played a central role in the study of the evolution of cooperation. By showing that people are ready to incur a cost to punish cheaters and that punishment help to stabilise cooperation, these experiments have greatly contributed to the rise of group selection theory. However, despite its experimental robustness, it is not clear whether altruistic punishment really exists. Here, I review the anthropological literature and show that hunter-gatherers rarely punish cheaters. Instead, (...) they avoid dealing with them and switch to other partners. I suggest that these data are better explained by individual selection, and in particular by partner choice models, in which individuals are in competition to be recruited by cooperative partners. I discuss two apparent problems for partner choice theories: large-scale cooperation and punishments in economic games. I suggest that rather than favouring group selection theory, these two phenomena provide evidence in favour of individual selection: (1) people produce large-scale cooperation through institutions in which punishment is not altruistic but rewarded on an individual basis; (2) punishment in experimental games can be explained without altruism and is indeed often better explained by individual interests. (shrink)

Punitive behaviours are often assumed to be the result of an instinct for punishment. This instinct would have evolved to punish wrongdoers and it would be the evidence that cooperation has evolved by group selection. Here, I propose an alternative theory according to which punishment is a not an adaptation and that there was no specific selective pressure to inflict costs on wrongdoers in the ancestral environment. In this theory, cooperation evolved through partner choice for mutual advantage. In the ancestral (...) environment, individuals were in competition to be recruited in cooperative ventures and it was vital to share the benefits of cooperation in a mutually advantageous manner. If individuals took a bigger share of the benefits, their partners would leave them for more interesting partners. If they took a smaller share, they would be exploited by their partners who would receive more than what they had contributed to produce. This competition led to the selection of a sense of fairness, a cognitive adaptation aiming to share equally the benefits of cooperation in order to attract partners. In this theory, punishment is not necessary for the evolution of cooperation. Punitive behaviours are only a way to restore fairness by compensating the victim or penalizing the culprit. Drawing on behavioural economics, legal anthropology, and cognitive psychology, I show that empirical data fit better with this framework than with the theory of group selection. When people punish, they do so to restore fairness rather than to help the group. (shrink)

Henrich et al.’s article fleshes out in a very useful and timely manner comments often heard but rarely published about the extraordinary cultural imbalance in the recruitment of participants in psychology experiments and the doubt this casts on generalization of findings from these “weird” samples to humans in general. The authors mention that one of the concerns they have met in defending their views has been of a methodological nature: “the observed variation across populations may be due to various methodological (...) artifacts that arise from translating experiments across contexts” (sect. 7.2, para. 1). Here we want to express a less sweeping methodological concern. While accepting the general conclusions and recommendations of the article, we believe they should be complemented with a.. (shrink)

The belief in immanent justice is the expectation that the universe is designed to ensure that evil is punished and virtue rewarded. What makes this belief so ‘natural’? Here, we suggest that this intuition of immanent justice derives from our evolved sense of fairness. In cases where a misdeed is followed by a misfortune, our sense of fairness construes the misfortune as a way to compensate for the misdeed. To test this hypothesis, we designed a set of studies in which (...) we show that people who do not believe in immanent justice are nonetheless implicitly influenced by intuitions of immanent justice. Strikingly, this effect disappears when the misfortune is disproportionate compared to the misdeed: In this case, justice is not restored and participants lose the intuition of immanent justice. Following recent theories of religion, we suggest that this intuition contributes to the cultural success of beliefs in immanent justice. (shrink)

I am grateful to have received so many stimulating commentaries from interested colleagues regarding the psychological origins of the Industrial Revolution and the role of evolutionary theory in understanding historical phenomena. Commentators criticized, extended, and explored the implications of the perspective I presented, and I wholeheartedly agree with many commentaries that more work is needed. In this response, I thus focus on what is needed to further test the psychological origins of the Industrial Revolution. Specifically, I argue, in agreement with (...) many commentators, that we need: better data about standards of living, psychological preferences, and innovation rates ; better models to understand the role of resources in driving cultural evolution and the multiple aspects of the behavioral constellation of affluence ; and better predictions and better statistical instruments to disentangle the possible mechanisms behind the rise of innovativeness. (shrink)

Humans pay close attention to the reputational consequences of their actions. Recent experiments indicate that even very subtle cues that one is being observed can affect cooperative behaviors. Expressing our opinions about the morality of certain acts is a key means of advertising our cooperative dispositions. Here, we investigated how subtle cues of being watched would affect moral judgments. We predicted that participants exposed to such cues would affirm their endorsement of prevailing moral norms by expressing greater disapproval of moral (...) transgressions. Participants read brief accounts of two moral violations and rated the moral acceptability of each violation. Violations were more strongly condemned in a condition where participants were exposed to surveillance cues (an image of eyes interposed between the description of the violation and the associated rating scale) than in a control condition (in which the interposed image was of flowers). We discuss the role that public declarations play in the interpersonal evaluation of cooperative dispositions. (shrink)

Our discussion of the commentaries begins, at the evolutionary level, with issues raised by our account of the evolution of morality in terms of partner-choice mutualism. We then turn to the cognitive level and the characterization and workings of fairness. In a final section, we discuss the degree to which our fairness-based approach to morality extends to norms that are commonly considered moral even though they are distinct from fairness.

Strong reciprocity theorists claim that punishment has evolved to promote the good of the group and to deter cheating. By contrast, weak reciprocity suggests that punishment aims to restore justice (i.e., reciprocity) between the criminal and his victim. Experimental evidences as well as field observations suggest that humans punish criminals to restore fairness rather than to support group cooperation.

Since the Industrial Revolution, human societies have experienced high and sustained rates of economic growth. Recent explanations of this sudden and massive change in economic history have held that modern growth results from an acceleration of innovation. But it is unclear why the rate of innovation drastically accelerated in England in the eighteenth century. An important factor might be the alteration of individual preferences with regard to innovation resulting from the unprecedented living standards of the English during that period, for (...) two reasons. First, recent developments in economic history challenge the standard Malthusian view according to which living standards were stagnant until the Industrial Revolution. Pre-industrial England enjoyed a level of affluence that was unprecedented in history. Second, behavioral sciences have demonstrated that the human brain is designed to respond adaptively to variations in resources in the local environment. In particular, Life History Theory, a branch of evolutionary biology, suggests that a more favorable environment should trigger the expression of future-oriented preferences. In this paper, I argue that some of these psychological traits – a lower level of time discounting, a higher level of optimism, decreased materialistic orientation, and a higher level of trust in others – are likely to increase the rate of innovation. I review the evidence regarding the impact of affluence on preferences in contemporary as well as past populations, and conclude that the impact of affluence on neurocognitive systems may partly explain the modern acceleration of technological innovations and the associated economic growth. (shrink)

A long tradition of research in WEIRD (Western, Educated, Industrialized, Rich, Democratic) countries has investigated how people weigh individual welfare versus group welfare in their moral judgments. Relatively less research has investigated the generalizability of results across non-WEIRD populations. In the current study, we ask participants across nine diverse cultures (Bali, Costa Rica, France, Guatemala, Japan, Madagascar, Mongolia, Serbia, and the USA) to make a series of moral judgments regarding both third-party sacrifice for group welfare and first-person sacrifice for group (...) welfare. In addition to finding some amount of cross-cultural variation on most of our questions, we also find two cross-culturally consistent judgments: (1) when indi- viduals are in equivalent situations, overall welfare should be maximized, and (2) harm to individuals should be taken into account, and some types of individual harm can trump overall group welfare. We end by discussing the specific pattern of variable and consistent features in the context of evolutionary theories of the evolution of morality. (shrink)