A well-known mantra is that while selfish (i.e. prone to cheating) individuals out-compete altruistic (i.e. prone to cooperating) individuals within groups, internally altruistic groups out-compete selfish groups (Wilson & Wilson, 2007). The key question is then: how to make individuals cooperate? This question has been addressed by a host of scholars in different disciplines. To give a few examples, political scientists suggest that the setup of institutions may reflect power arrangements favouring self-interested political actors, but that well-designed institutions are more likely to endure when they increase the overall welfare of the group (Tang, 2011). Economists have employed behavioural experiments to demonstrate that the predisposition to cooperate with others goes hand-in-hand with the tendency to punish those who violate the norms of cooperation, which they call ‘strong reciprocity’ (Gintis et al., 2003). Finally, some evolutionary biologists have used mathematical models to show how the altruistic behaviour of worker insects in raising the offspring of the queen is aimed at ensuring the reproduction of the colony (Nowak et al., 2010).
Nowak (2006) identifies five different ‘rules’ through which cooperation can be nurtured (pictured in Figure 1), in the absence of which the group will succumb to selfish defectors. These are kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection. Kin selection (for its original formulation, see Hamilton, 1964) contends that cooperation has a genetic basis and that its strength wanes the more distantly related the donor and recipient of the altruistic act are. Direct reciprocity is based on a tit-for-tat cooperative strategy of two individuals over repeated interactions. Indirect reciprocity is instead based on reputation: an individual who is known to be helpful is in turn more likely to receive help from others (see Henrich and Henrich, 2007 for an application to the Chaldean community in the United States). Network reciprocity suggests that some individuals interact more often than others, creating network clusters of support. Group-level cooperation emerges when clusters of cooperation outcompete defectors. Finally, group selection translates the idea of endurance by cooperation from the within- to the between-group level, thus suggesting – as mentioned at the beginning of this essay – that more cooperative groups tend to last longer than groups full of defectors (Wilson & Wilson, 2008).
Figure 1: Five rules of cooperation. Blue circles represent cooperators and red circles defectors. Source: own elaboration from Nowak (2006).
These rules, however, are based on mathematical and game-theoretic calculations that say nothing about the mechanisms through which cooperative acts are induced. Moreover, in many instances, cooperation by kin selection or direct reciprocity is simply impossible due to the sheer size of some groups. Here, individuals mathematically cannot be related to everyone in the group, nor can they have direct and repeated interactions with every single person. Likewise, indirect reciprocity based on reputation may only be applicable to a handful of well-known individuals, since in larger groups it becomes more difficult to acquire good information about everyone. None of these rules produces consistent incentives for individuals to cooperate. Hence, there must be other mechanisms that are conducive to cooperation.
Generally, any human group (be it a rebel group, a nation, an organisation, or a commune) faces three main obstacles to cooperation. First, every group presents some degree of variation in its composition. Individuals usually differ in terms of values, interests, and goals. Hence, motivational heterogeneity forces groups to face important collective action problems whereby such diversity of interests and goals needs to be reconciled. Secondly, if individual motivations prevail, shirking is the winning strategy in any kind of social interaction. Defectors dominate cooperators, which will eventually doom the survival of the group. Finally, as groups get bigger, monitoring of behaviour becomes more costly, difficult, and weak.
Today, such problems are often resolved by institutions, being defined as ‘constraints that shape human interaction’ (see North, 1990: 3). Systems of language, law, money, organisations, and traffic conventions are all institutions (Hodgson & Knudsen, 2010: 170; see also Tang, 2011: 3-4). Institutions set rules, reducing transaction costs and uncertainties. However, they are also costly, and many of them constitute a relative novelty in human history. Even today, small or remote groups are devoid of several of these institutions. Then, explaining the longevity of human cooperation entails finding one or more mechanisms that limit the potential to free-ride the efforts of the other individuals in the group.
Figure 2: Human cooperation. Source: iStock/LoveTheWind
A mechanism that can overcome all three obstacles and that has persisted throughout human history is religion. Religion is an institution that is costly and often counterintuitive as a cooperative mechanism, since it requires important cognitive efforts to maintain a network of beliefs (Atran, 2002: 4). Nevertheless, not only has religion developed independently across several groups, but it has also endured the test of time over the past seven millennia. To see how religion works in fostering cooperation and why it works better than other alternatives, below I outline three interrelated processes that help make sense of the persistence of religious communities and practices.
The first process consists of a combination of monitoring and administration of sanctions. In advanced democracies, this is embodied by a strong rule of law with effective enforcement and compliance mechanisms. In dictatorial regimes, instead, monitoring is most often realised in the form of a police state, communication tapping, arrest of dissidents and execution of political rivals. In the absence of such forms of institutional monitoring, other forms of monitoring prevail.
One such form is social monitoring, whereby groups develop cultural norms that lead to the conformity of the group and punish any deviation from the norm. The aforementioned concept of strong reciprocity is based on this idea: norms create conformism, and deviance leads to punishment. However, social monitoring does not avoid situations in which defection strategies are possible because individuals may feel as though they are not being watched. Indeed, several works in psychology show that cues that increase the feeling of being watched (e.g. cameras, mirrors, audience) increase conformity and pro-social tendencies, whereas cues that encourage feelings of being hidden are more conducive to selfishness and cheating (see Norenzayan, 2013: 20-23 for some examples).
Religion (especially Abrahamic religions) circumvents this problem by introducing a new form of monitoring called supernatural monitoring. Supernatural monitoring outsources social monitoring duties to watchful gods with moral concerns, who are free of constraints of time and place. All-seeing and all-powerful deities condemn selfish and divisive behaviours by administering collective punishment, which in turn incentivises individuals to act orderly at all times (Shariff & Norenzayan, 2007). Knowing that supernatural punishment is either indiscriminate or collective, individuals will be more vigilant towards signs of transgression and orderly in their conduct, thus keeping norm violators in line (Atran & Henrich, 2010). This helps the group cohere, uniform, and solve free-rider problems, and may be particularly useful where the group is ethnically and socially heterogeneous (though disagreements exist regarding the causal direction of association between the presence of moralising gods and the complexity of society, see Norenzayan et al., 2016; Whtiehouse et al., 2021).
Figure 3: God the Father and Angel, Guercino (1620). Source: WikiPedia.
A second process that enhances cooperative behaviour is the presence of rituals. Rituals have a triple regulatory function: of emotions, of performance, and of social connection (Hobson et al., 2018). At the emotional level, rituals assuage anxieties and help individuals focus on a particular task, giving them a sense of control and order. Rituals can also help regulate performance: their repetitive nature and the invariable physical movements they entail immerse the observer and the performer alike in the act, thus increasing their belief in the success of the task to be performed. Finally, rituals regulate social connections by engendering synchrony, facilitating automatic imitation, and enhancing the perception of unity and cohesiveness.
Rituals, of course, need not be seen as an exclusively religious act. For instance, sportspeople often have small pre-match rituals to boost their confidence, which can hardly be defined as religious. Rather, rituals signal a commitment to a culture’s most cherished values (Hobson et al., 2018: 273). Religious rituals and taboos are conducive to intra-group cooperation since they provide credible, difficult-to-fake cues of a person’s level of loyalty to the group, which promote trustworthiness and affiliation. (Sosis & Alcorta, 2003: 267).
The importance of these commitments is not only that they are difficult to fake, but also that they are costly in that they involve no immediate pay-off. Thus, by committing to the observance and performance of rituals and taboos, individuals are de facto setting aside their own selfishness for the good of the group. Richard Sosis and his collaborators tested this argument on 19th-century US communes, finding that religious communes were less likely to dissolve because of internal disputes or economic failures compared to secular communes, suggesting a higher degree of ability to solve collective action problems (Sosis, 2000; Sosis & Bressler, 2003). Another such example is suicide bombers, whose costly sacrifice serves the double purpose of letting the group identify cooperators and favouring ‘the cultural linkage, survival, and spread of religious beliefs and rituals’ (Atran & Ginges, 2012: 855).
Figure 4: Navajo Fire Dance, William Robinson Leigh (1920s). Source: Politis
The third and final process is the establishment of clear boundaries. One way to do so is through ‘ethnic markers’ transmitted through social norms and behaviours, such as apparel, language, manners, food preferences and taboos (Henrich & Henrich, 2007). Another way to create such boundaries is by generating divine justifications for morality, distinguishing between what is ‘good’ and ‘true’ on the one hand against what is ‘evil’ and ‘wrong’ on the other. This creates in-groups and out-groups, which reinforce the communal and hive-like nature of the group. Religious boundaries are particularly strong because, unlike political ones, they are immune to falsification. A failed prophecy does not disintegrate the group, but might rather lead to more introspection and commitment (Atran & Henrich, 2010). As the psychologist Jonathan Haidt (2012) puts it, ‘morality binds and blinds.’
In sum, religion addresses all the issues facing cooperation in human groups: monitoring and compliance, collective action problems, and shirking. While religion is certainly not the only mechanism that fosters cooperation – ideology (Sanín & Woods, 2014), ethnicity (Henrich & Henrich, 2007), culture (Boyd & Richerson, 2005), and institutions (Hodgson & Knudsen, 2010) can all be such factors – the present article highlights both its explanatory power as a mechanism of cooperation and its endurance throughout human history. Far from being a ‘time-consuming’, and ‘counterfactual’ enterprise as some evolutionary biologists and philosophers of science such as Dawkins and Dennett would have it, religion is an integral part of human societies, with a clear, if counter-intuitive, evolutionary purpose: the fostering of altruism to strengthen cooperation, and the survival of the group.
Atran, S. (2002). In Gods we Trust. The evolutionary landscape of religion. Oxford: Oxford University Press.
Atran, S., & Ginges, J. (2012). Religious and sacred imperatives in human conflict. Science, 336(6083), 855-857.
Atran, S., & Henrich, J. (2010). The evolution of religion: How cognitive by-products, adaptive learning heuristics, ritual displays, and group competition generate deep commitments to prosocial religions. Biological Theory, 5(1), 18-30.
Boyd, R., & Richerson, P. J. (2005). The origin and evolution of cultures. Oxford: Oxford University Press.
Gintis, H., Bowles, S., Boyd, R., & Fehr, E. (2003). Explaining altruistic behavior in humans. Evolution and Human Behavior, 24(3), 153-172.
Haidt, J. (2012). The righteous mind: Why good people are divided by politics and religion. London: Penguin Books.
Hamilton, W. D. (1964). The genetical evolution of social behaviour. II. Journal of Theoretical Biology, 7(1), 17-52.
Henrich, N., & Henrich, J. P. (2007). Why humans cooperate: A cultural and evolutionary explanation. Oxford: Oxford University Press.
Hobson, N. M., Schroeder, J., Risen, J. L., Xygalatas, D., & Inzlicht, M. (2018). The psychology of rituals: An integrative review and process-based framework. Personality and Social Psychology Review, 22(3), 260-284.
Hodgson, G. M., & Knudsen, T. (2010). Darwin’s conjecture: The search for general principles of social and economic evolution. Chicago, IL: University of Chicago Press.
Norenzayan, A. (2013). Big gods: How religion transformed cooperation and conflict. Princeton, NJ: Princeton University Press.
Norenzayan, A., Shariff, A. F., Gervais, W. M., Willard, A. K., McNamara, R. A., Slingerland, E., & Henrich, J. (2016). The cultural evolution of prosocial religions. Behavioral and Brain Sciences, 39, 1-65.
North, D. C. (1990). Institutions, Institutional Change, and Economic Performance. Cambridge: Cambridge University Press.
Nowak, M. A. (2006). Five rules for the evolution of cooperation. Science, 314(5805), 1560-1563.
Nowak, M. A., Tarnita, C. E., & Wilson, E. O. (2010). The evolution of eusociality. Nature, 466(7310), 1057-1062.
Sanín, F. G., & Wood, E. J. (2014). Ideology in civil war: Instrumental adoption and beyond. Journal of Peace Research, 51(2), 213-226.
Shariff, A. F., & Norenzayan, A. (2007). God is watching you: Priming God concepts increases prosocial behavior in an anonymous economic game. Psychological Science, 18(9), 803-809.
Sosis, R. (2000). Religion and intragroup cooperation: Preliminary results of a comparative analysis of utopian communities. Cross-Cultural Research, 34(1), 70-87.
Sosis, R., & Alcorta, C. (2003). Signaling, solidarity, and the sacred: The evolution of religious behavior. Evolutionary Anthropology: Issues, News, and Reviews: Issues, News, and Reviews, 12(6), 264-274.
Sosis, R., & Bressler, E. R. (2003). Cooperation and commune longevity: A test of the costly signaling theory of religion. Cross-Cultural Research, 37(2), 211-239.
Tang, S. (2011). A general theory of institutional change. London & New York, NY: Routledge.
Whitehouse, H., François, P., Savage, P. E., Hoyer, D., Feeney, K. C., Cioni, E., Purcell, R., Ross, R. M., Larson, J., Baines, J., Haar, B. t., Covey, A., & Turchin, P. (2021). Big Gods did not drive the rise of big societies throughout world history. SocArXiv Preprint. https://doi.org/10.31219/osf.io/mbnvg
Wilson, D. S., & Wilson, E. O. (2007). Rethinking the theoretical foundation of sociobiology. The Quarterly Review of Biology, 82(4), 327-348.
Wilson, D. S., & Wilson, E. O. (2008). Evolution “for the Good of the Group”. American Scientist, 96(5), 380-389.
Figure 1: Five rules of cooperation. Source: own elaboration from Nowak (2006).
Figure 2: Human cooperation. Source: https://hbowie.medium.com/patterns-of-human-cooperation-a73398a4cff7
Figure 3: God the Father and Angel, Guercino (1620). Source: https://it.wikipedia.org/wiki/File:Guercino_(Giovan_Francesco_Barbieri)_-_God_the_Father_and_Angel_-_Google_Art_Project.jpg
Figure 4: Navajo Fire Dance, William Robinson Leigh (1920s). Source: https://politis.com.cy/wp-content/uploads/2019/01/9aXSR8Zh7up2gZTGUrLe.jpg