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Max Denis

June 7th, 2021

Cultural Evolution: The Success of the Religious Group Structure


Estimated reading time: 5 minutes

Max Denis

June 7th, 2021

Cultural Evolution: The Success of the Religious Group Structure


Estimated reading time: 5 minutes

Some of the most powerful groups in the world are religious ones. Why? In this post, Max Denis (studying BSc Psychological and Behavioural Science) describes how religious groups have passed down ideologies, rituals and practices for thousands of years by creating a large-scale culture of cooperation.

If asked what group you belong to, you’d probably have a choice between several answers. From the workplace to your social circles, and your ethnicity, you’ll feature in groups from all realms of life. We rarely exist as isolated individuals.

Our early ancestors realised that joining a group has many advantages e.g., more resource accumulation, greater safety from predators and more stable opportunities for reproduction. Joining a group presented a better chance for survival (Wilson, 2015). So, naturally, most people joined groups. But not everyone survived.

The Ingredients for a Successful Group

Historically, some groups held characteristics which allowed them to function in better ways than others. Each group has a ‘culture’ – a set of norms, practices and tool kits shared by members of the group. The groups with ‘cultures’ that best promoted in-group cooperation, had better chances of survival and successful reproduction – this is the mechanism of ‘cultural group selection’ (Henrich & Muthukrishna, 2021).

As human culture advanced, practices of agriculture were adopted as opposed to relying solely on hunting and gathering. Agricultural practice worked better when group sizes were bigger. Here, a problem emerges. When groups get bigger, they struggle to keep connected, which means they struggle to keep cooperation (Dunbar, 1993). Bigger groups present bigger risks. Selfish individuals might take advantage of those working for the collective good, for their own personal gain (Sosis & Alcorta, 2003).

The key is to establish a group culture which reduces the risk of free-riders while promoting large scale cooperation. This is easier said than done. Most groups became infiltrated by free-riders which led to their collapse. But others managed to overcome this problem and ensured cooperation on a large-scale. Why did some groups crumble while others have a legacy that lives on today?

How Religion Promoted Cooperation within Groups

Some of the biggest and most powerful groups are undoubtedly religious ones. It is estimated that religious groups make up 84% of the world’s population (Wormald, 2015)! These groups have carried ideologies, rituals and practices for thousands of years through hundreds of generations. By what mechanisms did religion allow groups to become cooperative?

Belief in God Inhibits Selfishness

Masjid NabawiIt seems an unlikely coincidence that the most popular religions today e.g., Christianity, Islam and Judaism, are all governed by faith in a moralistic monotheistic god. Has belief in God protected large-scale groups from the free-rider problem?

Religions highlight rules that believers ought to follow for the good of the group e.g., “thou shalt not kill”, and make clear that a supernatural being is observing them to monitor this behaviour. Non-compliance with these rules puts the individual at risk of an eternal suffering in some kind of Hell. Quite the disincentive.

The feeling of being watched by others certainly affects our behaviour. We can all recall times where we’ve behaved in a manner, different to if others were in our presence. Does belief that God is watching you have the same effect? It turns out, yes.

Replicated experimental data shows that the awareness of God does indeed select for cooperative behaviour. Researchers found that when believers were implicitly reminded of God, they showed greater generosity in an economic game allocating funds to a stranger (Shariff & Norenzayan, 2007) (Shariff et al., 2016). It is theorised that implicit signals of religious figures reminded believers they were being watched by their god and that they ought to behave in a moral way. Belief in God warrants a threat of supernatural punishment which not only inhibits selfishness but promotes generosity – a core value necessary for group cooperation and survival in the long-run.

Beyond generosity, having shared commitments to belief in God makes members of the group more likely to care for unwell group members, help rebuild a member’s shelter destroyed by a storm, or attack an enemy group (those who lack the beliefs in God) (Stark, 1997). What becomes apparent, is that belief in God binds group members together. It allows them to work cooperatively increasing their likelihood of survival compared to non-religious groups. It also increases out-group competitiveness e.g., religious groups (who are more cooperative) will be more effective in warfare versus non-cooperative ones (Henrich, 2015).

The Costs of Belief in God

There still remains the problem of scaling up a cooperative group without unknowingly admitting free-riders. How did religions solve this?

To be part of any religion requires a relatively high level of commitment with evidential proof. Believers need to prove their affiliation to the group by bearing certain costs. These costs must be high enough to discourage free-riders and difficult to fake, e.g., male circumcision, is a common way believers proved their dedication to the group by undergoing an irreversible and historically painful procedure (Whiting et al., 1958).

It’s been found that the more costs a group has e.g., restrictions on sex, food, taboos etc., the longer the group will survive (Sosis & Bressler, 2003). Greater costs reflect a lower chance of free-riders penetrating the group. It follows, then, that a lower presence of free-riders allows the group to flourish cooperatively for longer.

Seeing fellow members undertake these costs reinforces the belief in God, promoting in-group cooperation and out-group competitiveness. Importantly, belief in God fosters group cooperation in a more efficient way than groups lacking this shared belief system (Henrich, 2009). This means in-group bonds were formed faster where the group had to the bear the same costs in the name of God. This gave the religious group an all-important survival advantage.

Establishing barriers to entry for religious groups prevents selfish individuals slipping through the cracks and taking advantage of a cooperative group structure. Shared belief in God forms the necessary affiliations between group members to sustain cooperation. God’s ‘all-seeing’ nature maintains moral behaviour by threat of supernatural punishment (Johnson, et al., 2003).

Through these mechanisms, religious groups have established long-running sustainable forms of cooperation. This has allowed for their survival and reproduction through countless generations – making religious groups some of the most successful in all of history.


  • The views expressed in this post are of the author and not the Department of Psychological and Behavioural Science or LSE.
  • This blog post was originally written as part of PB101: Foundations of Psychological Science, a compulsory course on the BSc Psychological and Behavioural Science programme in the Department of Psychological and Behavioural Science at LSE. It has been published with the permission of the author. Visit the PBS website for more information on studying in the department:
  • Feature photo by thom masat on Unsplash.
  • Image used within the post by Adli Wahid on Unsplash.


Wilson, D. S. (2015). Does altruism exist?: culture, genes, and the welfare of others. Yale University Press.

Henrich, J., & Muthukrishna, M. (2021). The origins and psychology of human cooperation. Annual Review of Psychology, 72, 207-240.

Dunbar, R. I. (1993). Coevolution of neocortical size, group size and language in humans. Behavioral and brain sciences, 16(4), 681-694.

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.

Wormald, B. (2015). Religious Composition by Country, 2010-2050. Pew Research Center’s Religion & Public Life Project.

Shariff, A. F., & Norenzayan, A. (2007). God Is Watching You: Priming God Concepts Increases Prosocial Behavior in an Anonymous Economic Game. Psychological Science18(9), 803–809.

Shariff, A. F., Willard, A. K., Andersen, T., & Norenzayan, A. (2016). Religious Priming: A Meta-Analysis With a Focus on Prosociality. Personality and Social Psychology Review, 20(1), 27–48.

Stark, R. (1997). The Rise of Christianity: How the Obscure, Marginal Jesus Movement Became the Dominant Religious Force in the Western World in a Few Centuries. New York: Harper Collins.

Henrich, J. (2015). The secret of our success. Princeton University press.

Whiting, J. W., Kluckhohn, R., & Anthony, A. (1958). The function of male initiation ceremonies at puberty. Readings in social psychology, 359-370.

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.

Henrich, J. (2009). The evolution of costly displays, cooperation and religion: Credibility enhancing displays and their implications for cultural evolution. Evolution and human behavior, 30(4), 244-260.

Johnson, D. D., Stopka, P., & Knights, S. (2003). The puzzle of human cooperation. Nature, 421(6926), 911-912.


About the author

Max Denis

Max is an undergraduate student studying Psychological and Behavioural Science at the LSE. He is from London and has a rich interest in organisational decision making. Looking forward, Max aims to apply the latest behavioural insights learnt during his studies into fields of marketing and HR in the corporate world.

Posted In: BSc Psychological and Behavioural Science | Cultural Evolution | Cultural psychology | PB101 Foundations of Psychological Science

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