Evolutionary Explanations of Religion: Adaptation, Group Selection, and Big Gods

التفسيرات التطورية للدين: التكيّف والانتقاء الجماعي وآلهة المراقبة

Summary

The adaptationist program in the cognitive science of religion argues that religion is not merely a cognitive byproduct but a trait selected — culturally, and possibly biologically — for its contribution to large-scale human cooperation. Defenders include David Sloan Wilson, Scott Atran, Ara Norenzayan, and Joseph Henrich. The signature claim is that belief in "big gods" who monitor moral behavior and reward or punish accordingly extends pro-social behavior beyond face-to-face interactions and made possible the formation of large-scale, anonymous, cooperative societies. Within Maslik 4 (Innate Religious), the adaptationist findings are engaged as descriptively powerful but evaluatively inconclusive: they describe how religion has functioned, not whether the religious claims at the heart of religious life are true.

The Two Levels of Evolutionary Argument

Evolutionary arguments about religion operate at two distinct levels, and conflating them produces confusion.

At the biological-evolutionary level, the claim would be that religion-supporting cognitive features were directly selected at the genetic level for survival or reproductive advantage. This is the stronger claim, and it has fewer defenders. Most CSR researchers concede that direct biological selection for religion faces serious obstacles: religion is too recent in evolutionary terms (perhaps a few tens of thousands of years in its developed forms), too variable across cultures, and too easily explained by cultural transmission to require direct biological selection.

At the cultural-evolutionary level, the claim is more modest and more widely accepted: religious systems vary, and those with certain features (moralizing gods, costly rituals, in-group reinforcement) tend to spread and persist because they confer group-level advantages. This is consistent with the byproduct view at the biological level: the cognitive substrate is a byproduct, but cultural-evolutionary processes select among the religious systems that emerge from that substrate.

By the early 2020s, the field had largely converged on this integrationist position: religion originates as a byproduct (biologically) and spreads via cultural-evolutionary selection. The adaptationist program, in this softer form, is about which religious systems thrive and why.

David Sloan Wilson: Group Selection and Darwin's Cathedral

Wilson's Darwin's Cathedral (2002) is the classic adaptationist statement. Wilson argues — controversially at the time, more widely accepted now — that natural selection can operate at the level of groups as well as individuals. When groups whose members cooperate effectively out-compete groups whose members defect, features that promote in-group cooperation can be selected even when they are costly to individual members.

Wilson applies this framework to religion. Religious systems reliably produce features that promote in-group cooperation: shared rituals that build trust, costly displays of commitment that filter out free-riders, moralizing belief systems that internalize group norms, narratives that bind members to a shared identity. On the group-selectionist account, religion is not cognitive flotsam but precisely the kind of trait we would expect multilevel selection to favor.

Wilson develops the argument through case studies (early Christianity, Calvinism in Geneva, the Korean Catholic church) that show how religious systems generated cooperative advantages over their non-religious neighbors. The case studies are illuminating; their generalization to a global theory has been contested.

Scott Atran and the Costly Signaling Account

Scott Atran's In Gods We Trust (2002) develops a complementary argument focused on the role of religious commitment as a costly signal. The challenge in any cooperative system is to distinguish genuine cooperators from free-riders who claim cooperative status without bearing the costs. Costly signals — actions that are expensive to fake — are evolutionary solutions to this problem.

Religion, on Atran's account, generates extraordinarily costly signals: dietary restrictions, fasts, ritual investments, public declarations of belief, sometimes martyrdom. Free-riders can lie about belief but cannot easily fake the long-term behavioral patterns that religious commitment generates. Religious communities, by demanding costly signals, can identify genuine cooperators and exclude defectors.

Atran is less interested than Wilson in group selection as such; his framework can operate at individual level, with religious commitment providing benefits to individuals through inclusion in cooperative communities. The two accounts are complementary rather than competing.

Norenzayan: Big Gods and Large-Scale Cooperation

Ara Norenzayan's Big Gods (2013) consolidates these threads into a specific historical argument. Small-scale societies, where everyone knows everyone, can sustain cooperation through reputation tracking — bad behavior is observed and punished socially. Large-scale societies, where most interactions are with strangers, face a cooperation problem: how do you trust someone whose reputation you cannot check?

Norenzayan argues that belief in "big gods" — powerful, knowing, moralizing, watching — solves this problem. If you believe a cosmic enforcer monitors your behavior and rewards or punishes accordingly, you are more likely to behave cooperatively even with strangers, even when no human is watching. Communities that developed beliefs in big gods would tend to grow larger and more cooperative than communities that did not.

Norenzayan offers cross-cultural and historical evidence: large- scale agricultural societies disproportionately produced moralizing high gods; the timing of big-god emergence correlates with the emergence of large-scale cooperation. The argument has been contested by Whitehouse et al. (2019, in Nature), who argued that the directionality is reversed — large-scale cooperation came first and big gods followed. The debate continues. Norenzayan responded in subsequent work refining the claim.

Joseph Henrich: Cultural Group Selection and the WEIRD World

Henrich's The Secret of Our Success (2015) and The WEIRDest People in the World (2020) extend the framework to the broader case of cultural evolution. Religious institutions are one piece of a larger story: human success is largely cultural rather than genetic, and cultural variants that produce cooperative, innovative, learnable societies tend to spread.

Henrich applies this specifically to the history of the modern West. He argues that medieval Western Christianity, through its marriage and family policies (the so-called Marriage and Family Program), disrupted kin networks in ways that pushed European societies toward more individualistic, more trusting-of-strangers configurations — features that, on his account, underlie what psychology labels "WEIRD" (Western, Educated, Industrialized, Rich, Democratic) cognition. The case is striking; it has been contested by historians, but it represents the most ambitious contemporary application of cultural-evolutionary frameworks to religion.

The Framework's Engagement

The framework engages this body of work with respect. Several observations follow.

First, the adaptationist findings strongly support one descriptive claim of the fiṭra doctrine: that religion has been functional for human life at the deepest social levels, not a parasitic phenomenon to be overcome. The empirical record is clear: large-scale cooperation, complex civilization, sustained moral codes — these are historically intertwined with religion in ways that secular substitutes have not easily replicated.

Second, the adaptationist findings strongly support the cross-cultural prediction of the fiṭra doctrine: religion is reliably and predictably generated by human cognition in social contexts.

Third, the adaptationist findings do not refute the truth claims at the heart of religious life. The genetic fallacy applies here as elsewhere. Showing that religion functions in certain evolutionary or cultural ways does not show that what religion claims is true or false. See the-genetic-fallacy-in-religion-critique.

Fourth, the adaptationist findings come with a subtle hazard for religious self-understanding. If religion is treated as primarily functional — useful for cooperation, useful for social stability — then religious truth claims become incidental to religious use. The framework resists this reduction. Religion is not, on the framework's reading, merely a useful social technology. The functional dimension is real, but it does not exhaust what religion is. (Mature religious self-understanding has always known the danger of using religion instrumentally. Prophetic critique of religious instrumentalism is one of the framework's standing concerns.)

What This Maslik Can and Cannot Establish via Adaptation Theory

The adaptationist research contributes:

Strong empirical evidence that religiosity is a stable, functional, cross-cultural feature of human social life.
Specific mechanisms by which religion has supported large-scale cooperation, in-group cohesion, and moral self-regulation.
A counter-narrative to the simple "religion is decline" story of nineteenth-century secularization: religion has done substantial cooperative work for substantial reaches of human history.

It cannot establish:

The truth of any specific religious claim. Function does not entail veracity.
That religion is reducible to its social function. The framework affirms the social function while resisting the reduction.

Connections to Other Masalik

Maslik 4 (this maslik): companion to cognitive-science-of-religion, which treats the byproduct/ adaptation debate more synthetically.
Maslik 0 (Transversal): the social function of religion bears on religion-and-violence and on questions of religious plurality.
Maslik 3 (Human): the question of whether evolution is explanatorily sufficient for the human reappears here as the question of whether cultural-evolutionary frameworks suffice to explain religious life.

Key Distinctions

Biological evolution of religion (direct genetic selection) vs. cultural evolution of religion (selection among cultural variants)
Adaptation vs. byproduct at the biological level
Group selection vs. individual selection
Big-gods hypothesis (Norenzayan): moralizing gods enabled cooperation
Reverse causation hypothesis (Whitehouse et al. 2019): cooperation enabled big gods
Functional explanation vs. truth-evaluation of religious claims

Major Proponents

David Sloan Wilson — Darwin's Cathedral (2002); group selection and religion
Scott Atran — In Gods We Trust (2002); costly signaling
Ara Norenzayan — Big Gods (2013); moralizing gods and large-scale cooperation
Joseph Henrich — The Secret of Our Success (2015), The WEIRDest People in the World (2020); cultural evolution and religion
Richard Sosis — kibbutz and commune studies on the durability of religious vs. secular cooperative communities
Robert Bellah — Religion in Human Evolution (2011); integrating evolutionary and cultural perspectives

Major Critics

Whitehouse, François, Savage et al. (2019) — Nature paper arguing that complex society preceded moralizing gods, reversing Norenzayan's causal direction
Steven Pinker — The Better Angels of Our Nature (2011); argues for the role of non-religious factors in cooperation expansion
Pascal Boyer — generally favors byproduct over adaptation at the biological level
Talal Asad — critique of the implicit Western category of "religion" used in evolutionary theorizing