# Social structure, cultural selection and the limits of adaptive plasticity: a response to Baumard and André

Alexandra Alvergne

► To cite this version:

Alexandra Alvergne. Social structure, cultural selection and the limits of adaptive plasticity: a response to Baumard and André. Evolution and Human Behavior, 2025, 46 (6), pp.106753. 10.1016/j.evolhumbehav.2025.106753. hal-05397400

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Submitted on 16 Jan 2026

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# Social structure, cultural selection and the limits of adaptive plasticity: a response to Baumard and André

## Abstract

## Introduction

Baumard and André's ecological framework provides important insights to cultural evolution research by demonstrating how many cultural patterns emerge from individual evolved responses to environmental conditions. However, their rejection of transmission-based evolutionary mechanisms may overlook how social structures enable cultural selection to operate and shape cultural dynamics. This commentary argues that understanding when cultural variants succeed through social transmission advantages is needed for mapping the boundaries of human behavioral flexibility.

To debate around cultural evolution dynamics, I distinguish between **broad-sense cultural evolution** (cultural change emerging from individual adaptive responses to environmental conditions, consistent with Baumard and André's framework) and **narrow-sense cultural evolution** (where cultural variants compete based on transmission success rather than individual benefits, following Darwinian principles of variation, inheritance, and selection) (Alvergne, 2023).

Below I illustrate through empirical examples from political communication, health belief systems, and digital social platforms how social structures mediate cultural selection processes, thereby constraining behavioural flexibility to environmental pressures.

Baumard and André (2025) present a compelling challenge to transmission-focused cultural evolution research, arguing that cultural change should be understood as "a descriptive term for historical change, not a mechanism distinct from ecological processes." In this broad-sense view, culture is an ecosystem like any other—shaped by inclusive fitness processes and expressed as extended phenotypes of individuals seeking to maximize genetic replication. They reject the notion that cultural evolution requires separate theoretical foundations.

On the one hand, this perspective resonates with my research on the cultural evolution of modern contraception in rural Ethiopia (Alvergne et al., 2011; Alvergne et al., 2012). When examining the initial 20% increase in contraceptive adoption across four rural villages, early adopters were women experiencing one-year birth intervals—historically associated with poor child survival. We found no clear evidence of biased cultural transmission driving adoption patterns (Alvergne et al., 2011). Instead, contraceptive use enabled women to avoid costly short inter-birth intervals and optimize their reproductive success in a specific ecological context (Alvergne et al., 2012). Early in the diffusion process, the rising frequency of contraceptive users reflects an ecological process: individuals making independent decisions in pursuit of adaptive goals through evolved preferences, without assumptions about imitation or biased transmission. This demonstrates the theoretical value of their approach—allowing for apparently maladaptive fertility limitation to be studied as
individually evolved responses to environmental conditions rather than the outcome of biased cultural transmission. This process has been invoked for explaining the spread of potentially maladaptive outcomes, such as contraception and the demographic transition (P. J. Richerson & Boyd, 2004).

On the other hand, the rejection of transmission-based frameworks represents a missed opportunity to understand dynamics where social structures enable cultural selection to operate as an alternative evolutionary process driving cultural change. When cultural variants succeed through structural embedding and psychological exploitation, they represent a cultural evolutionary process that can constrain human adaptive plasticity.

## Social Structures Constrain Cultural Options Through Biased Transmission

Consider Brexit's "Take Back Control" slogan. It succeeded in spreading not only because it exploited psychological biases (authority bias, confirmation bias, etc.), but also because the campaign created the conditions for cultural biased transmission using information network structures—algorithmic echo chambers, selective media amplification, bot networks (Howard & Kollanyi, 2016). Such processes constrain adaptive information processing and may shed light on cases like Ebbw Vale, Wales' most pro-leave constituency despite having benefited from significant EU investment, and where residents cited immigration concerns despite having one of the country's lowest immigration rates. Notwithstanding the various socio-ecological factors shaping political votes, political campaigns also succeed by exploiting biased information networks that prevent updating based on ecological feedback.

Similarly, research on the persistence of female genital cutting (FGC) among rural Ethiopian communities (Gibson et al., 2025) provides empirical support for cultural selection through biased transmission. Despite low prevalence (6.3%) and participants reporting that fewer than 10% of community members supported the practice, FGC persists through embedding across multiple non-overlapping relationship types—chatting networks, respect relationships, and economic connections. This multi-network embedding enables transmission redundancy where multiple independent pathways ensure continuous reinforcement. Unlike ecological approaches that might predict abandonment due to lack of coordination benefits, the practice may persist because local social structures enable cultural selection where variants succeed through transmission properties.

Inheritance systems provide another illustration of how social structures constrain cultural options. In some matrilineal communities of Northeast India, youngest daughters inherit family property but are expected to remain in their ancestral house to care for relatives. While this rule may have historically increased inclusive fitness, rapid environmental changes can also make it obsolete. Inheritors consistently described feeling "burdened" and "trapped", unable to pursue economic opportunities despite strong preferences for autonomy. The persistence of the philopatry obligation—often with no clear economic benefit compared to migrating—demonstrates how kinship structures constrain cultural options by limiting learning opportunities. Like the Brexit information networks and FGC
relationship networks, kinship networks create transmission advantages for any cultural trait that becomes embedded in kinship rules. This demonstrates how social structures constrain cultural options through conservative transmission mechanisms—kinship systems perpetuate whatever cultural traits become part of them not necessarily because those traits provide kinship or individual advantages, but because the kinship network structure continuously selects for adherence to established rules.

## Contemporary Challenges

The possibility for culture to follow its own course by piggy-backing on social structures has implications for contemporary challenges where cultural variants may succeed primarily through transmission advantages. AI systems and social media platforms represent critical test cases—they shape the transmission of culture by creating the conditions for biased transmission. These platforms are optimized to promote content that exploits psychological biases (outrage, confirmation bias, social validation) through algorithmic amplification, exploiting learning bias toward viral content and conformity bias toward trending opinions. They represent human-built infrastructure that applies cultural selection mechanisms—enabling certain cultural variants to succeed through transmission advantages rather than user benefits, a form of artificial cultural evolution analogous to artificial selection on seeds.

These technologies apply cultural selection through structural-psychological pathways: variable reward schedules exploit dopamine systems, algorithmic echo chambers manipulate confirmation bias, and social validation systems exploit belonging needs. The resulting effects on cognitive flexibility—shortened attention spans, polarized thinking, reduced executive control—represent cultural selection potentially limiting adaptive plasticity through transmission success rather than aligning with individual adaptive goals.

The key take away is that social structures don't just provide environmental contexts; they enable the possibility of entirely different cultural evolutionary dynamics.

## Conclusion

Baumard and André's ecological framework provides essential insights into how cultural change emerges from individual adaptive responses to environmental conditions. Their approach correctly identifies many cases where apparent cultural transmission reflects ecological adaptation, offering theoretical parsimony and empirical clarity.

Yet, abandoning transmission-based frameworks means losing analytical tools for understanding when social structures enable cultural selection to operate as an alternative evolutionary process. Rather than choosing between ecological and transmission approaches, cultural evolution research needs frameworks that can distinguish which ultimate evolutionary process explains specific phenomena—when individual ecological adaptation dominates versus when cultural selection through transmission advantages operates.

This distinction is crucial for mapping the boundaries of human adaptability. In an era of rapid technological and environmental change, understanding when cultural selection might limit adaptive flexibility versus when ecological adaptation enables appropriate responses
may be essential for ensuring that emerging cultural variants enhance rather than constrain
human adaptive capabilities.

References

Alvergne, A., Gibson, M. A., Gurmu, E., & Mace, R. (2011). Social transmission and the spread of modern contraception in rural Ethiopia. *PLoS One*, 6(7), e22515.

Alvergne, A., Lawson, D. W., Clarke, P. M., Gurmu, E., & Mace, R. (2012). Fertility, parental investment, and the early adoption of modern contraception in rural Ethiopia. *American Journal of Human Biology*, 24(6), 731-738.

Baumard, N., & André, J. B. (2025). The ecological approach to culture. *Evolution and Human Behavior*, 46(3), 1066-1086.

Gibson, M., Gurmu, E., Alvergne, A., Van Bavel, H., & Myers, S. (2025). Social clustering of preference for female genital mutilation/cutting in south-central Ethiopia. *Nature Human Behaviour*.

Howard, P. N., & Kollanyi, B. (2016). Bots, #StrongerIn, and #Brexit: Computational propaganda during the UK-EU referendum. *Oxford Internet Institute Research Report*.