Cultural Evolution

Cultural Evolution in Psychology

Prominent Theories of Cultural Evolution

  • Gene-Culture Co-Evolution/Dual Inheritance Theory

  • Cultural Group Selection Theory

  • Cumulative Cultural Evolution/The Ratchet Effect

  • Shared Intentionality

  • Cultural Attraction Theory/Epidemiology of Representations

  • Cultural Niche

  • Network-Based Models

Source: Elizaveta Solomonova, 2026; Van der Bergh, 2018, Human Evolution: Beyond Biology and Culture.

Some of the Most Prominent Cultural Evolution Theories

Dual Inhertiance/Gene-Culture Co-evolution

Dual Inheritance/Gene-Culture Co-Evolution

  • Definition: The theory that genetic and cultural evolution interact with one another.

    • Culture provides selective pressure on genes.

    • Genetics enables cultural features and behaviors.

  • Feedback Loop Example:

    • Adoption of agriculture leads to selection pressures for lactose genes.

  • Principles:

    • Cultural change can be interpreted in Darwinian terms, including:

    • Social learning biases.

    • Survival of certain traits.

  • Niche Construction: Mutual modification between humans and their environments.

    • Example: Farming leads to property rights and advancements such as irrigation.

  • Evolutionary Trajectories: Culture actively shapes evolutionary outcomes rather than passively being a result.

Source: Elizaveta Solomonova, 2026; Whitehead et al., 2019, Nature Communications.

Example: The Obstetrical Dilemma

  • Concept: A tradeoff that highlights the interplay between biology and culture.

    • Narrow pelvis is advantageous for bipedalism.

    • Larger neonatal heads due to increased brain size.

  • Cultural Response:

    • The solution lies in cultural practices.

    • Resulting in:

    • Giving birth to immature infants necessitates an extended childhood.

    • Cooperative child-rearing practices emerge.

    • Development of obstetric practices and technologies (e.g., midwifery).

  • Cultural Niche: Knowledge from collective experiences mitigates the complexities and risks associated with childbirth and extended care requirements for infants.

Source: Elizaveta Solomonova, 2026.

Example: Cooking Hypothesis

  • Researcher: Richard Wrangham.

  • Premise: Cooking food leads to significant physical changes.

    • Results in:

    • Smaller and weaker teeth and jaw muscles.

    • Smaller mouth size and reduced chewing time.

    • Decreased overall gut volume.

    • Shift from fiber fermentation towards digesting cooked food.

    • Enhanced capacity to support larger brains and higher activity levels.

  • Conclusion: Culture (cooking) directly supports physiological changes and adaptations.

Source: Elizaveta Solomonova, 2026.

Example: Lactose Tolerance

  • Observation: Most mammals lose the ability to digest lactose after weaning.

  • Key Point: Lactase persistence is a dominant Mendelian trait seen in certain populations.

    • Common in populations with historical dairy consumption (e.g., European, African, Middle Eastern, South Asian).

    • Virtually absent in other regions.

  • Cultural Influence: The domestication of animals leads to dairy consumption, introducing selection pressures that favor the mutation for lactase persistence.

Source: Elizaveta Solomonova, 2026; Itan et al., 2010.

Cultural Group Selection Theory

  • Overview: Cultural traits can be selected based on group-level dynamics.

  • Implications:

    • Large-scale cooperation and shifting social norms (including behaviors, practices, and religions).

    • Variations in cultural traits among groups become inherited and can persist over time.

    • Different traits can lead to varied levels of success among cultural groups.

Source: Elizaveta Solomonova, 2026; Smith, 2020, Evolutionary Human Sciences.

Ratchet Effect/Cumulative Cultural Evolution

  • Concept: Culture accumulates modifications over generations, akin to a ratchet that prevents backward movement.

  • Mechanism:

    • Unlike other species, humans exhibit the ratchet effect, enhancing cumulative cultural knowledge.

  • Requirements for the Effect:

    • High-fidelity transmission of information.

    • Cooperative sharing of knowledge and skills.

  • Consequences:

    • Leads to increased diversity and sophistication in cultural outputs (art, science, technology).

    • Culture is scaffolded through material artifacts, social organization, and cognitive capabilities.

Source: Elizaveta Solomonova, 2026; reference to Tomasello, 1999 and Heintz, 2013.

Shared Intentionality

  • Researcher: Michael Tomasello.

  • Definition: Intentionality allows for coordinating actions, goals, and mental states with others through shared understanding.

  • Human Capacity:

    • Unique social-cognitive skills that enable joint action and mutual understanding of goals.

    • Joint Intentionality: Working together towards shared goals.

    • Collective Intentionality: Higher level engagement, developing a “cultural common ground” (norms, rules, beliefs).

  • Cultural Ratchet Effect: Communities that engage in collective exploration improve their norms and practices with each generation.

Source: Elizaveta Solomonova, 2026; O’Madagain & Thomasello, 2021.

Cultural Attraction Theory/Epidemiology of Representations

  • Researcher: Dan Sperber.

  • Critical Response: Challenges traditional memetics, which emphasizes high-fidelity replication of cultural practices.

  • Cultural Transmission:

    • Discusses the notion of cultural representations with variation as attractors.

    • Minds have evolved domain-specific biases making certain cultural elements more memorable.

  • Causal Factors: Cognitive, affective, and motivational predispositions create “forces of attraction” in cultural representations.

  • Cultural Mutation: Variation and guided changes in the norms of cultural transmission are possible.

Source: Elizaveta Solomonova, 2026; Buskell, 2017.

The Zone of Latent Solutions

  • Proposal: Understanding how cumulative know-how functions within societies.

  • The “grey zone”: Skills can prime the learning of additional skills (latent cultural traits) fostering emergent functionalities.

  • Cultural Networks:

    • Behaviors and traits can re-invent without direct procedural copying.

    • Bundled behaviors form stable cultural domains (e.g., hunting skills or cooking).

  • Communities: Serve as containers that replicate and evolve bundles of cultural traits.

Source: Elizaveta Solomonova, 2026; Andersson & Tennie, 2023, Nature Humanities and Social Sciences Communications.

Cumulative Cultural Traits and Institutions

  • Mechanism: Interaction between learners and institutions results in the formation and perpetuation of cultural traits.

  • Dynamic Interaction: Traits within learner communities can give rise to institutions that exhibit functions.
    Source: Elizaveta Solomonova, 2026; Andersson & Tennie, 2023.

Network Theory

  • Theory A (Classical):

    • Depicted as a “ladder” where an increase in skills enhances cultural sophistication.

    • Driven by high-fidelity imitation.

  • Theory B (Proposed):

    • Represents a “web” or network image where reinforcement of latent skills occurs.

    • Proto-institutions bundle skills and adapt when groups split, maintaining the skillset across communities.
      Source: Elizaveta Solomonova, 2026; Andersson & Tennie, 2023.

Contemporary Examples of Network Theory

  • Trajectory A:

    • TikTok Dances: Success relies on precise copying and skill acquisition.

    • Food Cultures: Knowledge facilitated through skill-learning and recipe adherence.

    • Coding: Skills transmitted via tutorials and formal education.

  • Trajectory B:

    • TikTok Dances: Variation and improvisation are essential; relies on existing skills for successful execution.

    • Food Cultures: Persistence through experimentation rather than strict recipe adherence.

    • Coding: Skills dynamically circulate with evolving goals, allowing for reinvention.
      Source: Elizaveta Solomonova, 2026.

Cultural Traits: Open-Endedness

  • Characteristics:

    • Cultural evolution involves cumulative changes and stability but isn't exclusive to humans.

  • Distinctiveness: Humans exhibit a greater capacity for heritable variation, allowing for the exploitation of new phenomena.

  • Adaptability: Traits can be recombined to address novel challenges.

  • Avoidance of Local Optima: Unlike other species, humans do not limit themselves to immediate best solutions.
    Source: Elizaveta Solomonova, 2026; Morgan & Feldman, 2024, Nature Human Behaviour.

Cultural Niche: Boyd's Perspective

  • Claim: Human success cannot be solely attributed to intelligence.

  • Cognitive Niche: Humans utilize “improvisational intelligence” to adapt culturally.

  • Cultural Niche: Emphasizes reliance on culturally transmitted skills and information for adaptation.

  • Gradual Improvement: It reinforces the necessity of cultural understanding alongside physical laws for population-level adaptations.

  • Counter to Dualism: Advocates that culture is intrinsically intertwined with human biology.
    Source: Elizaveta Solomonova, 2026.

Cultural Niche: Selective Social Learning

  • Concept: Social learning functions as “information scrounging”, providing ease of access to learned information from others.

  • Evolution of Behavior: Humans have evolved to depend on societal imitation, particularly when learning individually becomes burdensome.

  • Understanding not Necessary: Knowledge of effectiveness suffices, even if the mechanics remain unclear.
    Source: Elizaveta Solomonova, 2026.

Commonalities Between Theories of Cultural Evolution

  • Dynamic Cultures: Cultures operate under evolutionary processes.

  • Key Component: Social learning is central for cultural transmission.

  • Skills: This transmission is facilitated through cognitive abilities including mindreading and language.

  • Role of Cooperation: Distinctive sociality in humans enables cultural evolution.

  • Cognitive Interaction: Cognition closely intertwines with culture; understanding one necessitates consideration of the other.
    Source: Elizaveta Solomonova, 2026.

Differences Between Theories of Cultural Evolution

  • Genetic Variation: The extent to which genetic factors explain similarities and differences within groups.

  • Units of Transmission: Differentiation between individual and group levels of trait transmission.

  • Fidelity of Transmission: Variability in how accurately cultural practices are transmitted.

    • E.g., ratchet theory correlates high-fidelity learning with better skills versus variation-focused theories that prioritize the essence of skills.

  • Focus on Aspects: Each theory emphasizes different phenomena within cultural evolution.
    *Source: Elizaveta Solomonova, 2026.