Podcast Summary: Conversations With Coleman

Episode: The Evolution of Culture with Joseph Henrich [S2 Ep.20]

Original Release Date: June 26, 2021
Host: Coleman Hughes
Guest: Joseph Henrich, Professor of Human Evolutionary Biology at Harvard University

Overview

This episode explores the profundity and pervasiveness of culture in shaping human evolution, psychology, and society. Coleman Hughes engages with Joseph Henrich to discuss his groundbreaking work on cultural evolution, gene-culture coevolution, the WEIRD (Western, Educated, Industrialized, Rich, Democratic) phenomenon, and how cultural practices can shape human biology and institutions. They delve into practical and sometimes surprising examples—from the necessity of faith in cultural traditions to the neural impact of literacy and dairy consumption—offering a compelling case for why humans owe much of their success and uniqueness to the cumulative legacy of culture.

Key Discussion Points & Insights

1. Henrich's Intellectual Journey & the Limits of Traditional Anthropology

• Background: Henrich describes his disillusionment with anthropology’s explanatory power, leading him toward evolutionary approaches integrating psychology and economics.
  • “Humans are a cultural species heavily reliant on learning from other people, and how that can be integrated into an evolutionary approach.” (03:51)
• Problem in the Field: Traditional models (especially in economics and anthropology) have failed to account for how culture actively shapes preferences and beliefs.

2. Nature of Cultural Evolution & Its Biological Effects

a. Culture Goes Beyond Platitude

• Conservative Assumptions: Many fields ignore or minimize the impact of culture, treating it as separate from or secondary to biological evolution.
• Henrich’s View: Culture is a driving force in shaping not just human behavior but the very structure of our brains and physiology.
  • “Many of our human unique adaptations are actually responses to features constructed through cultural evolution.” (06:08)
  • Example: Literacy physically alters the brain, changing regions related to facial recognition. (09:21–10:10)

b. Non-Trivial Brain Changes

• Acquiring Cultural Practices Physically Changes the Brain:
  • Learning to read thickens the corpus callosum and creates specialized neural circuitry; it also shifts facial recognition processes (10:10).
  • Literacy can actually make individuals slightly worse at facial recognition due to repurposing of neural real estate (10:16).

3. Humans: Cultural Addicts More Than Intellectual Giants

• Comparative Studies: Human children and apes have similar individual cognitive capacities; distinguishing factor is humans’ extraordinary social learning and imitation abilities.
  • “We seem to be cultural learning machines... as adults, we outperform apes in cognitive tasks because we are downloading large amounts of inherited cultural knowledge.” (12:01)
• Vulnerability Without Culture:
  • Stranded explorers often die in environments where hunter-gatherers thrive, lacking knowledge (14:18).
  • “We’re a species that's addicted to culture in ways that other species who have some culture really aren’t.” (13:28)

4. Implicit Wisdom in Cultural Traditions

• Empirical Examples:

  • Manioc (Cassava) Preparation:
    • South American tribes have intricate, time-consuming preparation routines that detoxify cyanide, though practitioners rarely know the reason.
    • Transplanted to Africa, new populations suffered disease due to lack of these traditions (15:33–17:34).
  • Corn and Pellagra:
    • Pre-Columbian Americans used ash in cornmeal to free niacin, preventing pellagra. Europeans missed this, resulting in outbreaks (18:30).

• Cultural Faith:

  • “Humans evolved to put faith in these traditional practices that get passed down... compared to other species, we're much more willing to pay costs, do it the way we've been taught.” (18:30)

5. How Humans Acquire Culture: The 'Who,' 'When,' and 'What'

• Selective Cultural Imitation:
  • Children don’t learn indiscriminately; they seek competent, prestigious, and self-similar individuals, sensitive to context and content (20:46).
  • Bias toward domains like food, animal danger, and social norms.

6. Gene-Culture Coevolution

• Definition: Cultural practices create environmental pressures that drive genetic evolution, and vice versa.
  • “Cooking... allowed our body to reduce the size of our guts... but then we became addicted to and rely on cooking.” (22:30–24:07)
• Human Brains and Childhood:
  • Helplessness and long childhood evolved to facilitate intense cultural learning (24:46).

Controversy and Consensus

• The framework is increasingly accepted; debate lies in specific mechanisms (27:00).

7. Classic Case Study: Lactose Tolerance

• Widespread Misconceptions:
  • Lactose intolerance is actually the historical norm; persistence of lactose digestion into adulthood only appeared in dairy cultures.
  • U.S. government campaigns for milk consumption neglected this, leading to health issues (28:24–30:30).
  • “If we had spent more time trying to get the science right and less time on the politics, we would have done better.” (29:35)

8. Culture as a Driver of Human Evolution

• Against the “End of Genetics, Start of Culture” Myth:
  • “Cultural evolution goes well back into the Paleolithic, deep into our evolutionary history, and has been altering our genetic evolution in important ways.” (31:28)

9. Dog-Human Co-evolution?

• No strong evidence for gene-culture coevolution in humans regarding dogs, though dogs have clearly evolved alongside humans (33:09–35:12).
• Childhood experience likely drives comfort or fear of dogs.

10. Culture and Social Norms Shape Psychology

• Norm Internalization:
  • All societies have shared norms; children rapidly assimilate these, inferring “proper” behavior through frequency and prestige, even without explicit teaching (36:39–37:40).
  • Memorable Experiment: Kids adopt and enforce modeled behaviors on their own and onto puppets (37:40).
  • “Modeling is powerful... but older kids who are the same sex as your kid are even better models.” (39:19)

11. WEIRD vs. Non-WEIRD Cultures

• Acronym: Western, Educated, Industrialized, Rich, Democratic.
• WEIRD Psychology is Unusual:
  • Individualism, analytical thinking, focus on personal aspirations, moral judgment based on intent over outcome, guilt over shame (41:18–43:10).
  • “The populations most commonly studied by psychologists... were often at the extreme ends of the distribution. So they were WEIRD...” (41:04)
• Guilt vs. Shame Cultures:
  • WEIRD societies emphasize guilt (personal standards), whereas many societies root conduct in shame (social norms) (43:28–45:01).
• Self-description Test:
  • WEIRD individuals define themselves in terms of traits; others, by relationships and group memberships (46:09–47:06).
• Variation Within Societies:
  • Significant differences even within nations/regions (47:33).

12. Monogamy and Male Hormones

• Testosterone Studies:
  • Monogamous societies see a decline in male testosterone after marriage/childbirth; polygynous societies do not (48:22–50:28).
  • Cultural norms, not genes, can account for these physiological shifts as evidenced by immigrant and changing societies.

13. Testing Genetic vs. Cultural Causes

• Assimilation Studies:
  • Immigrants’ values shift across generations, supporting cultural over purely genetic causation for psychological traits (51:17).

14. Culture’s Power in Multiethnic Societies

• Persistence of Cultural Differences:
  • Groups (e.g., Protestants vs. Catholics in Prussia, Jews in Europe) maintain distinct cultural traits—including literacy and norms—despite geographic proximity (52:29–57:20).
  • Language, dialect, and endogamy serve as “ethnic boundaries” that maintain separation.

15. Policy Implications & The Collective Brain

• Importance of Culture in Policy:
  • Most policy ignores culture, assuming universal rational actors.
  • Institutional transplants (e.g., U.S. judicial system in Japan) may fail due to local psychologies.
  • “Most policies are psychology blind... they’re culture blind.” (57:47)
• Innovation from Diversity:
  • Diverse, interconnected populations foster recombination of ideas—a prime driver of innovation.
  • Immigration plays a crucial role in national creative capacity (59:35–60:08).

Notable Quotes & Memorable Moments

• “We’re a species that’s addicted to culture in ways that other species who have some culture really aren’t.”
  • Joseph Henrich (13:28)
• “Humans evolved to put faith in these traditional practices ... We’re much more willing to pay costs, do it the way we’ve been taught, than other species are.”
  • Joseph Henrich (18:30)
• “If we had spent more time trying to get the science right and less time on the politics, we would have done better.”
  • Joseph Henrich, on milk campaigns and lactose tolerance (29:35)
• “The populations most commonly studied by psychologists ... were often at the extreme ends of the distribution. So they were WEIRD...”
  • Joseph Henrich (41:04)
• “Most policies are psychology blind ... they’re culture blind.”
  • Joseph Henrich (57:47)

Timestamps for Important Segments

• 03:29 Introduction to Henrich’s academic journey and early dissatisfaction with anthropology
• 05:13–08:25 The science of culture’s impact on biology and psychology
• 09:21–10:16 How literacy reorganizes the brain
• 11:24–14:51 Human intelligence vs. inherited cultural knowledge; role of imitation
• 15:33–19:59 Deep wisdom in seemingly arbitrary tribal traditions (manioc, corn)
• 22:26–26:50 Gene-culture coevolution and childhood as a learning window
• 28:24–30:30 The history and consequences of milk consumption
• 36:39–39:19 Social norms: internalization and the powerful role of modeling
• 41:04–43:10 The WEIRD phenomenon and its psychological implications
• 48:22–50:28 Monogamy, polygamy, and testosterone—cultural impact on biology
• 57:47–60:08 Policy implications and the synergy of collective intelligence

Conclusion

Joseph Henrich’s work provides a powerful lens for understanding human uniqueness, emphasizing that culture is not a veneer on biology but a dynamic evolutionary force shaping who we are—individually, socially, and even physically. This episode offers rich food for thought for anyone interested in how invisible traditions, social learning, and the legacies of our cultural ancestors continue to shape the world today.