Tag Archives: cultural complexity

Cultural Evolution – Chapter in Handbook of Evolutionary Psychology, 2nd Edition

Maciek Chudek, Joe Henrich, and I wrote an introduction to Cultural Evolution in the most recent Handbook of Evolutionary Psychology, 2nd edition – edited by David Buss.

The chapter provides a brief overview of the science of cultural evolution, including its psychological foundations and implications. We discuss how humans evolved a second-line of inheritance, crossing the threshold into a world of cumulative culture. We begin by asking how culture can evolve, dispelling the mythical requirement of discrete genes and exact replication.

Evolutionary adaptation has three basic requirements: (1) individuals vary, (2) this variability is heritable (information transmission occurs), and (3) some variants are more likely to survive and spread than others. Genes have these characteristics so they evolve and adaptive. Culture also meets all three requirements, but in different ways. Like bacterial genes, cultural information spreads horizontally and need not be limited to parental transmission to offspring.

We discuss the evolution of our capacity for culture, asking how and when capacities for culture will evolve (when is cultural learning genetically adaptive).

The answer: culture is adaptive when asocial learning is hard and environments fluctuate a lot, but not too much.

We also outline the evolution of some of our social learning biases (a large part of the third requirement of an evolutionary system):

  1. Who we learn from (e.g. skilled, successful, and prestigious models; conformist transmission)
  2. What moderates these choices (e.g. self-similarity, age, sex, ethnicity; Credibility Enhancing Displays, CREDs).
  3. Some examples in the real world, such as the social spread of suicides (Werther effect) and literally learning better from same-sex and same-race instructors.
  4. Content biases on what to learn: e.g.  animals and plants, dangers, fire, reputation, social norms, and social groupings.

Cultural evolution shapes the beliefs and behaviors of groups so that they come adapted to the local environment (including culture) over time, shaping preferences and psychology.

Turning to the population-level, we explain why sociality influences cultural complexity (larger, more interconnected populations have more terms and technologies), how cultural evolution can lead to maladaptive behavior, and how intergroup competition can help eliminate these maladaptive behaviors, briefly discussing the viability of cultural-group selection.

Finally, we discuss how genes can adapt to culture: culture-gene coevolution and how this process may have led to the rapid expansion of the human brain.

Cultural Brain Hypothesis, Cultural Evolution & Human Social Networks at Stanford University, California

This week I visited Stanford University, California. Jamie Holland Jones invited me to present my research on human evolution, cultural evolution, and social networks at the Stanford Anthropology Colloquium Series. I presented three related projects:

The Cultural Brain Hypothesis (in prep; co-authored with Maciek Chudek and Joe Henrich), describes the evolution of large brains and parsimoniously explains several empirical relationships between brain size, group size, social learning, mating structures, culture, and the juvenile period. The model also describes the selection pressures that may have led humans into the realm of cumulative cultural evolution, further driving up the human brain size.

Sociality Influences Cultural Complexity (2014; co-authored with Ben Shulman, Vlad Vasilescu, and Joe Henrich) on the relationship between sociality and cultural complexity.

Cultural Dispositions, Social Networks, and the Dynamics of Social Influence: Implications for Public Opinion and Cultural Change (under review; co-authored with Mark Schaller) describes a mechanism through which realistic human social network structures can emerge and the implications of these mechanisms for cross-cultural differences in cultural transmission and innovation.

Cultural Evolution and How Sociality Influences Cultural Complexity at University of Queensland, Australia

This week I visited my alma mater, The University of Queensland, Australia. Mark Nielsen and Thomas Suddendorf (both of whom I was lucky enough to take classes with as an undergraduate) invited me to present my paper on how “Sociality Influences Cultural Complexity” and my chapter on Cultural Evolution. The chapter, coauthored with Maciek Chudek and Joe Henrich, will be appearing in the new Handbook of Evolutionary Psychology. I presented the research to the Evolutionary Psychology group, which I took great pleasure in, being a member of the group as an undergraduate.

While at Queensland, I also caught up with my Honours supervisor, Penny Sanderson, and my former colleagues, Morgan Tear and Matt Thompson.

Overconfidence at Hokkaido University, Sapporo, Japan

I spent the last week at Hokkaido University in Sapporo, Japan. I was invited to present my paper on how “Sociality Influences Cultural Complexity“. I also helped set up an experiment that Joe HenrichSteve Heine, and I are running in collaboration with Tatsuya Kameda and Wataru Toyokawa. We previously collected data in Hong Kong in collaboration with Takeshi Hamamura.

Hokkaido University, Sapporo, Japan 

Muthukrishna, M., Shulman, B. W., Vasilescu, V., & Henrich, J. (2013). Sociality influences cultural complexity. Proceedings of the Royal Society B: Biological Sciences, 281(1774).

Sociality Influences Cultural Complexity

Proceedings of the Royal Society B: Biological Sciences published my paper with Ben W. Shulman, Vlad Vasilescu, and Joe Henrich showing that sociality influences cultural complexity. Across two experiments, we show that access to more people (1) increases cultural complexity, allowing for cumulative cultural evolution and (2) reduces the loss of cultural knowledge and skill. We found that students paid most attention to the most capable of their mentors, but also drew inspiration from the others, suggesting that the benefit of greater interconnectivity is twofold: you have access to the best people and information, but are also able to recombine knowledge from a greater variety of people.

Nature News, Kurzweil AI, CKNW, and GlobalTV were among the media outlets that featured the research. I explain the research to Philip Till at CKNW below.


Experiment 1 showing difference between access to models on cultural complexity.

Muthukrishna, M., Shulman, B. W., Vasilescu, V., & Henrich, J. (2013). Sociality influences cultural complexity. Proceedings of the Royal Society B: Biological Sciences, 281(1774). [Download]