Tag Archives: research

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Center for Advanced Study in the Behavioral Sciences at Stanford University, CA

I spent the weekend at a productive interdisciplinary workshop on “Religion, Ritual, Conflict, and Cooperation: Archaeological and Historical Approaches” at the Center for Advanced Study in the Behavioral Sciences (CASBS) at Stanford University. CASBS is located on the top of one of the beautiful hills around Stanford.

We discussed the challenges and successes in inferring religious belief and practice from the archeological and historical record  and new theoretical models and tools for exploring religious history, including the Database of Religious History (DRH).

Other attendees included:

David Carballo (Boston University)
Chris Carleton (Simon Fraser University)
Jesse Chapman (Stanford University)
Mark Csikszentmihalyi (UC Berkeley)
Megan Daniels (Stanford University)
Russell Gray (Director, Max Planck Institute for the History and the Sciences)
Conn Herriott (University of Jerusalem)
Ian Hodder (Stanford University)
Joseph Manning (Yale University)
Jessica McCutcheon (University of British Columbia)
Frances Morphy (Australian National University)
Howard Morphy (Australian National University)
Ian Morris (Stanford University)
Ara Norenzayan (University of British Columbia)
Beate Pongratz-Leisten (NYU)
Neil Price (Uppsala)
Benjamin Purzycki (University of British Columbia)
Ben Raffield (Simon Fraser University)
Katrinka Reinhart (Stanford University)
Celia Schultz (University of Michigan)
Edward Slingerland (University of British Columbia)
Charles Stanish (UCLA)
Brenton Sullivan (Colgate College)
Edward Swenson (University of Toronto)
Robban Toleno (University of British Columbia)
Robyn Walsh (University of Miami)
Joseph Watts (University of Auckland)

ehb

The When and Who of Social Learning and Conformist Transmission

Tom Morgan, Joe Henrich and I recently published a paper on the “The When and Who of Social Learning and Conformist Transmission” in Evolution and Human Behavior.

Conformist transmission is a type of frequency dependent social learning
strategy in which individuals are disproportionately inclined to copy the most common trait in their sample of the population (e.g. individuals have a 90% probability of copying a trait that 60% of people possess). The bias is particularly important, because it tends to homogenize behavior within groups increasing between group differences relative to within group differences.

Our three key findings across two experiments were:

  1. Substantial amounts of conformist transmission. We found substantial reliance on conformist biased social learning, with only 3% and 9% (or 15%) showing no bias in Experiments 1 and 2, respectively.
  2. Increased social learning and stronger conformist bias as the number of options increased. Both the amount of social learning and the strength of conformist biases increased as the number of options increased (i.e. 60% of people wearing black shirts is more persuasive in a world of black, red, blue, yellow, and white shirt colors than in a world of only black shirts and white shirts). These results mean that all prior experiments have underestimated reliance on social learning and the strength of conformist transmission, since all use only 2 options.
  3. IQ predicts both social learning and the strength of the conformist bias. IQ predicts less social learning, but has a U-shaped relationship to the strength of the conformist bias. These results suggest that higher IQ individuals are strategically using social learning (using it less, but with a stronger conformist bias when they choose to use other information).

For a list and discussion of all key findings, see the Discussion section of the paper.

Selected Media Coverage

CBC Radio “The 180” Interview

Global TV News Interview

Fast Company

Natal, Brazil

Human Behavior and Evolution Society Conference in Natal, Brazil

I attended the 26th Human Behavior and Evolution Society (HBES) Conference in Natal, Brazil. I gave a talk on the Cultural Brain Hypothesis and the Cumulative Cultural Brain Hypothesis.

The paper (in prep), co-authored with Maciek Chudek and Joe Henrich, describes an evolutionary model of the evolution of 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.

St Andrews

Cultural Brain Hypothesis and Cumulative Cultural Brain Hypothesis at St Andrews, Scotland

This week I visited the University of St Andrews, Scotland. Kevin Laland invited me to present my paper (in prep) on the Cultural Brain Hypothesis and the Cumulative Cultural Brain Hypothesis. The paper, co-authored with Maciek Chudek and Joe Henrich, describes an evolutionary model of the evolution of 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. I presented the research to Kevin’s lab and to Andy Whiten’s lab. I will also be presenting the paper early next month at the 26th Annual Meeting of Human Behavior and Evolution Society (HBES) in Natal, Brazil.

While at St Andrew’s, I met with Andy Whiten, Luke Rendell, Kate Cross, Ana NavarreteDaniel Cownden, Daniel van der Post, Cara Evans, James Ounsley, Andrew Whalen, Lewis Dean, and Murillo Pagnotta, among others. Kevin is currently on sabbatical at the University of Cambridge.

brisbane

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.

Sapporo, Japan

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).
procb

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.

Experiment1

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]