handbook_evolutionary_psychology

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.

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

Erfurt, Germany

Database of Religious History at IAHR 2015 in Erfurt, Germany

This week the Database of Religious History (DRH) Team presented the DRH in a panel at the XXI World Congress of the International Association for the History of Religions in Erfurt, Germany. The panel, along with an exhibition booth continues our publicity and recruitment efforts. Our presentation was similar to our most recent efforts at Cultural Evolution of Religion Research Consortium Meeting in Montreal, Canada:

Edward Slingerland (Project Director) presented an overview of the strategy and future directions of the project.
Brenton Sullivan (Managing Editor) discussed how the project relates to other humanities databases and religious studies in general.
Frederick Tappenden (Regional Editor) discussed how our terminology, in particular, “religious group”, has evolved through feedback from historians and religious scholars.
Carson Logan (Technical Manager) updated the audience on changes in usability.

As Technical Director of the project, I discussed the technical design and updated the audience on the development of the project, including some exciting new features  (e.g. the ability to challenge answers).

Read more about our efforts to publicize the database here.

Montreal Skyline

Database of Religious History at the Cultural Evolution of Religion Research Consortium Meeting in Montreal, Canada

This weekend the Database of Religious History (DRH) Team presented the DRH at the Cultural Evolution of Religion Research Consortium (CERC) Plenary Meeting at McGill University in Montreal, Canada. Our goal was to update the broader CERC team on our achievements for the year and to attract more historians and religious studies scholars to the project.

Edward Slingerland (Project Director) presented an overview of the strategy and future directions of the project.
Brenton Sullivan (Managing Editor) discussed how the project relates to other humanities databases and religious studies in general.
Frederick Tappenden (Regional Editor) discussed how our terminology, in particular, “religious group”, has evolved through feedback from historians and religious scholars.
Jessica McCutcheon (Managing Editor) remotely updated the audience on recruitment and changes in usability.

As Technical Director of the project, I discussed the technical design and updated the audience on the development of the project, including some exciting new features  (e.g. the ability to challenge answers).

Carol Ember, President of the Human Relations Area Files (HRAF) at Yale University then responded to our panel with useful comments and suggestions.

You can read more about our efforts to publicize the database here.

Database Visualization

Database of Religious History at Department of Statistics, University of British Columbia, Canada

I was invited to present the Database of Religious History at the Department of Statistics Seminar Series. Nancy Heckman,  Head of the Statistics Department, watched our award winning video on the database and was interested in possible connections with researchers in statistics. I presented some of the technical design aspects of the database as well as our statistical approach to analyzing the data.

Afterwards, I had lunch with several members of the department, including Nancy Heckman, Ruben Zamar, Cindy Greenwood, and Davor Cubranic, as well as with Andrew Trites, Director of the Marine Mammal Research Unit and North Pacific Universities Marine Mammal Research Consortium and Fisheries Centre Co-Director. I hope that collaborations with the Department of Statistics will allow us to find new ways to share and analyze our rapidly growing data.

Human Evolution and Social Change, Arizona State University

Cultural Brain Hypothesis at Arizona State University, Arizona

This week I visited Arizona State University, Arizona. Rob Boyd and Joan Silk invited me to present my research on the Cultural Brain Hypothesis at the Evolution of Social Complexity Colloquium Series, sponsored by the School of Human Evolution and Social Change, the Institute of Human Origins and the Consortium for Biosocial Complex Systems.

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.

The School of Human Evolution and Social Change and the Institute of Human Origins has an exceptional group of human evolutionary researchers. While at Arizona State University, I caught up with Rob BoydJoan SilkKim HillSarah MathewCharles Perreault, Michelle Kline, and Matt Gervais.

Stanford University

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.

storytellers

SSHRC Impact Awards Talk in Ottawa, Ontario

As a Top 5 winner of the Social Sciences and Humanities Research Council of Canada’s (SSHRC) Research for a Better Life: The Storytellers challenge, I was invited to present our research on the Database of Religious History at the SSHRC Impact Awards ceremony in Ottawa, Ontario.

It was an honor to meet the the Governor General of Canada, His Excellency the Right Honourable David Lloyd Johnston, SSHRC’s Executive Vice-President and Chief Operating Officer, Ted Hewitt, SSHRC’s Associate Vice-President, Future Challenges, Ursula Gobel (who I previously met at SSHRC Congress), CBC host of Ideas, Paul Kennedy, and the winners of the SSHRC Impact AwardsBeverley DiamondThomas LemieuxNico TrocméWendy Craig, and Kirk Luther.

You can watch my talk below:

The Database of Religious History has been featured in several places, including canada.ca. See my previous News post for more details.

SSHRC Impact Awards

Top Row (Left to Right): Robin MacEwan, Michael Muthukrishna, James O’Callaghan, Ted Hewitt (Executive Vice President, SSHRC), Hon. David Johnston, Ursula Gobel (Associate Vice-President, Future Challenges, SSHRC), Vineeth Sekharan, Marylynn Steckley

Bottom Row (Left to Right): Thomas Lemiux (Insight Award), Nico Trocmé (Connection Award), Beverley Diamond (Gold Medal), Wendy Craig (Partnership Award), Kirk Luther (Talent Award)