This year marks the 150th anniversary of Charles Darwin’s Descent of Man. As part of the celebration, the Center for the Dynamics of Social Complexity (DySoc) organized a series as Outreach for the Cultural Evolution Society: Celebrating the 150th anniversary of the The Descent of Man (http://www.dysoc.org/dom_webinars). I presented the most up-to-date version of the “Cultural Brain Hypothesis, Collective Brains, and the Evolution of Intelligence”. You can watch the talk below:
Today’s episode is a conversation with Dr. Michael Muthukrishna, an Associate Professor of Economic Psychology at the London School of Economics.
Michael’s research takes on a suite of topics that all start from a single big question: Why are we so different from other animals? Part of the answer has to do with our neural hardware. There’s no question we’ve got big brains—and Michael has some cool things to say about why they may have gotten so big. But Michael is just as focused on our cultural software—the tools and ideas we develop, tweak, share, and accumulate over time. You might say he’s more impressed by our collective brains than by our individual brains. To study all this, Michael builds formal theories and computational models; he runs experiments; and he constructs and analyzes huge databases.
We cover a lot of ground in this episode. We talk about the finding that the size and interconnectedness of a social group affects the cultural skills that group can develop and maintain. We consider what actually powers innovation (hint: it’s not lone geniuses). We discuss how diversity is a bit double-edged and why psychology needs to become a historical science. And that, my friends, is hardly all—we also touch on cetaceans, religious history, and spinning plates.
I’ve been hoping to have Michael on the show for months now. His work is deeply theoretical, advancing the basic science of what it means to be human. But it’s also engaged with important practical issues—issues like corruption and cultural diversity. Without further ado, here’s my conversation with Dr. Michael Muthukrishna. Enjoy!
A transcript of this show will be available soon.
Notes and links
4:30 – An introduction to “dual inheritance theory.”
11:00 – A 2013 paper by Dr. Muthukrishna and colleagues about the relationship between sociality and cultural complexity.
12:15 – A paper on the loss of cultural tools and traditions in the Tasmanian case.
21:20 – A 2016 paper by Dr. Muthukrishna and Joseph Henrich on innovation and the collective brain.
28:30 – The original paper on the notion of cultural “tightness” and “looseness.”
30:20 – A recent short piece by Dr. Muthukrishna on the paradox of diversity.
34:50 – A 2019 popular piece of mine on the phenomenon of “global WEIRDing.”
42:30 – A paper about the significance of Luria’s work on abstract reasoning in Uzbekistan.
50:26 – A paper on the “cultural brain hypothesis,” the subject of Dr. Muthukrishna’s dissertation.
51:00 – A paper on brains as fundamentally “expensive.”
58:00 – Boyd & Richardson, mentioned here, have authored a number of highly influential books. The first of these was Culture and the Evolutionary Process.
59:35 – A 2015 paper on head size and emergency birth interventions.
1:01:20 – The stylized model we mention here is discussed and illustrated in this lecture from the 2020 Diverse Intelligences Summer Institute.
1:03:15 – The paper by Dr. Muthukrishna and colleagues on cetacean brains and culture.
1:11:38 – The paper by Dr. Muthukrishna and colleagues on ‘Psychology as a Historical Science.’
1:14:00 – The 2020 paper by Dr. Muthukrishna and colleagues introducing a tool for the measurement of cultural distance.
1:20:20 – Dr. Muthukrishna is part of the team behind the Database of Religious History.
1:24:25 – The paper by Dr. Muthukrishna and Joe Henrich on ‘The Origins and Psychology of Human Cooperation.’
Dr. Muthukrishna’s end-of-show reading recommendations:
Matt Ridley, How Innovation Works
Matthew Syed, Rebel Ideas
You can keep up with Dr. Muthukrishna’s work at his personal website and on Twitter (@mmuthukrishna).
Many Minds is a project of the Diverse Intelligences Summer Institute (DISI) (https://www.diverseintelligencessummer.com/), which is made possible by a generous grant from the Templeton World Charity Foundation to UCLA. It is hosted and produced by Kensy Cooperrider, with creative support from DISI Directors Erica Cartmill and Jacob Foster, and Associate Director Hilda Loury. Our artwork is by Ben Oldroyd (https://www.mayhilldesigns.co.uk/). Our transcripts are created by Sarah Dopierala (https://sarahdopierala.wordpress.com/).
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I spent the last few days at the Templeton World Charity Foundation (TWCF) Grantee Meeting at the Diverse Intelligences Summer Institute at the University of St Andrews, Scotland. This was my second time attending the meeting and I enjoyed once again discussing the challenges of understanding intelligence (and its implications) with an amazingly diverse and interdisciplinary group of brilliant scholars.
I spent the weekend at a workshop on Life History and Learning at UC Berkeley, organized by Alison Gopnik. I presented the “Cultural Brain Hypothesis and Cumulative Cultural Brain Hypothesis”, which was recently published in PLOS Computational Biology (see here for discussion).
It was a small workshop, which made for some wonderful discussions with:
Sarah Blaffer Hrdy (UC Davis)
Willem Frankenhuis (Radboud University)
Michael Gurven (UC Santa Barbara)
Kristen Hawkes (University of Utah)
Celeste Kidd (UC Berkeley)
Julie Morand-Ferron (University of Ottawa)
Thomas Morgan (Arizona State University)
Susan Perry (UCLA)
Pete Richerson (UC Davis)
Mike Tomasello (Duke)
Natalie Uomini (Max Planck Institute for the Science of Human History)
Last week, my paper with Kieran Fox and Susanne Shultz was published in Nature Ecology and Evolution. The paper was a multiyear project, which consisted of countless hours spent poring through marine mammal literature to create the most comprehensive database of cetacean physiology, social structure, life history, and behavior to date. We then used this database to test some of the predictions of the Social Brain and Cultural Brain Hypotheses. Some of the confirmations of these predictions are shown in Figure 3 of the paper below.
Cetaceans represent a great test for the Social Brain and Cultural Brain Hypotheses (CBH), because of how evolutionarily alien these species are, and how strange their underwater world is compared to the world we inhabit. We have previously tested the CBH predictions with primates, but their evolutionary closeness to humans means that the relationships we find may be due to our evolutionary logic or due to these features (such as large brains and high sociality) being present in a common ancestor. Thus finding these relationships in cetaceans is strong evidence for the evolutionary logic. It also sets up cetaceans as an interesting control group for understanding human evolution.
The ongoing massive media response and public interest in marine mammals and the evolutionary sciences was heartwarming. Altmetrics suggested a score of 1026, in the top 5 of articles in Nature Ecology and Evolution, receiving the most attention of recent articles and top 50 of all articles of a similar age. Highlights included several video and audio interviews, including with BBC World News, BBC World Service Radio “Science in Action”, CBC “The Broadcast” (below), and the front page of the print edition of the The Times and front page of the website of The Guardian.
Selected Media Coverage
Scientific American (republished in January print edition of magazine)
Some unexpected places, including Cosmo 🙂
On Thursday, I was at the Council of Graduate Schools (CGS) Annual Meeting in Washington, DC to receive this year’s CGS/ProQuest Distinguished Dissertation Award in the Social Sciences. The award ceremony was held in the Regency Ballroom of the beautiful Omni Shoreham. The press release with more details can be found here: http://www.proquest.com/about/news/2016/Winners-of-2016-CGS-ProQuest-Distinguished-Dissertation-Awards.html.
It was an unexpected honor, but also validation of my research agenda and approach to science. My acceptance speech was a brief summary of my dissertation and Dual Inheritance Theory and Cultural Evolution more generally.
I was invited to present my work on human evolution and the evolution of brains at the “Evolution of cognition and longevity: Adaptation to a new technological environment” meeting at the Grande Galerie de l’Evolution, National Museum of Natural History in Paris, France. I presented “The Cultural Brain Hypothesis & Information Grandmother Hypothesis: How culture drives brain expansion and alters life history”, where I discussed the Cultural Brain Hypothesis (my dissertation; paper currently under review). I also presented some work in progress on the Information Grandmother Hypothesis.
The Cultural Brain Hypothesis is a more parsimonious explanation for the relationships that have been shown between brain size, group size, adaptive knowledge, social learning, and aspects of life history. The Cumulative Cultural Brain Hypothesis is a set of predictions derived from the evolutionary processes that lead to these relationships for the conditions that lead to an autocatalytic take-off between brain size and adaptive knowledge – the uniquely human pathway. The Information Grandmother Hypothesis extends this theory to explain the evolution of menopause and lifespan.
Speakers were biologists of all kinds. Speakers included:
Herve Chneiweiss (UPMC)
Barbara Demeneix (MNHN)
Donata Luiselli (University of Bologna)
Jean-Marie Robine (GDR INSERM/EPHE)
Kaare Christensen (Danish Aging Research Center)
Eline Slagboom (Leiden University Medical Center)
Claudio Franceschi (University of Bologna)
David Hill (University of Edinburgh)
Paolo Garagnani (University of Bologna)
Eileen Crimmins (USC Davis School of Gerontology)
Dorly Deeg (VU University, Amsterdam)
Carol Brayne (CFAS)
Carole Dufouil (INSERM)
Dominique Grimaud-Herve (MNHN)
David Raichlen (University of Arizona)
Viviane Slon (Max Planck Institute for Evolutionary Anthropology)
James R Carey (UC Davis)
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):
- Who we learn from (e.g. skilled, successful, and prestigious models; conformist transmission)
- What moderates these choices (e.g. self-similarity, age, sex, ethnicity; Credibility Enhancing Displays, CREDs).
- 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.
- 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.
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 Boyd, Joan Silk, Kim Hill, Sarah Mathew, Charles Perreault, Michelle Kline, and Matt Gervais.
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.
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.
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 Navarrete, Daniel 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.