Tag Archives: cultural evolution

Podcast: Brighter than Bagpuss – BBC’s Radio 4 Sideways

I appeared on the latest episode of BBC Radio 4’s Sideways.

My snippets:

Listening options for the full episode:

https://www.bbc.co.uk/sounds/play/m000xr8p

Description

Matthew Syed looks at how kids’ TV got smart, and what we can learn about the developing mind from the program makers who led the way. I discuss the role of cultural evolution in this phenomenon.

Boston, Massachusetts. 1970. A group of mothers and young children assembles outside the offices of the local TV station. It’s the first phase of a fight to improve kids’ TV that would go all the way to the United States Senate. In the late 1960s, children’s television in the US was dominated by cheap cartoons and adverts for sugary snacks. Peggy Charren had something to say about it. She formed a grassroots activism group in her living room with other concerned mothers – Action for Children’s Television. It would become one of the most influential broadcast lobbying groups in history. Peggy was part of a wave of people who were starting to take kids’ TV seriously. From the creators of Sesame Street to psychological researchers like Professor Daniel Anderson who brought science into children’s program-making, Matthew draws out what we can learn from these innovators who know how to create a hit show.

So many great points included from the other guests:

  • Debbie Charren, Peggy’s daughter, and former schoolteacher and reading specialist;
  • Robert Krock, Action for Children’s Television’s former development director;
  • Daniel Anderson, Professor Emeritus at the Department of Psychological and Brain Sciences, University of Massachusetts Amherst;
  • and Andrew Davenport, creator, writer and composer of In the Night Garden, Moon and Me, and Teletubbies.

My thanks to presenter Matthew Syed, producer Caroline Thornham and editor Katherine Godfrey.

Cultural Evolution of Genetic Heritability

Summary from Twitter thread:

New target article on “Cultural Evolution of Genetic Heritability” with Ryutaro Uchiyama & Rachel Spicer in Behavioral and Brain Science (BBS). Preprint available at muth.io/cegh.

Long post, but an important topic that helps to resolve controversies such as IQ differences.

Quick summary: We reconcile behavioral genetics and cultural evolution under a dual inheritance framework. A cultural evolutionary behavioral genetic approach cuts through the nature–nurture debate and helps resolve controversies such as IQ.

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Business is booming in behavioral genetics. We’re in the midst of a GWAS gold rush. Powerful computers and sequenced DNA of millions has led to an industrious search for SNPs that correlate with a variety of traits. Some even claim the curse of reverse causality has been lifted.

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There’s also been a parallel revolution in cultural psychology and cultural evolution. Genes, culture, and the environment have often co-evolved, shaping our species. But the revolutions in behavioral genetics and cultural evolution have largely been independent. But, given the extensiveness of the cultural and culturally-shaped environment, cultural evolution offers an important but typically missing complement to otherwise insightful methodological and empirical analyses within behavioral genetics. Genes and culture are intertwined. For example, our jaws too weak and guts too short for a world w/o controlled fire & cooked food. It’s obvious that lower environmental variation will lead to higher heritability scores. Less obvious is how culture can mask or unmask genetic variation. Or how diffusion and innovation can increase or decrease heritability. Or how to define a single society for the purposes of measuring heritability, without being able to identify cultural cleavages that can lead to Scarr-Rowe type effects: en.wikipedia.org/wiki/Scarr-Row…

Reconciling behavioral genetics & cultural evolution offers insights for differences in heritability between and within populations, differences in heritability across development, and the rise in IQ (Flynn Effect). We’d like a discussion that nuances common interpretations of the nature and nurture of behavior.

First, let’s quickly get a common misinterpretation of heritability out of the way: Heritability is not an index of the genetic basis of a trait nor a measure of the relative contribution of nature compared to nurture. It’s the proportion of phenotypic variance for some trait that is explained by genetic variance. So obviously variability in genes, in environment, and in traits will all matter. A quick illustration: skin pigmentation and UV levels. Genes affect level of skin pigmentation and propensity for tanning instead of burning; ancestral adaptations to UV radiation at different latitudes.

Migration means melanin is mismatched to latitude: Aussies with European ancestry are more susceptible to skin cancer; Europeans with African and South Asian ancestry have higher rates of vitamin D deficiency.

A Gene×Environment approach won’t predict how heritability estimates change over time as non-genetic adaptations compensate for genetic mismatches: fairer Australians wear sunscreen, a hat, & covered clothing; darker Europeans consume vitamin D supplements & vitamind D-rich or fortified foods. Here it’s easier to see that heritability is a function not only of genes, traits, and ecology, but also of an evolving cultural environment. The environment is not an inert backdrop against which genes should be evaluated. It evolves in relation to both genes and ecology.

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Four lessons before we continue. The first is obvious to behavioral geneticists, the second sometimes noted, the third and fourth are typically missing.

Lesson 1

There is no overarching, one-quantity heritability of a trait to be discovered. There is no fixed answer to the question, “What is the heritability of skin cancer?”

Lesson 2

Heritability will depend not only on ecology, but also on culture & specifically on diffusion and innovation—both of which can rapidly change and therefore rapidly change heritability estimates.

Lesson 3

Diffusion and innovation are broadly directional. Cultural diffusion of sunscreen, clothing, shade & sunglasses, and cultural innovation toward more effective screening and treatment of melanomas all work to reduce heritability estimates due to a masking effect.

Were any of these an example of culture unmasking genetic effects, such as tanning salons that induce differential risk according to skin pigmentation level, we would have predicted an increase in heritability.

Lesson 4

We might expect a stronger cultural response where ecological and cultural selection pressures are stronger—skin cancer mitigation in Australia but Vitamin D supplementation in northern Europe. Not been tested to our knowledge, but the predictions are clear.

“Which SNPs are associated with skin cancer?” is similarly culturally dependent. Societies where sunscreen use is common, we expect SNPs associated with skin pigmentation to be less predictive of skin cancer compared to societies where this is not the case.

Similarly, we would expect SNPs associated with antioxidant metabolism to be less predictive of skin cancer in societies whose foods are rich in antioxidants—such as in traditional Mediterranean cuisine.

Section 2.2 is on how cultural evolution shapes heritability through diffusion and innovation. We live on the peaks climbed by cultural evolution – human environments have already been shaped by cumulative cultural evolution—functionally overlapping with genetic evolution.

Diffusion and invention can mask or unmask genes. Examples using language, fertility, and schooling.

Language example

If Cantonese or Yoruba (both tonal) spread, heritability of language ability would increase proportional to variation in “tone” genes.

If Norwegian or Russian (both non-tonal) spread in the same population, heritability of language ability would decrease.

Fertility example

Contraception and social values in 20th century unmasked the effect of genes associated with reproductive behaviors and preferences (heritability rose in US).
But a one-child policy or rigid childbearing norms masks the genetic effect.

School example

School is a powerful mechanism for cultural diffusion. Heritability of literacy in:

Australia:
Kindergarten: 0.84
Grade 1: 0.80

Scandinavia:
Kindergarten: 0.33
Grade: 0.79

Why?

Cultural diffusion of literacy.

Australian children begin receiving compulsory literacy instruction in kindergarten, while in Scandinavia the kindergarten curriculum emphasizes social, emotional, and aesthetic development—literacy instruction only begins in Grade 1.

Assessing the genetic basis of literacy without accounting for particulars of curricula on cultural diffusion is a selection bias of unknown magnitude. Note that literacy in the home environment is already shaped by cultural evolution; there is no ‘baseline’ heritability. Heritability is a composite measure that captures both genes and culture. Saying literacy heritability in Scandinavia jumps up to 0.79 in Grade 1 reveals as much if not more about the disseminative power of modern schooling than it does about the genetic basis of literacy. Similar dynamics with innovation. Read about it in the paper.

However, one neglected factor is “cultural clustering”, where even highly useful forms of cultural knowledge may not easily permeate social barriers. Not necessarily ethnic boundaries, also class, wealth, occupation, political alignment, religion, or incidental geographic layout. Greater differential clustering can lead to a cultural Simpson’s paradox (we’ll get to that shortly, but see Section 3.4).

Cultural FST (CFST) is useful for identifying these clusters. You can read more about that paper here: https://michael.muthukrishna.com/beyond-weird-psychology-measuring-and-mapping-scales-of-cultural-and-psychological-distance/

Hopefully, you can see the importance of a cultural evolutionary behavioral genetics. We hope this target article will spark a vibrant discussion. But let’s move onto the problems that obscure the effect of culture:

(1) the WEIRD Sampling Problem

(2) the Hidden Cluster Problem

(3) the Causal Locus Problem

And then describe the:

(4) Cultural Simpson’s Paradox that emerges at their junction.

The WEIRD Sampling Problem

The WEIRD people problem? Pretty bad in genetics too.
Twin studies:
94% Western: 60% US, UK, Aus; 25% Nordic
6% Non-Western: 4% China, Japan, South Korea, Taiwan

Remainder of the world, i.e. vast majority of humans are the remaining 2%

Same story in GWAS:
88% European ancestry.
72% from just 3 countries: US, UK, & Iceland
20% from Japan, China, and South Korea

From a cultural evolutionary perspective, given (a) cultural environment, (b) coevolution b/w culture & genes, & (c) cultural differences between populations, not surprising that: 1.Polygenic scores don’t translate well across ancestry groups (European scores, 42% in Africa)
2. Polygenic scores are highly sensitive to inadequately controlled population stratification. And so cultural variation and the hidden cluster problem is pernicious.

Hidden Cluster Problem

Cultural clusters (or segregated diversity) typically created by barriers impeding cultural transmission, such as topography, cultural conflict, language, social stratification by class, wealth, etc. Immigrant countries more clustered (Canada > Japan).

Countries whose borders are drawn arbitrarily with respect to the geographic arrangement of cultural groups, for example by colonial administration (many countries in Africa), are also likely to have high clustering. You can use CFST to find them: https://journals.sagepub.com/doi/abs/10.1177/0956797620916782

Note that cultural clustering is not the same as genetic clustering as we explain at length in Section 3.2.2. Indeed, reconciliation between cultural evolution and behavioral genetics requires an update in the way we think about culture.

Causal Locus Problem

Hidden cluster problem describes complexity that exists w/in social groupings. Culture is not an unstructured exogenous variable. Culture is constructive system that accumulates functional adaptations in a directed manner over time. Two key lessons here.

Lesson 1: Genes that make vs genes that break. The more complex a system, the more ways it can fail. Take the history of lighting.

Wood fire can be extinguished in 2 ways
Flourescent bulbs have 7 ways to fail
LEDs have 30

Faulty O-ring can explode a space shuttle and so on.

There is a fundamental asymmetry: easier to find ways to break the system than ways to explain or improve it. So too for gene function. All your cells have the same bootstrapped code, but they interact with each other, what they create, and their surroundings to create you.

There are many ways these interactions can go wrong. It is easier to identify deleterious genetic mutations than beneficial mutations. The space of failure is larger than the space of success, making genes that break more detectable than genes that make. For example, a single mutation can cause Mendelian disorders such as cystic fibrosis and Huntington’s disease, but no single mutation creates genius. Over 1000 genes have been linked to intelligence.

Each gene only explains a miniscule fraction of variation in intelligence, and the causal mechanisms are unlikely to be straightforward. In contrast to these genes that make, the causal mechanisms behind single gene mutations that cause intellectual disability—e.g. BCL11A, PHF8, ZDHHC9—are relatively well understood.

Increasing nutrition, improving schooling, and removing parasites have positive effects on IQ, but in a society where parasite infection is kept under control, we would not notice that parasite status correlates with intelligence. And by corollary, genes that provide protection against malnutrition, parasites, or pollution would only be positively associated with intelligence in environments where these insults occur. In environments where these insults have been removed, the same genes would not be associated with intelligence, and can even be deleterious, as with sickle cell trait. Not helpful if there’s no malaria.

Genes are functionally masked by cumulative cultural evolution, and we expect that this masking is extensive and systematic. A quick evolutionary and historical example: Vitamin C, the GLO gene, and dead sailors.

Vitamin C is an essential nutrient and its acquisition is thereby an essential biological function. Endogenous synthesis of vitamin C requires a gene called GLO, and GLO is present across most of the animal kingdom. But because vitamin C synthesis is metabolically costly, the gene is inactive in some species that have access to sufficient quantities of the nutrient in their diets. e.g. taxa such as teleost fishes, guinea pigs, many bats, some passerine birds, monkeys and apes.

Anthropoid primates occupy a frugivorous niche, and fruits often contain sufficient vitamin C. Here gene function is offloaded onto environmental resources. In turn, this offloading has behavioral implications. If a species becomes dependent on its environment for vitamin C, both its behavioral range and evolutionary trajectory become constrained by the availability of the nutrient. Humans are a nice example of this.

As our species migrated across the planet, we found ourselves in environments where vitamin C was in short supply. A deficiency of vitamin C causes scurvy—the bane of seafarers until the trial-and-error discovery that certain food items like sauerkraut and citrus could prevent ships from being packed with tired, bleeding, toothless, and eventually dead sailors.

Masking does not necessarily need to be in the direction from culture to genes: genetic assimilation is same process working in the opposite direction, where a trait that is regularly acquired through learning gradually transfers its locus to the genome (i.e. Baldwin effect).

Cultural Simpson’s Paradox

Which leads us to the Cultural Simpson’s Paradox. Causal Locus Problem can confound the measurement of genetic effects due to Hidden Cluster Problem obscured by WEIRD Sampling problem creating a Simpson’s paradox.

Let’s return to the UV example. The melanin-UV mismatch can be masked by the cultural diffusion of sunscreen, especially in regions with more exposure to sunlight. In other parts of the world, the issue is under-exposure to the sun causing vitamin D deficiency. Low vitamin D leads to lack of bone integrity, muscle strength, autoimmune disease, cardiovascular disease, cancer etc.

In US and France, more north you go, the the lower vitamin D levels. Makes sense, right?

But when we compare across Europe, we see the opposite pattern where people in northern countries have higher vitamin D than people in southern countries. What’s going on?

High consumption of fatty fish and cod liver oil in Northern Europe, as well as greater sun-seeking behavior in these countries compared to Mediterranean Europe. These are potent cultural adaptations.

Participants fed the traditional Norwegian fish dish mølje three times over a span of two days had 54 times the recommended daily dosage of vitamin D. The relationship between latitude and Vitamin D goes one way within a country, and the other way between the countries.

If we had been Martian anthropologists who did not know that the populated landmass known as “Europe” can in fact be broken down into sub-units called “countries”, these examples would be standard examples of a Simpson’s paradox.

In these cases, the paradox occurs when we do not know how to partition the higher-order population (Europe) into lower-order units. Fortunately, we can partition continents into countries, but in other cases, the relevant units is not as easily identifiable. Let’s move on.

We now have enough to make sense of puzzles in behavioral genetics such as (1) differences in heritability across socioeconomic levels, (2) differences in heritability across development, and (3) the Flynn effect. 

SES: Heritability of IQ is higher among affluent, high socioeconomic status (SES) households than among poorer, low-SES households in some societies, but mixed in others. Why?

One explanation is ‘reciprocal causation’: genes well suited to a task can better nurture their skills in a wealthier environment than in a poorer environment and this is amplified over time. Maybe, but then why don’t we see the effect in Europe and Australia?

Here’s what we think is going on: in the US, the differences between school and home environments among high-SES households is smaller than among low-SES households. US is a land of variance. Factors such as school lotteries can dramatically affect the cultural input.

In contrast, the cultural environment is less unequal in western Europe and Australia, where, for example, high quality schools are available across SES. Where these two explanations make different predictions is for poorer countries.

Reciprocal causation would predict low heritability in poorer countries. We would predict high heritability where there is equal access to similarly poor schools and household conditions, but low heritability if inequality is high.

Incidentally we predict the opposite between human and animal environmental effects due to social transmission. It’s interesting, but not central. Check out Section 4.1.2. Let’s move onto heritability across development.

Heritability changes over the lifespan. Heritability of political orientation is similar for American identical and fraternal twins from middle childhood up to early adulthood. Right around the age at which American children leave home, this pattern is broken.

Drops for fraternal but not identical. We argue this is due to vertical vs oblique transmission and would predict a different drop off for say Italian or Croatian who leave home past 30.

Flynn effect describes the rise in IQ test scores over time. Largest in countries that have recently started modernizing, and smallest in countries that had attained modernization. No consensus to explain it, but given speed genes obviously unlikely.

We argue its caused by a rapid worldwide increase of cultural practices, technologies. Intelligence is about hardware—genes, parasites, pathogens, pollution, and nutrition affecting health and brain development, but also software—our increasingly complex cultural package.

By this account, not only is the idea of a culture-free IQ test implausible, but so too is the idea of culture-free IQ. Lots to say here. Go read Section 4.3.

Home stretch: Cultural Evolutionary Behavioral Genetics. The thrust of our theoretical case is that human psychology and behavior have a large cultural component that has been changing over history.

Most recently our psychology has been shaped by the advent of writing, numeracy, different types of agriculture, the Industrial Revolution, the Internet, and smart phones.

As new adaptive traits emerge, initially those who possess these traits will have an advantage, as in the case of access to new food sources, better healthcare, more efficient technologies, or easier methods of learning.

But eventually the traits will reach fixation in the population through the processes of cultural diffusion, at least until they are unseated by subsequent innovations. We predict that these cultural dynamics are reflected in heritability estimates.

As any geneticist knows, genetic heritability is a function of the variability in the environment, variability in genes, and variability in the phenotype. There is little to predict if the phenotype is homogenous, as in the number of fingers or kidneys.

There is little to predict with if the environment or genes are homogenous. But what is factored into the environment includes not only the physical ecology, but also the cultural environment.

While variance in genes and ecology may be relatively stable, the variance in the cultural environment is continually changing through the processes of cultural evolution. A genetic account of human psychology and behavior must also account for culture and cultural evolution.

Section 5 and the conclusion tie everything together, but I’ll leave you to read it (muth.io/cegh). There’s a formal model with some pretty graphs in the Appendix:

Grand Challenges for Human Flourishing Award

I was selected as one of 11 teams of researchers to receive inaugural awards of the Grand Challenges for Human Flourishing with a project titled ‘What does cultural evolution look like in the 21st century, and how can we use the answer to ensure continued human flourishing?’.

Templeton World Charity Foundation (TWCF) announced the initial investment in a $60 million commitment for bold research that pushes the boundaries of scientific knowledge to help people flourish.

More than 500 teams of scientists from over 350 academic institutions across the world answered the request for ideas, which push beyond traditional measures of physical and mental health to include happiness, meaning and purpose, spiritual well-being and striving in adversity. The 11 awards represent the work of more than 40 researchers at over two dozen institutions and amount to more than $1 million to encourage further exploration of these ideas and the advancement of science in human flourishing.

Some of the questions I hope to tackle include:

  • What does cultural evolution look like when people are united by a global Internet, but separated by filtered social network feeds?
  • How does our social learning psychology interpret this information to decide what is true, what others think, and whom we can trust?
  • What does cultural evolution look like when people separated by geographic and cultural distance regularly interact and even live together in the same country?
  • How do societies with very different cultural evolutionary histories find common ground to cooperate on global challenges?

Cultural evolution and dual inheritance theory are the closest we have come to a “theory of human behaviour” and “theory of social change”. But so far, we’ve focused our efforts on understanding the past – human origins and human history – rather than understanding the present or preparing for the future. The framework offers answers for what has led to human flourishing thus far, how we’ve overcome challenges on the path toward greater cooperation, and why some societies have diverged from others. I will be helping the Templeton World Charity Foundation (TWCF) strategise about how cultural evolution works in the 21st century. How this framework that helps explain human flourishing can also help ensure continued flourishing—support economic development, strengthen democratic institutions, and catalyse collective action to tackle the challenges of a post-climate changed world.

More about the Grand Challenges for Human Flourishing can be found on the TWCF website: https://www.templetonworldcharity.org/rfi/ideas

Cultural Brain Hypothesis, Collective Brains, and the Evolution of Intelligence at Dysoc Webinar Series on Human Origins and Cultural Evolution: Celebrating the 150th anniversary of the Descent of Man [online]

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:

The ties that bind us at Beveridge 2.0. Symposium: Reciprocity across the life-cycle [online]

I gave a talk on “The ties that bind us” at the Beveridge 2.0. Symposium: Reciprocity across the life-cycle hosted by STICERD and the LSE School of Public Policy The talk applied the science of cooperation to the problem of the future welfare state, particularly around pensions and retirement. A corresponding paper is under review at LSE Public Policy Review.

Cooperation and the moral circle: When cooperation harms the collective good at SPSP 2021 Justice and Morality Pre-Conference [online]

I gave a talk on “Cooperation and the moral circle: When cooperation harms the collective good” as part of the SPSP 2021 Justice and Morality Pre-Conference. It’s part of some new work on the problem of the expanding moral circle as it links to cooperation, corruption, prosocial, and antisocial behavior. A related working paper is available here: https://www.biorxiv.org/content/10.1101/2021.02.19.432029v2

Interview with Kensy Cooperrider on Many Minds

I had a fun, far-reaching, free-ranging conversation about my research and research motivations with Kensy Cooperrider on Many Minds.

Listening options:

Description

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.”

40:27 – The so-called Flynn Effect refers to the puzzling rise of IQ scores over time. It is named after James Flynn, who died only weeks ago.

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:

Joseph Henrich, The Secret of Our Success & The WEIRDest People in the World

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/).

You can subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you like to listen to podcasts.

We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com.

For updates about the show, follow us on Twitter: @ManyMindsPod.

Psychology as a Historical Science

Summary from Twitter thread:

New paper on “Psychology as a historical science” in Annual Review of Psychology. Catalyzing the field of “historical psychology” by reviewing work on: origins of psychology and institutions today, psychology of the past (data from dead minds).

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Our psychology is shaped by our societies, and our societies are shaped by their histories. We can do better than butterfly collecting–just measuring cross-cultural diffs. For psychology to develop a full theory of human behavior, we need historical psychology.

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Psychology is shaped by millions of years of genetic evolution, thousands of years of cultural evolution, & a short lifetime of experience; yet, much of the field has focused on that short lifetime of experience. The WEIRD People Problem is not only about geography but history.

Past societies can be as culturally distant as distant societies. Cohort effects are a sliver of the cross-temporal variation we would expect in a culturally evolving species. History serves as a kind of psychological fossil record, a source of “data from dead minds”.

We (1) review work in historical psychology; (2) introduce methods including causal inference & how to extract data from dead minds; (3) explore the role of theory in mapping history to psychology; and (4) provide some conclusions concerning the future of this field.

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E.g.s: Religious evolution & social psych. Some gods gained the ability to see into hearts & control an afterlife contingent on compliance. In many large-scale societies, these gods became omniscient, omnipotent, & omnibenevolent, coevolving with the scale of their societies.

This historical theory makes predictions not only about expected relationships in the historical record but also about expected contemporary cross-cultural diversity in religious beliefs and cognition. In doing so, the theory links historical psychology to cultural psychology.

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WEIRD Psychology may have its origins in suppressing kin networks, changing family structures, & related via one particular religion: The Catholic Church

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Institutions rest on invisible cultural and psychological pillars. E.g. a constitution’s proclamations are irrelevant without a belief in the rule of law, or norms of punishment for violations of this rule.

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We discuss the importance of causal inference techniques in historical psychology: instrumental variables, difference-in-differences, regression discontinuity. Some e.g. use for slavery & trust in strangers; agriculture & sex diff, gender inequality, collectivism; personality.

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Historical psychology includes the psychology of the past – data from dead minds, cognitive archeology. Historical databases are emerging. But sometimes the data is qualitative requiring tools like text analysis.

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We discuss some examples of the importance of theory. A society has codependent norms, values, beliefs, behaviors, and institutions. If one takes an exploratory approach and looks for correlations in history, there are many to be found. Theory helps clarify causality.

Collaboration between psychologists, historians, and other humanities scholars is important (see religiondatabase.org for an e.g.). We discuss challenges & strategies.

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Taking history seriously is a critical part of moving beyond the WEIRD people problem and making psychology a genuinely universal science of human cognition and behavior.

National Academy of Engineering

Cultural Evolution and the Paradox of Diversity

Summary from Twitter thread:

As an engineering grad, I’m delighted to contribute to the latest National Academy of Engineering Bridge issue on “The Paradox of Diversity” https://nae.edu/244742/Cultural-Evolution-and-the-Paradox-of-Diversity

It’s short, but here’s a quick trailer.

Cultural evolution and the paradox of diversity

Diversity is a double edged sword. Governments and organizations often push for greater diversity and tolerance for diversity, because the human tendency is toward squashing difference and selecting others like ourselves. But diversity can both help and harm innovation.

On the one hand, there’s intellectual arbitrage: discoveries and technologies situated in one discipline that draw on a key insight from another. Here diversity is a fuel for the engine of innovation.

On the other hand, diversity is, by definition, divisive. Without a common understanding, common goals, and common language, the flow of ideas in social networks is stymied, preventing recombination and reducing innovation. How do we reap the benefits without paying the costs?

Consider the challenge of collaborations between scientists and humanities scholars (or even between scientists in different disciplines). The key is to find common ground through strategies such as optimal assimilation, translators and bridges, or division into subgroups.

Resolving the tension between diversity and selection is at the core of a successful innovation strategy. And there are many possible solutions.

Some dimensions of diversity matter more than others—without a common language, communication is difficult. On the other hand, food preferences create little more than an easily solved coordination challenge for lunch.

But between these are many dimensions where optimal assimilation may be desirable and traits can be optimized, such as psychological safety so people feel free to share unorthodox ideas.

Other strategies include interdisciplinary translators. In my role at the Database of Religious History (DRH)—a large science and humanities collaboration—we have benefited from a few scholars trained in both to bridge the gap.

Innovation can also be divided into independent groups, coordinating within the group but competing against others trying different strategies (e.g. competition between firms).

Check out the full issue here: https://www.nae.edu/244665/Winter-Issue-of-The-Bridge-on-Complex-Unifiable-Systems

Behavioral Science for Global Good at Behavioral Insights Group (BIG) conference hosted by Harvard Business School / Harvard Kennedy School, Harvard University, Cambridge, MA

I was a panelist at the  Behavioral Science for Global Good at Behavioral Insights Group  (BIG) conference hosted by Harvard Business School (add link) / Harvard Kennedy School (add link). The goal of the panel was to offer insight into the ways in which behavioral science may need to change in the future in order to fulfill its stated mission to make a positive difference in the world—particularly on how to expand our focus beyond predominantly WEIRD researchers, WEIRD research topics, and WEIRD populations.

My fellow panelists included:

  • Dolly Chugh, Associate Professor of Management and Organizations at NYU
  • Chaning Jang, CSO / VP of Research at the Busara Center for Behavioral Economics
  • Shinobu Kitayama, Robert B. Zajonc Collegiate Professor of Psychology at University of Michigan
  • Steven Roberts, Assistant Professor of Psychology at Stanford University
  • Neela Saldanha, Senior Advisor at the Busara Center for Behavioral Economics – who did a wonderful job chairing the discussion.

“What affects our level of intelligence?” at the Diverse Intelligences Summer Institute hosted by the Templeton World Charity Foundation at the University of St Andrews, Scotland, UK.

This year’s Diverse Intelligences Summer Institute was held online due to the pandemic. I delivered a lecture over Zoom on “What affects our level of intelligence?” followed by a lively discussion with the students. The lecture discussed brain evolution, the Cultural Brain Hypothesis, collective brain, and a cultural evolutionary account of intelligence. You can watch it below:

Communication and Competition at the Learning Innovations LaBarge tree “LILA” at the Harvard Graduate School of Education, Cambridge, MA

 I ran a workshop on communication competition at the Learning Innovations Laboratory (LILA), part of Project Zero at the Harvard Graduate School of Education. The LILA group include people from industry and the military. We discussed various aspects of the science of cooperation, including how and when it fails.I also introduced some new work on the paradox of diversity and on measuring cultural distance.

One of the participants, Sue Borchardt is now making an animated series based on the talk.

Beyond WEIRD Psychology: Measuring and Mapping Scales of Cultural and Psychological Distance

Summary from Twitter thread:

🚨Now out in Psychological Science! Beyond WEIRD Psychology: Measuring and Mapping Scales of Cultural and Psychological Distance

https://journals.sagepub.com/doi/10.1177/0956797620916782

1/ The world is not WEIRD vs non-WEIRD.

How psychologically and culturally distant is the US from Canada? China from Japan?

2/ CFst is a lens for looking at differences between and within populations. It’s flexible, robust, and theoretically-meaningful.

Issue with existing approaches:
1. Societies are distributions of traits. Mean estimates are misleading. Brazil looks like Turkey on Hofstede:

2. Variance captures some of this (Turkey is culturally tighter than Brazil), but how do you capture nominal traits like political priorities: “give people more to say”, “maintain order in the nation”, “fight rising prices”, or “protect freedom of speech”?3. Genetic distance is a proxy, but can be misleading: Hong Kong is more than an order of magnitude more genetically similar to China than to Britain, but is culturally similar to both due to Britain’s century-long history in Hong Kong.4. Linguistic distance is better, but the resolution is low. Difficult to distinguish the cultures of Australia, Canada, the UK and the US, all of whom speak English.3/ Fst is theoretically meaningful within evolution: measures how genotype frequencies forsubpop differ from expectations if there were random mating over the entire population. i.e. it measures the degree to which the populations can be considered structured and separate.4/ For cultural inheritance, this is directly analogous to between-group differentiation caused by selection, migration, and social learning mechanisms.5/ Cultural FST (CFst) is calculated in the same manner as Genetic FST, but instead of a genome, we use World Values Survey as a “culturome”.
Questions as loci.
Answers as alleles.

CFst can handle continuous, binary, or nominal traits.6/ Because traits tend to cluster within a society, it’s also robust to missing questions or data. You can drop even 50% of data or questions and get very little deviation.

Even if we don’t ask every conceivable question, if you ask a broad range, you’ll get a similar answer.

Note: Traits cluster within, but not necessarily between societies. 7/ We create an American scale (useful as a proxy WEIRD scale) and a Chinese scale as an example.

8/ American scale correlates with cultural dimensions, tightness, values, extraversion and personality variance, and many behavioral measures: blood donations, diplomat parking tickets, corruption perceptions, honesty in the wallet drop study:

Civic honesty around the globeRationalist approaches to economics assume that people value their own interests over the interests of strangers. Cohn et al. wanted to examine the trade-off between material self-interest and more a…https://science.sciencemag.org/content/365/6448/70

Distance…

9/ The Chinese scale is less predictive – why? Two possibilities:

1. WEIRD nations are truly psychological outliers in some objective sense. Plug for @JoHenrich ‘s brilliant new book: amazon.com/WEIRDest-Peopl…

2. Psychological measures have been studied because they are remarkable to WEIRD researchers.

If psychology was dominated by Chinese psychologists, we would see a different set of psychological outcomes covered in textbooks. 10/ Resolving which of these explanations is correct will require greater diversity in both researchers and samples.11/ Final caveats:
1. Similar distance from US / China does not mean cultural similarity. Japan & Norway are similarly distant from US, but are not necessarily similar to each other.

Like Colombia and the UK are similarly geo distant from US but nowhere near each other.

Culture is a large n-dimensional space. 2. The US is relatively homogeneous (note, it’s a loose country, but similarly loose in all regions relative to other large populations). Societies are not homogeneous. They have multivariate distributions of many traits along many dimensions with structure within structure.

There are likely to be cultural differences between not only regions within a country but also ethnicities, religions, socioeconomic class, and other groupings. These are all avenues for future research. 3. We need more data from the Middle East and Africa! We have every reason to suspect the American scale will continue to stretch as we map out these psychological terrae incognitae.These regions (and others like South Pacific) are a treasure trove for the next generation of cultural psychologists. Not just about psychological outcomes, but also questions we ask, and way we organize psychology. What we know is the tip of the iceberg of the human psyche. END I lied. There’s also a website: culturaldistance.com

Selected Media Coverage

Nautilus

Marginal Revolution

Beyond WEIRD Psychology: Measuring and Mapping Scales of Cultural and Psychological Distance at Brunel University, London

I was delighted to discuss my recent paper on measuring cultural distance “Beyond WEIRD Psychology: Measuring and Mapping Scales of Cultural and Psychological Distance” at the Center for Culture and Evolution (add link to center) of Brunel University (add link to university). The center is emerging as an exciting and quickly growing hub for cultural evolutionary research.