The Evolution of Culture with Joseph Henrich [S2 Ep.20]

Summary

Podcast Summary: Conversations With Coleman

Episode: The Evolution of Culture with Joseph Henrich [S2 Ep.20]

Original Release Date: June 26, 2021
Host: Coleman Hughes
Guest: Joseph Henrich, Professor of Human Evolutionary Biology at Harvard University

---

Overview

This episode explores the profundity and pervasiveness of culture in shaping human evolution, psychology, and society. Coleman Hughes engages with Joseph Henrich to discuss his groundbreaking work on cultural evolution, gene-culture coevolution, the WEIRD (Western, Educated, Industrialized, Rich, Democratic) phenomenon, and how cultural practices can shape human biology and institutions. They delve into practical and sometimes surprising examples—from the necessity of faith in cultural traditions to the neural impact of literacy and dairy consumption—offering a compelling case for why humans owe much of their success and uniqueness to the cumulative legacy of culture.

---

Key Discussion Points & Insights

1. Henrich's Intellectual Journey & the Limits of Traditional Anthropology

• Background: Henrich describes his disillusionment with anthropology’s explanatory power, leading him toward evolutionary approaches integrating psychology and economics.
  • “Humans are a cultural species heavily reliant on learning from other people, and how that can be integrated into an evolutionary approach.” (03:51)
• Problem in the Field: Traditional models (especially in economics and anthropology) have failed to account for how culture actively shapes preferences and beliefs.

---

2. Nature of Cultural Evolution & Its Biological Effects

a. Culture Goes Beyond Platitude

• Conservative Assumptions: Many fields ignore or minimize the impact of culture, treating it as separate from or secondary to biological evolution.
• Henrich’s View: Culture is a driving force in shaping not just human behavior but the very structure of our brains and physiology.
  • “Many of our human unique adaptations are actually responses to features constructed through cultural evolution.” (06:08)
  • Example: Literacy physically alters the brain, changing regions related to facial recognition. (09:21–10:10)

b. Non-Trivial Brain Changes

• Acquiring Cultural Practices Physically Changes the Brain:
  • Learning to read thickens the corpus callosum and creates specialized neural circuitry; it also shifts facial recognition processes (10:10).
  • Literacy can actually make individuals slightly worse at facial recognition due to repurposing of neural real estate (10:16).

---

3. Humans: Cultural Addicts More Than Intellectual Giants

• Comparative Studies: Human children and apes have similar individual cognitive capacities; distinguishing factor is humans’ extraordinary social learning and imitation abilities.
  • “We seem to be cultural learning machines... as adults, we outperform apes in cognitive tasks because we are downloading large amounts of inherited cultural knowledge.” (12:01)
• Vulnerability Without Culture:
  • Stranded explorers often die in environments where hunter-gatherers thrive, lacking knowledge (14:18).
  • “We’re a species that's addicted to culture in ways that other species who have some culture really aren’t.” (13:28)

---

4. Implicit Wisdom in Cultural Traditions

• Empirical Examples:

  • Manioc (Cassava) Preparation:
    • South American tribes have intricate, time-consuming preparation routines that detoxify cyanide, though practitioners rarely know the reason.
    • Transplanted to Africa, new populations suffered disease due to lack of these traditions (15:33–17:34).
  • Corn and Pellagra:
    • Pre-Columbian Americans used ash in cornmeal to free niacin, preventing pellagra. Europeans missed this, resulting in outbreaks (18:30).

• Cultural Faith:

  • “Humans evolved to put faith in these traditional practices that get passed down... compared to other species, we're much more willing to pay costs, do it the way we've been taught.” (18:30)

---

5. How Humans Acquire Culture: The 'Who,' 'When,' and 'What'

• Selective Cultural Imitation:
  • Children don’t learn indiscriminately; they seek competent, prestigious, and self-similar individuals, sensitive to context and content (20:46).
  • Bias toward domains like food, animal danger, and social norms.

---

6. Gene-Culture Coevolution

• Definition: Cultural practices create environmental pressures that drive genetic evolution, and vice versa.
  • “Cooking... allowed our body to reduce the size of our guts... but then we became addicted to and rely on cooking.” (22:30–24:07)
• Human Brains and Childhood:
  • Helplessness and long childhood evolved to facilitate intense cultural learning (24:46).

Controversy and Consensus

• The framework is increasingly accepted; debate lies in specific mechanisms (27:00).

---

7. Classic Case Study: Lactose Tolerance

• Widespread Misconceptions:
  • Lactose intolerance is actually the historical norm; persistence of lactose digestion into adulthood only appeared in dairy cultures.
  • U.S. government campaigns for milk consumption neglected this, leading to health issues (28:24–30:30).
  • “If we had spent more time trying to get the science right and less time on the politics, we would have done better.” (29:35)

---

8. Culture as a Driver of Human Evolution

• Against the “End of Genetics, Start of Culture” Myth:
  • “Cultural evolution goes well back into the Paleolithic, deep into our evolutionary history, and has been altering our genetic evolution in important ways.” (31:28)

---

9. Dog-Human Co-evolution?

• No strong evidence for gene-culture coevolution in humans regarding dogs, though dogs have clearly evolved alongside humans (33:09–35:12).
• Childhood experience likely drives comfort or fear of dogs.

---

10. Culture and Social Norms Shape Psychology

• Norm Internalization:
  • All societies have shared norms; children rapidly assimilate these, inferring “proper” behavior through frequency and prestige, even without explicit teaching (36:39–37:40).
  • Memorable Experiment: Kids adopt and enforce modeled behaviors on their own and onto puppets (37:40).
  • “Modeling is powerful... but older kids who are the same sex as your kid are even better models.” (39:19)

---

11. WEIRD vs. Non-WEIRD Cultures

• Acronym: Western, Educated, Industrialized, Rich, Democratic.
• WEIRD Psychology is Unusual:
  • Individualism, analytical thinking, focus on personal aspirations, moral judgment based on intent over outcome, guilt over shame (41:18–43:10).
  • “The populations most commonly studied by psychologists... were often at the extreme ends of the distribution. So they were WEIRD...” (41:04)
• Guilt vs. Shame Cultures:
  • WEIRD societies emphasize guilt (personal standards), whereas many societies root conduct in shame (social norms) (43:28–45:01).
• Self-description Test:
  • WEIRD individuals define themselves in terms of traits; others, by relationships and group memberships (46:09–47:06).
• Variation Within Societies:
  • Significant differences even within nations/regions (47:33).

---

12. Monogamy and Male Hormones

• Testosterone Studies:
  • Monogamous societies see a decline in male testosterone after marriage/childbirth; polygynous societies do not (48:22–50:28).
  • Cultural norms, not genes, can account for these physiological shifts as evidenced by immigrant and changing societies.

---

13. Testing Genetic vs. Cultural Causes

• Assimilation Studies:
  • Immigrants’ values shift across generations, supporting cultural over purely genetic causation for psychological traits (51:17).

---

14. Culture’s Power in Multiethnic Societies

• Persistence of Cultural Differences:
  • Groups (e.g., Protestants vs. Catholics in Prussia, Jews in Europe) maintain distinct cultural traits—including literacy and norms—despite geographic proximity (52:29–57:20).
  • Language, dialect, and endogamy serve as “ethnic boundaries” that maintain separation.

---

15. Policy Implications & The Collective Brain

• Importance of Culture in Policy:
  • Most policy ignores culture, assuming universal rational actors.
  • Institutional transplants (e.g., U.S. judicial system in Japan) may fail due to local psychologies.
  • “Most policies are psychology blind... they’re culture blind.” (57:47)
• Innovation from Diversity:
  • Diverse, interconnected populations foster recombination of ideas—a prime driver of innovation.
  • Immigration plays a crucial role in national creative capacity (59:35–60:08).

---

Notable Quotes & Memorable Moments

• “We’re a species that’s addicted to culture in ways that other species who have some culture really aren’t.”
  • Joseph Henrich (13:28)
• “Humans evolved to put faith in these traditional practices ... We’re much more willing to pay costs, do it the way we’ve been taught, than other species are.”
  • Joseph Henrich (18:30)
• “If we had spent more time trying to get the science right and less time on the politics, we would have done better.”
  • Joseph Henrich, on milk campaigns and lactose tolerance (29:35)
• “The populations most commonly studied by psychologists ... were often at the extreme ends of the distribution. So they were WEIRD...”
  • Joseph Henrich (41:04)
• “Most policies are psychology blind ... they’re culture blind.”
  • Joseph Henrich (57:47)

---

Timestamps for Important Segments

• 03:29 Introduction to Henrich’s academic journey and early dissatisfaction with anthropology
• 05:13–08:25 The science of culture’s impact on biology and psychology
• 09:21–10:16 How literacy reorganizes the brain
• 11:24–14:51 Human intelligence vs. inherited cultural knowledge; role of imitation
• 15:33–19:59 Deep wisdom in seemingly arbitrary tribal traditions (manioc, corn)
• 22:26–26:50 Gene-culture coevolution and childhood as a learning window
• 28:24–30:30 The history and consequences of milk consumption
• 36:39–39:19 Social norms: internalization and the powerful role of modeling
• 41:04–43:10 The WEIRD phenomenon and its psychological implications
• 48:22–50:28 Monogamy, polygamy, and testosterone—cultural impact on biology
• 57:47–60:08 Policy implications and the synergy of collective intelligence

---

Conclusion

Joseph Henrich’s work provides a powerful lens for understanding human uniqueness, emphasizing that culture is not a veneer on biology but a dynamic evolutionary force shaping who we are—individually, socially, and even physically. This episode offers rich food for thought for anyone interested in how invisible traditions, social learning, and the legacies of our cultural ancestors continue to shape the world today.

Transcript

[A]

SA welcome to another episode of Conversations with Coleman. If you're hearing this, then you're on the public feed, which means you'll get episodes a week after they come out and you'll hear advertisements. You can gain access to the subscriber feed by going to ColemanHughes.org and becoming a supporter. This means you'll have access to episodes a week early, you'll never hear ads, and you'll get access to bonus Q and A episodes. You can also support me by liking and subscribing on YouTube and sharing the show with friends and family. As always, thank you so much for your support. Welcome to another episode of Conversations with Coleman. Just one announcement before I introduce my guest today. People who subscribe through my website will now have access to transcripts of season one of my podcast. So if you prefer reading to listening, then that's one of many reasons why you should [e-mail] all right, my guest today is Joseph Henrich. Joseph Henrick is a professor of evolutionary biology at Harvard University. He's also taught psychology and economics at the University of British Columbia and anthropology at Emory University. This episode is all about the power of culture. We talk about the ways in which cultural practices have shaped human biology. Joseph explains why culture is the real reason why humans dominate over the animal kingdom. We talk about the implicit wisdom in many tribal cultural traditions. We talk about lactose intolerance and other ways that culture has interacted with genetics. We talk about how cultural differences between groups can cause measurable psychological differences between them. We talk about so called weird cultures and how they differ from more traditional cultures. Weird standing for Western, educated, industrialized, rich and democratic. We talk about how monogamy changes male hormones and much more. So without further ado, Joseph Henrich. Okay, Joseph Henrich, thanks so much for coming on my show.

[B]

Yeah, good to be with you.

[A]

So I've been a fan of your writing for many years. I think when I was an undergrad philosophy major, I wrote a 20 page term paper about the group selection versus individual selection argument. And that's where I was introduced to a lot of your writing on the subject.

[B]

Okay, great.

[A]

Yeah. So in preparation for this, I read your most recent, I think your most recent two books, the Secret of Our Success and the Weirdest People in the World. And I think these are fascinating texts and before we dive into them, I just want to give my audience a sense of who you are and how you came to be interested in the subjects that you study.

[B]

Okay. So I'm Joe Henrick. I'm a professor of human evolutionary biology at Harvard University, and it's kind of a long story is how I got interested in these topics. But when I decided to go to graduate school in cultural anthropology, I gradually, in my early years of graduate study, became dissatisfied with what anthropology had to offer in terms of explaining human behavior and human psychology and the diversity of behavior that I was seeing across societies. As I was beginning to do field work in the Peruvian Amazon, I began to explore what other fields had to offer, including psychology and economics. I began to work with Robert Boyd, who was building mathematical models of cultural evolution. So I learned more about those and then really began to take an evolutionary approach to human behavior, but thinking keenly about how humans are a cultural species heavily reliant on learning from other people, and how that can be integrated into an evolutionary approach.

[A]

So it's hard to know exactly where to start. I think much of your writing centers around the power of culture, which can sound like a platitude, I think, and something that almost nobody would deny. But to maybe sharpen up really why your work is so interesting. Can you talk about the views of culture's effect on human psychology that sort of the alternatives to your viewpoint that you are arguing against, to sort of emphasize the extent to which your work on the power of culture is not. It's much more than one would assume just from hearing that sentence for the first time.

[B]

Yeah, I mean, I think it's important to realize that until recently, disciplines like economics and even in my own field of cultural anthropology, where you would think that culture would be a core and important part of explaining human behavior, culture's often sidelined. So, for example, standard economic models take no account of the idea that people might acquire different preferences or have different beliefs as a consequence of growing up and being exposed to different environments. And even so, I was, I started, you know, working in a subfield of anthropology called economic anthropology. And really they tried to explain the differences in people's behavior based on, you know, material constraints. Kind of, kind of Marxist in that sense, Marxist materialist. And didn't really have what I would call a theory of culture. So how do we explain the emergence of cultural patterns, cultural persistence, all that kind of thing? So we're really trying to put a science to culture and to kind of make it something that we can build models of, explain things like the origins of social stratification, things like innovation and what I call cumulative cultural evolution, and then thinking about how that then shapes our genetic evolution. So culture has this long term shaping Our physiology, biology, brains, where many of our human unique adaptations are actually responses to features constructed through cultural evolution. So things like fire and cooking are products of cultural learning transmitted over generations. And this then affects the genes that shape our intestines and all kinds of aspects of our physiology, just to give you one example. And then I make the case that this also affects aspects of our psychology. So we can't think of our brains as products of evolution without recognizing that a lot of our brains are actually a response to this growing body of cultural know how to the creation of social norms, to the need to adapt to diverse institutions. The other way in which this is important and under recognized is a push away from this dualistic tendency where people tend to think of biological or genetic explanations on the one hand, and cultural learned explanations on the other. But it's to realize that when we learn something, we're actually changing the physical structure of our brains so that we have different brains at the end. So it means that cultural evolution is a kind of biological evolution, just not a kind of genetic evolution. And getting people to understand that difference between genetic evolution and broader forms of biological evolution, which includes cultural evolution, is difficult because we tend to divide the world into these two kinds of things. So the one example that I give in the Weirdest People in the World, I think I also deal with it in the Secret of our Success, is something like reading. So when you learn to read, you get a thicker corpus callosum. That's the information highway that connects the two halves of the brain. And you get specialized circuitry in your left hemisphere. So your brain changes organically. Right. It's physically different than it was before, it has different processing abilities, it looks at the world in different ways. But this is purely a product of the cultural evolution of a certain value, say becoming literate as a child. And for most people, that's something that's spread only in the last few centuries. So that was biological, non genetic evolution that's occurred in the last 400 years or something.

[A]

I want to underscore that last point because the phrase changes your brain is one of these TED talk cliches that can mean two different things. It can be, you know, something can change your brain in the trivial sense that any memory has to have some mark on your brain to be a memory. But the kind of brain changes you're talking about are non trivial brain changes. So the one about literacy as you write in your book, most cultures throughout history have not been literate and just the experience of learning to read a language as A child not only changes, makes brain changes associated with being able to read, but changes the location in your brain responsible for facial recognition, which would seem at face value to be totally unrelated to reading. Is that right?

[B]

Yeah. And it does other psychological things besides change your facial processing. But that's an interesting one because it points to some problems with the science in that, you know, neuroscientists first look at brains and they see that people tend to process faces in the right hemisphere. But it turns out they were studying almost exclusively people who were literate or entirely people who were literate at the time. And so it's literacy that induces a stronger right hemisphere bias in facial processing. Non literate people are much more equal symmetrical in their facial processing. And it's because the letter recognition machinery, that's got to be etched into the brain to make us be able to rapidly read, you know, really good readers read kind of effortlessly and automatically, even unconsciously. It crowds out some of the, some of the facial recognition circuitry and uses it, you know, reuses that neural geography.

[A]

For letters and therefore makes literate people slightly worse at facial recognition.

[B]

Yeah, yeah. I mean, so, you know, this, some of these studies are still a little bit, you know, I'd like to see more replications of them, but at least some studies suggest that, yeah, learning to read makes you worse at facial recognition.

[A]

Wow. So in the Secret of Our Success, you start out by framing the discussion around how much more similar we are to apes in our individual competency and intelligence than we think. This is surprising, but very plausible. And you make the case that really humans are not, you know, what makes us stand out from the other apes we're related to is not our intelligence as individual nodes, but the vast legacy of cultural knowledge that we inherit without realizing it. So can you talk a little bit about, can you do a little bit to undermine our confidence as humans that we're so much smarter than apes as individuals?

[B]

Yeah. And there's a few different lines of evidence that I use in the Secret of Our Success. The first is just comparative experiments. So Esther Herman and Mike Tomasello and their colleagues and subsequent studies have just taken human children, mostly German children in this case, and compared them to other ape species. So chimpanzees, orangutans, and looked at them on a battery of 18 different cognitive tasks. And sometimes the humans edge out the chimpanzees, sometimes the chimpanzees edge out the humans. So in the case of tool using, chimps are a little bit better than children. But then the Place where humans really shine. And it's almost difficult to design a test where the apes aren't at floor and the humans are in ceiling is in imitation tasks. So anything that involves social learning, the young children seems to be what Mike Tomasello calls imitation machines. So they immediately and unconsciously automatically copy other members of their social group. They can mimic body patterns, copy goals, do all this kind of good stuff. So we seem to be cultural learning machines and we don't seem to have better numerical cognition, at least right out of the box compared to other apes. Now of course as adults, any adult would mop up the floor with the apes on all these different kinds of numerical and spatial cognitive tasks. But a lot of that is because we're acquiring pre built solutions like using numbers. So the reason why these researchers are using children is because those kids are going to go to school eventually and they're going to learn to count without bound. They're going to learn all kinds of, they're going to learn left and right, which is going to give them spatial abilities. So it's a download of cultural information that allows them to outperform the aids, at least partially so. And that really comes out in these tests. The other point I'd like to make to people in making this point is that there's lots of cases where humans have been stranded, lost European explorers find themselves over, over history in places where hunter gatherers live very well, have no problems getting food. But they themselves, using their human instincts and their human intellects, can't figure out how to find food or make shelter or even travel. Sometimes they can't make the relevant boats or whatever to travel. And it just shows how helplessly we are when we aren't equipped with this large body of inherited cultural information. So we're a species that's addicted to culture in ways that other species who have some culture really aren't.

[A]

Yeah, I think that that point again is worth dwelling on. What marks humans apart from pretty much every other species is just our, the, the huge distance between what we're able to do as a result of inherited cultural knowledge and what we're able to do simply as individuals. Right. There's really nothing in my apartment right now that I know how to build or could learn how to build completely on my own, even in my whole lifetime, I think. Right.

[B]

And so that's in some ways that's the secret of our success and that it's not that individually we know how to figure out each of those things, it's that as a species by sharing Information across minds. And over generations we're able to accumulate a body of knowledge and a division of information that allows us to produce these increasingly complex, you know, technologies are the obvious ones, but then also institutions and languages and all these other cultural products that no single individual. Imagine trying to design English grammar or something. It's the product of a long cumulative cultural evolutionary process.

[A]

Yeah. So you have some of these really amazing examples in your book. And this connects to the point about lost European explorers of cultural practices that are passed down in tribes where no one in the tribe really knows why they're doing it. But there's an implicit life saving wisdom in the practice that's more accurate than, than any individual could possibly come up with. And I think one of them relates to manioc, if I'm not pronouncing that wrong. Yeah. Can you, can you tell one of those?

[B]

Yeah. So just as background. So manioc is this root crop that is a staple food in lots of place in the tropics. It was indigenous to South America. And there's a, not sort of broadly speaking, I mean there's actually a continuum, but broadly divide types of manioc or cassava into sweet manioc, which you can just, you know, eat right away, it's not poisonous. And bitter manioc, which contains cyanide. Now the cyanide is an adaptation that allows this particular type of cassava to grow in certain kinds of soils that are otherwise not very good for crops. But then you can't eat it because. Or it would be bad for you if you ate it because it contains this cyanide. And it can either contain high levels which could kill you, or it could contain low levels which you might not detect and then could accumulate to give you some chronic disease later in life. And so especially when populations are dependent on it, it's crucial to get most of the cyanide or all of the cyanide out of it. So populations in South America develop these processing techniques where they grate it and they rinse it and they soak it for a period. There's a certain amount of waiting time. And then they can make bread out of it or make some other kind of food out of it, and this removes the cyanide. Now, populations often know which steps are crucial and which steps are not. So this is just a cultural set of practices that's emerged that protect these populations and allow them to rely on this valuable crop. And then we had this kind of natural experiment that occurred when Portuguese explorers began taking bitter manioc to Africa. And folks there didn't evolve culturally, hadn't had it for thousands of years like the South Americans did. But it rapidly spreads into places that you can't plant anything else and people become dependent on it. But then you get all these diseases as a consequence of the buildup of this cyanide over decades sometimes and creates a big public health problem. And so then public health people even today are trying to persuade populations to make sure they fully detoxify their cassava. So that just illustrates that it's something that's hard to figure out.

[A]

Yeah, it's hard to figure out. And even the people successfully doing it don't really know why they're doing it.

[B]

Right.

[A]

That's like the key. What makes it so interesting to me is that as you point out in the book, any individual South American reasoning on their own might rationally come to the conclusion that we don't need to spend as much time preparing this manioc.

[B]

Right?

[A]

We can, we can just. Nothing bad happens even in the short or medium term if you just spend half as much time. We could save a lot of time here, guys, and they would seem to have a totally coherent argument, but they would be missing the fact that over the course of 40, 50 years of taking a shortcut, you have this long term buildup of cyanide. And if they had just had faith in the practice of their elders, they actually would have come out of that much more healthy.

[B]

Right. So it's a case where I argue that humans evolved to put faith in these traditional practices that get passed down. It doesn't mean they never deviate from them, because of course we do. But compared to other species, we're much more willing to pay costs, do it the way we've been taught and our predecessors have done it than other species are. I mean, another interesting example along these same lines is corn. So populations in the America that rely on corn as a staple, corn is missing some crucial amino acids. And as a staple, if you rely on only that, you'll get a horrible disease called pellagra. And so when Europeans began taking corn over to Europe, they didn't. So anyways, you need one other piece of information, which is that to deal with this, the pre Columbian populations of North America would include ash or burnt seashells in their cornmeal as a way of breaking open and freeing the otherwise unavailable amino acids and niacin specifically. And this solved the nutritional problem. Then when Europeans took this over to Europe, they didn't take any of those practices. Populations of poor people that became dependent on corn Got this horrible disease called pellagra, which is this lack of niacin. And it took, you know, scientists were trying to figure it out, they couldn't figure it out. Finally, an American named Goldberger figured it out. But even he had a terrible time trying to convince the scientific establishment.

[A]

We deserve to know what we're putting in our bodies and why, especially when it comes to something we take every day. Ritual's clean, vegan, friendly. Multivitamin is formulated with high quality nutrients in bioavailable forms your body can actually use. Yeah. So let's talk a little bit about how humans acquire culture. At one point in the book, you talk about the who, the when and the what of cultural learning. Meaning as we're growing, we don't imitate and acquire culture randomly. We don't just copy whatever we see. We discriminate who we copy from when we copy them. And what about their behavior or beliefs or social norms we copy. So can you talk a little bit about how we discriminate in cultural learning?

[B]

Yeah. And so there's a big picture shift here in that often people think of culture as something that adults do and they socialize children by transmitting what they want to kids. That's very much kind of a, almost a Western folk model of how socialization or culture works. The argument that my colleagues and I now, as it's kind of core to the field of cultural evolution, is that children, humans have evolved to be very selective about who they pay attention to, what kinds of information they're particularly interested in, and when they use different kinds of learning strategies. So the who is kids tend to pay attention to particularly successful, competent, prestigious individuals who match them, say on sex or share their language, speak the same dialect, things like that. So there's sort of skill, kind of competence related cues. And then there's also self similarity, similar to the roles in future life that I'll occupy. And so these things help kids triangulate in on individuals likely to possess useful or adaptive information skills, ways of interacting, motivation strategies, all that kind of stuff. Then there's the what. People seem to be interested in certain domains. So something like the prevalence of cooking shows shows that people everywhere seem to be interested in food. Kids are often interested in the details of different kinds of animals, but they're particularly able to learn things like about the dangerousness of animals. So we're biased to certain kinds of content and topics. And then when there are some times like under uncertainty when it's really useful to just copy others, and other times where problems are low Cost and things are relatively easy that you might rely more on individual learning instead of social.

[A]

So what is gene culture? Co evolution?

[B]

Yeah, so that's the idea that I was describing earlier, where there's a cultural evolution produces some body of information or some product that then shapes our genetic evolution. So one example I gave earlier was the spread of use of fire for cooking. Cooking basically pre digests food and makes it easier for our digestive systems to process it. So it softens it, it denatures proteins so that we don't need as much stomach, as big a teeth, as tough jaws, and we can have shorter colons for something like starch. Processing and that allowed our body to reduce the size of our guts and reduce our overall genetic system. But then we became addicted to and rely on cooking in order to break down our food and kind of pre digest it. So we're co evolved with cooking as a species. And then I argue there's a whole bunch of things like that. The sort of biggest idea in the book about this is that in one sense our brains expanded because they needed to acquire, store and organize a growing body of cultural information. So as cumulative culture began to produce fancier tools where you had to know how to make them, knowledge about medicinal plans for staying healthy, knowledge about the ecology and which species and what you had to detoxify, like the, like the bitter manioc or the corn. You then needed a bigger brain that was allowed you to look out into the world and learn from others. That because that's where the action was, you had to be able to acquire this body of valuable adaptive information. And this creates an autocatalytic process which expanded our brains rapidly. So over about 2 million years, our brains triple in size.

[A]

Yeah. I think there's a few things to underscore how important this point is. One is that earlier when we were comparing toddlers to chimpanzees, one thing to note is that this is precisely the reason that human babies are born so helpless and undercooked, basically relative to every other ape. Which just reflect, I think we take for granted the fact that a three year old chimpanzee is pretty much like a full fledged chimpanzee.

[B]

Right.

[A]

We have the same common ancestor, but the way our species went is that by three years old you're still largely helpless. Right. And obviously that's a huge penalty to pay in the survival game historically. But the upside of that is the less baked you are, the more time you have to absorb particular cultural knowledge of a particular location and particular time. That's precisely what the helplessness of human youth gives you that the competence of chimpanzee youth doesn't give you. And the measure of how helpless we are is the measure of how useful it must be to have that cultural knowledge.

[B]

Right, exactly. And so there's two key ways. So there's the fact that human babies are born, in a sense, premature relative to other apes. So they come out particularly helpless. They can't even hang on to mom. Mom has to do extra work to get them nursing and whatnot. And although their brains are still active, so even when they're in the womb, infants are beginning to learn the dialect of their language, listening to mom talk. And then they begin immediately doing some amount of cultural learning right out of the womb. And by one year of age, they're off and running in terms of cultural learning. And then the other interesting feature of human life history is that we have this extended period of middle childhood where we become really good learners. So this is like 6, 7, 8 years old. Other primates seem to have this. And so we're great learning. We're learning social norms. Kids are beginning to internalize the rules of navigating the social world, but they have small bodies. So the idea here is that natural selection is giving us extra time for to load up those brains with all the cultural knowledge, but not giving us a lot of caloric demands. So by keeping our bodies small, we don't cost that much, but yet we can do all this learning. And then we hit the adolescent years and we get big and we start basically apprenticing during the adolescent years and then eventually become adults.

[A]

So is your conception of gene culture co evolution controversial in your field? And is it becoming accepted? What's the status of it right now?

[B]

Yeah, I think it's definitely becoming accepted. I mean, so it used to be that back when I started in the 90s, it was considered, people would say, oh, that's a very interesting theoretical idea, but really back then there was only one good example. This, this gene culture co evolution that some human populations have had with dairying practices, where they have the ability to process lactose into adulthood so they can drink fluid milk and still get the nutritional benefit. Some populations haven't been exposed to these dairying cultures where they've developed cheese and yogurt processing, which means they didn't have a selection pressure on these genes that allow this lactose processing to continue into adulthood. So that was a kind of fairly well studied example of gene culture co evolution that goes back into the 1970s. But since a lot of genetic data has become available. It's clear there's been lots of gene culture co evolution over, you know, as humans adapted to different nutritional environments, different disease environments. So I think it's pretty well established that something occurred. The main controversies now are really about specifics. So, you know what? If so I make this case that we have a norm psychology that adapted to a world of social norms. Not everyone agrees with that, but that's a specific argument about a type of gene culture co evolution, not the overall idea that there's been some amount of gene culture co evolution.

[A]

Yeah, we'll get to that one. But I do want to dwell for a moment on the lactose example. I'm sure many people have heard of this one. I do think it's the most probably widely known example of gene culture co evolution. And actually you pointed this out in the book that well into the 90s and even into my youth in the 2000s, there was just a huge push for people to drink milk for health reasons, and athletes and celebrities drinking milk and having the milk mustache. And I just always noticed that if I drank milk I had a stomach ache. But it never occurred to me that I was lactose intolerant or that lactose intolerance was in fact the norm, not the exception. Right. I figured I must not have that weird thing called lactose intolerance because I've never been diagnosed as such. So I'll just keep drinking milk for 10 years and wondering why I have a stomachache every time. And I think that's a really interesting example of culture not really catching up to this thing about gene culture co evolution.

[B]

Yeah. And it's an interesting example of a case where, so going back, you know, even to the 1950s and before, when this push for people to drink milk, you know, beginning to be pushed at, you know, the national levels and whatnot, there were researchers saying that, you know, that why are some, why are some groups having this kind of these health related problems related to drinking milk? And this was ascribed to economic differences or economic disadvantage or growing up in cities or something like that. And people weren't taking seriously the possibility that there could actually be a physiological difference in the genes that people had. And so, you know, for 40 years, the US government pushed this drink milk campaign, which caused lots of populations to have problems if they didn't come from a population that had not invented cheese and yogurt processing or didn't have a history of dairying or something. So this is a case where, if we had spent more Time trying to get the science right and less time on the politics, we would have done better.

[A]

Yeah. And to put a fine point on sort of why this is interesting, at least to me, is that everyone knows the basics of natural selection and Darwinian evolution, which is that your natural environment applies selection pressures which favor certain genes and so forth. People learn this in seventh, eighth grade. The big point you're making is that human culture and particular cultures, which no one person chooses or could even create, become a new part of the environment, which then applies selection pressures in much the same way that the natural environment does. Right. Culture becomes a huge part of the environment that then shapes us genetically. Yeah, that's the point here, which is, I think, which many people don't as much consider when they're thinking about evolution and natural selection.

[B]

Yeah, I mean, I think that sort of, if there's a classical view that I can straw man or characterize here, it would be that there was genetic evolution going on in humans up to a certain point. And then we became fully human. And from that point it was cultural evolution. And so, you know, those two never meet. There was the genetic evolution period, the cultural evolution period. But what the secret of our success is that cultural evolution goes well back into the Paleolithic, deep into our evolutionary history, and has been altering our genetic evolution in important ways, ways that help explain what makes us human and how we're different from those other apes. And then we also now know it has extended right up over the last 10,000 years. So some of our best evidence of gene culture, co evolution, comes after agriculture begins spreading, because agriculture changes our environment in terms of the foods we eat and in terms of the prevalence of pathogens and things like malaria. So you cut fields in certain ways that cultivates mosquitoes. Malaria becomes a huge factor. Anybody who has genes like the genes that cause sickle cell anemia, those genes spread. That helps us understand the patterns of disease resistance and disease problems around the world.

[A]

So one question that occurred to me reading this book is about the relationship between humans and dogs. And I ask this partly because one of my least favorite things to admit about myself is that I don't really like dogs. Kind of fear them somewhat and used to fear them much more. But I know humans and dogs have been cohabitating for many hundreds, if not thousands of years. Do you know of any research that is looking for any kind of gene culture, co evolution regarding humans and dogs?

[B]

Well, it's interesting because I think I know where you're going, but I can't think of anything that's looking at co evolution in the humans. There's lots of people who are interested in the co evolution in the dogs. So in my own department, Aaron Hecht, who's a, who's a neuroscientist, is interested in the process as dogs as a model of domestication. So the argument I make in the Secret of Our Success is that humans are a self domesticated animal. You know, we've kind of beaten some of the aggression and stuff out of each other and that's led to the selection for genes that make us less inclined towards reactive aggression. My colleague Richard Wrangham has made that case and then a bunch of other kind of socio social effects. And people like Aaron are trying to study dogs to say, you know, dogs come from wolves, so we have the origin species and how do you make a dog out of a wolf? What are the processes that make that dog well, fit to humans? Yeah.

[A]

So yeah, I guess my axe to grind on this is that I've sometimes been in the position of defending my fear of dogs as rational and natural.

[B]

Right.

[A]

Given that dogs are extremely close to exactly the kind of predator that we should be built to fear.

[B]

Right, right.

[A]

And you know, they have feeling that.

[B]

And they could, you know, do real damage if they wanted to.

[A]

Yeah. And they're also cute and great companions and obviously. But I've always thought, well, the natural thing for a human would be to fear an animal that looks like that and it must be trained out of you by having a dog as a child. Right. So it's not that I have a phobia per se or something bizarre about me, but again, I can't imagine it would be important enough for humans to have evolved in the way that we evolved to process milk or the alcohol inhibition gene that you talk about and so forth.

[B]

Yeah. So it could be, I mean, it sounds like you're inclined to go with the ontogenetic process. So you grow up with dogs, they're there since you're, since you're a young kid. And they just seem like a very natural thing where if you're not, then they're big scary things. Right, that makes sense to me.

[A]

So let's talk about the idea that much like our ability to process milk, social norms themselves can shape our psychology, rewire our brains in the non trivial sense and create psychological and behavioral differences between different cultural populations. What is the most persuasive evidence for this?

[B]

Well, it comes from, I think, studies of, well, first of all, social norms seem to be a human universal. So I mean, nobody's ever encountered a society where they didn't have mutual so widely agreed upon, widely shared behaviors that most people adhere to and for which deviation from causes other people in the group to think badly of you. The next is how quickly children learn this. So from a very young age, children will spot high frequency behaviors and then assume that if they violate those, that that's somehow going to cause others to think badly of them, even if they don't see anyone react negatively. So there's lots of research in the laboratory showing that when children see a high frequency behavior, they immediately assume, even in one, even in a single shot trial, if someone pays a cost to do something, they'll assume that you're supposed to pay a cost to do that thing. And if you don't, then you can suffer some kind of reputational consequences. So it seems like kids are bringing something into these learning experiences from a young age.

[A]

So I think you mentioned an interesting example with an M and M experiment where children copy the standards they see modeled around them even when nobody's watching.

[B]

Yeah, I mean, there's a lot of experiments like that in which. So there are these experiments that involve this puppet in which the individuals will watch an adult. And oftentimes the adult is not even looking at them and doesn't know the kid's watching. They'll do something in a certain way and then the kids will have a go at it. And they'll see that the kids try to imitate often the adult that they saw who's no longer in the room. And then a puppet will appear and try to do it, and the puppet will do it differently than the adult that they proved that the kid first saw do it. And then the kid will object and try to correct the puppet. So the kid not only saw that this is a way to use these objects, but inferred automatically and unconsciously perhaps, that that there's a proper way to do these things. And the puppet is now violating those things. And they'll scold the puppet.

[A]

Right. And even more interestingly, I think in the bowling experiment I'm now remembering, the adult had a certain standard for what it meant to bowl well.

[B]

Right, right.

[A]

And the child, when the adult was no longer in the room, adopted that same standard and would only reward itself if it exceeded the standard that it had just seen the adult hold themselves to.

[B]

Yeah, yeah. So that's a great experiment. Those actually experiments go back into the 1960s. So a simple bowling task where or other game where the kid has to do something and if they get a certain score, there's freely available snacks like M&MS. And the kid watches one of a number of different models. And the simplest way to describe it is there's one situation where the model has to get a score of, you know, 10 or something, a high score. And if they get above the 10, then they take some M&Ms. And the model often says something like, oh good, I got a 10. So I'm allowed to reward myself with these M&Ms. And take them. And then there's the low standard model, who does it at three or something. Oh, I got above a three, I can reward myself and the kid. Not only they copy the standard for rewarding themselves. And then the question is, well, the kid's just doing it to go along with the adult because they want to impress the adult. So the adult leaves. Now the kid's by himself being watched through a mirror or videotaped or something, and the kilt still seems to adhere to the higher or lower standards, or at least it's statistically detectable that they're being influenced by this model observation.

[A]

Yeah, that's the kind of experiment that parents probably love to hear because it definitely gives you a sense that you have more control over how your kids turn out by modeling.

[B]

Yeah, modeling is powerful. And the only though the cultural learning literature would give you some other cues, which is it's good as a parent you can be a model, but older kids who are the same sex as your kid are even better models. So kids like to learn stuff from somewhat older kids. So if you got a five year old and you want to train them up, you need a good quality 8 year old for them to learn from. Right.

[A]

So let's talk about the difference between weird and non weird populations. The acronym weird, can you explain what this means and why it's interesting?

[B]

Sure. So that's an acronym that my colleagues Steve Heine and Ar nor Zion and I coined in 2010. And it stands for Western educated, industrialized, rich and democratic. And we coined it when we were making a critique of the experimental behavioral sciences, including psychology in particular. And what we had done is. Well, first we noticed that most studies in psychology and allied disciplines were done with American subjects or university students in Europe, not sampling very broadly across the species. And then those results were often taken to be representative and written up as if people do this or people think this particular way. So we surveyed the available evidence and found that not only was there substantial more variation, psychologically speaking, than you would have gotten from reading psychology textbooks, or even leading journals, but that the populations most commonly studied by psychologists and other researchers were often at the extreme ends of the distribution. So they were weird, so they were psychologically unusual. So as a way of raising researchers consciousness about this methodological problem, we call these populations the weird and use the acronym.

[A]

So can you talk about why in what ways weird people differ from non weird? And probably the vast majority of listeners to this podcast would fall in the weird category, right?

[B]

Yep. So one thing that's probably the best studied dimension for this is individualistic. So very focused on themselves, trying to cultivate individual attributes or dispositions, concerned with their own accomplishments, overconfident, tending to think of themselves as a unitary self. Lots of experiences of guilt relative to shame. And then potentially related to this, but potentially independent is a tendency to think more analytically versus holistically. So analytic thinkers tend to break things down into its parts, assign property to those parts, and use that to explain the behavior of things. People who think holistically look at the relationships between things and the background context to explain things. So if you think about physics, physicists break things down to little itty bitty particles and then assign properties to those particles. And then when that breaks down, they go to even smaller particles and they assign properties to those particles. What psychologists do is they assign personalities to people. These are, you know, dispositional traits to individuals. Economists assign preferences. So those are, those are analytical thinking. If you were to think and do that from a kind of holistic point of view, you think about the relationships between people and not focus on the dispositions. There's also a tendency to use intentionality or other mental states in making moral judgments. So if somebody steals something, if you're weird, you tend to be concerned about, well, do they mean to steal it or do they take it by accident? Same thing with something like murder. Intentionality plays a big role. But in the studies I present in the Weirdest People in the World and have done work with Kami Curtin and others, we find that actually there's quite a bit of variation. Clark Barrett. Quite a bit of variation in people's tendency to use intentionality or other mental states in judging others. So those are just three examples. Another would be cooperation with strangers. Seems to vary a lot.

[A]

Yeah, I think the glossed over it, but the difference between guilt and shame I think should dwell on a little bit. By guilt you mean? Yeah. Can you talk about what you mean by the difference between those and how weird people, why we people?

[B]

I think one of the traits of being weird is kind of getting all guilt and shame kind of confused. So shame is that emotion you experience seems to be a human universal when you violate a shared norm. So you've fallen in the eyes of the community and the eyes of others, in the eyes of people you respect because of this violation of the norm. Shame in many societies is also contagious. So if someone close to you in your social network, say your, your son or your brother, violates a social norm, you actually get shame. You experience shame because of what they did. And people will also think badly of you because of what your brother did in lots of places. So anthropologists and others have long talked about shame society. So social life is governed by shame. Guilt is different. It doesn't seem to have the kind of body signals that you have with shame, which is this low kind of head down, make yourself small, look that we actually see kind of the predecessors of this in non human primates. With guilt, it's your personal standards. So it's not a social thing. So you might have a personal standard that you go to the gym every day. Your neighbor is not going to judge you if you skip the gym and take a nap on a particular day. But you might feel guilt about not going to the gym because you set a personal standard and you're aspiring to that standard. And the idea is that guilt is an important emotion or affective state that helps get, helps you pursue your own goals, and it's very much a personal thing. Now, of course your own goals are going to be influenced by the demands of your society, but it's not the sense that everyone's judging you. It's much more about you judging you.

[A]

Yeah. So weird people are much more likely to live in a culture of guilt than a culture that really values shame. And I think we can. I can definitely see this in America. Right. You're not really supposed to. Shame is really like an illusion.

[B]

So shame societies tend to have a lot more norms to violate, and so you're more likely to break them. You're more cautious in that sense. More individualistic societies tend to get rid of a lot of extra norms. And so there's fewer norms to break. And it's more about individual aspirations and failures to achieve those.

[A]

And there's one really interesting experiment where you ask people just to complete the sentence I am blank.

[B]

Right? Yeah. So this is widely used by social psychologists to get at the concept of.

[A]

And maybe actually before you describe it, I just want to invite my listeners to. If you have to complete the sentence I am blank without just saying Your name, giving something about who you are, what's the first thing that occurs to you? Just think about it. And now you can describe the experiment.

[B]

Okay, so you have to answer this in 20 different ways. And then psychologists will code the different ways that people answer. And so I say in the book, I might answer by saying, I am curious. I am a kayak or I'm a scientist. And so all of those tell you things about me and what I care about. But I didn't answer it by saying I'm Jessica's father and various other relationships, Ross's brother. And because those would tell you more about my relationships and less about my aspirations and accomplishments and things like that. So when you go around the world and you code how people in different societies ask this, you range from American undergraduates who give you almost all, or sometimes all things like, I am curious, I am a fast runner, things like that, as opposed to the relationships, what sort of core groups you're in, things about your family and whatnot. And so this just varies a lot.

[A]

Across societies, and this also varies a lot within countries. I think most people would recognize the American south to be historically more a place where you might identify yourself by what family you belong to, at least relative to the Northeast, for instance. And I imagine on many of these dimensions, you're going to find big variation just within a single country.

[B]

Yeah, that's for sure. And that's one of the things I really emphasize in the book. So various chapters, I look at variation within China, just looking at different provinces, variation with India. And I have a big section devoted to variation just within European countries, including just within Italy. My lab is actually now working on a kind of US Focused project where we're able to quantify some of these differences across U.S. counties. And so we can compare counties and look at the history of those counties and look at things like whether they're more morally universalistic or more morally parochial. Just comparing Americans with Americans, and you see lots of interesting patterns of variation.

[A]

So there's an argument relating to the effect of monogamous marriage on hormones in the book. Can you talk about that?

[B]

Yep. In the book, I had many more examples that are that showed how culture affected biology without affecting genetics. And so I gradually extracted most of those I left in the reading one at the beginning. And this is my other core go to example in the book. And so key background information, I think, comes to us by studies of other species. So if we look at birds, we look at the mating systems of different bird species, lots of bird species you have a monogamous pair bonds between a male and a female, where the male participates and helps contribute to caring for the eggs and then feeding the chicks and whatnot. So you have male parental investment in the babies. And when researchers have tracked the testosterone of monogamous birds, it looks like the males get a surge of testosterone, they go out, they find a mate. After they've mated, the testosterone declines and then goes down and they then invest a lot. Some birds are polygynous, and in those species, the testosterone goes up, the male goes out, finds a mate, might get her pregnant, have eggs and stuff, but it's still looking for other mates. So its testosterone stays high and it might then find subsequent mates. The evidence from humans looks like humans can adapt to that pattern as well, except within the same species. Some societies have normative monogamy where the social rules mean that males can only have one wife at a time. And when those males get married, we have evidence, good evidence, that testosterone declines, but then often declines again with the first child. But that seems to be confined to monogamous societies. Most societies over human evolutionary history have permitted high status males to take additional wives. And when we study the testosterone dynamics in other societies and polygynous societies, male testosterone doesn't decline after marriage or after the first child. Often there's not very much childcare for fathers in those societies. And if in a polygyrous society, you're looking for wife number two after you get married with wife number one. So it makes sense in the bird sense that you're out looking for additional mates so your T levels stay high.

[A]

So how do we know that all of these differences aren't just all genetic rather than cultural?

[B]

Yeah, well, so, I mean, what we can do is study immigrant populations and study populations that have changed over time. Some of the best work on the effects of monogamy have been done in the Philippines. But the Philippines was quite polygynous until Christian missionaries arrived there. So we know that the results that are similar for monogamy that we get in the Philippines look just like Americans. The same results that we get among European descent Americans. But there's these two different histories. Right.

[A]

And then also the same question. How do we know that the wider array of differences between weird and non weird peoples are not genetic?

[B]

Yeah, I mean, there's a series of lines of evidence there, but I mean, the best one comes from the assimilation process. So you can look at the effects, for example, of these psychological manipulations on, say, students who come to the US from different places and are then tested and then you can look at how long they've spent in the US and you can see that the effects get weaker and attenuate over time. It may take generation or two before they're completely invisible. And they, you know, people merge to be the, you know, indistinguishable from the majority. But you can see the decline over time as people acculturate to whatever society they're in.

[A]

Yeah. So I want to talk about the implications of this research. I mean, it seems to me one of the implications is that in a multicultural society you can have cultures that, despite living very close to each other, maintain different sets of social norms. Right. And I think one of the historical examples you gave was the Protestants and Catholics in Prussia and the difference in literacy between those two groups simply as a result of having different religious beliefs.

[B]

Yeah, yeah. So that is a great example and well studied by some economists, Becker and Woeman. And so the story there is, you know, the Protestant Reformation hits, you know, assigned the date of 1517. So Martin Luther perhaps apocryphally nails his 95 theses to the Wittenberg Church. And then Wittenberg becomes the center of Lutheranism, of Protestantism in the Prussian context. And so you can predict at least some of the variation in the tendency for these German speaking Prussian populations to become Protestantism based on how close the place is to Wittenberg. And this creates a kind of natural experiment where you can look at the degree to which distance from Wittenberg predicts literacy, you know, in the 19th century, when that, when rich data on literacy and schooling becomes available. And so there's a strong relationship between that and the reading. And if we then take that to the neuroscience evidence on reading, we can say that the adoption of Protestantism, with its importance for every individual reading the Bible for themselves, you know, and having this kind of experience of reading the Bible central to Protestantism in a way that it's not Catholicism that then is shaping people's corpus callosa. And, you know, the things we talked about that reading shapes.

[A]

Yeah. And I've heard similar arguments made about Jews in certain contexts in Europe maintaining a very separate culture of reading the Torah and and so forth, and living in the same exact locations as other groups with different cultures.

[B]

Yeah. And so this is a case where I think the ideas that I develop in the Secret of Our Success are the most useful because there we talked about figuring out who you're going to learn from and interact. So building on research done by Richard McElrath and Rob Boyd and others, I lay out the Case in the Secret of Our Success, putting a variety of lines of data together, including work by developmental psychologists arguing that one of the things that learners do is they're looking for people who have ethnic markers. So the classic ethnic marker is something like dialect or language, what language you speak. And they preferentially interact with those who share their dialect or language. Both interaction because they know they're going to coordinate social norms and also for learning, because if you're a young learner trying to make your way in the world, you need to learn from those who you're most likely to interact with, and so you're going to learn from those who share your dialect. So you can have two populations living side by side. But if they're using these cues to figure out who to interact with, then they can persist and remain different for long periods of time. And then of course, things like marriage norms can have a big effect. I mean, the biggest, quickest way to dissolve ethno linguistic boundaries is marriage across them. But lots of groups have endogamous norms, meaning endogamous within the tribal or ethnoling linguistic boundary. And that course can be set up and reinforced by laws and all kinds of other things. But as those break down, those tribal divisions will dissolve. But the basic machinery of cultural learning creates this sort of tribal ish phenomenon.

[A]

Yeah, so one of the implications of this, or so it seems to me, is that culture alone is powerful enough to produce different results for different groups. So long as they are actual, the cultural differences persist through time, right?

[B]

Yeah, absolutely. And just coming back to the Jewish example, one of the things that used to be in the weirdest people in the world that got left on the cutting room floor in order to make it a manageable size is that there is this great case. So I argue in the very beginning of the book that Protestantism begins the process of making literacy a human universal. So literacy has been spreading across the world since 1517. And you know, at least in the beginning, it was largely driven by religion. Now we see it as kind of a human right and part of universal schooling, all that kind of stuff. So this, this, it's transformed a bit. But there was one other group where almost the entire male population was literate, and that was Jews. So after the destruction of this, this, the second temple, so 70 AD, Judaism moves from being a temple based religion to a book based religion. So all men, as a matter of social norms, have to learn to read the Torah for themselves. This is a big task because most people are farmers. And so you're Taking time away from farming to study this ancient language. It's not a good economic move because Hebrew is not the language of trade or anything. You would have learned Greek or something. But this became a religious commitment, and this gave these Jewish populations an advantage in moving to the urbanization that came with the Muslim conquests and, you know, eventually makes Jews an urban population where they're affected by markets and these other cultural evolutionary things that I discuss in the book. But then the whole ethnic thing and the religious thing allows them to, you know, maintain a separate identity different from the populations that they're side by side.

[A]

So I will. I will let you go in a moment, but before I do, I want to ask if there's any policy implications that jump out at you as a result of your work. Are there any things that you would like to see changed that are informed by sort of your deep study of the power of culture, whether that's in America or abroad?

[B]

Well, a couple of ideas. One is that. So we started off discussing, you were mentioning that kind of everybody agrees that culture matters, and that's not the way policy is done. So there's often an assumption that if we get the incentives right. So the economists often tell us that people respond to incentives, and that's true, except when the incentives cause them to do the opposite thing, or they just ignore the incentives. And that's because they often process the world with a different psychology. So the exact same institutions, formal institutions that were developed, say, in the UK or in the United States, get transplanted in other countries, and they operate completely differently. One classic case is the transplanting of the US Judicial system into Japan. Japan has a perfectly functioning judicial system. It just operates quite differently from the U.S. even though the formal institutions look quite similar. So, for example, Japanese are less litigious. They're less likely to sue each other. So this is just a case of the way the institution operates depends on the psychology of the people. So we need to think about this interaction between the institutions or policies we set up and the psychologies of the populations. Rather, most policies are psychology blinds in that sense. They're culture blind. And I guess the second and somewhat independent idea is the importance of the collective brain. So in thinking about what drives innovation, what became clear in my research for the secret of our success and for the weirdest people, that it's really the recombination of diverse ideas that leads to new innovations and new ideas. And so what you want to do for that is you want large interconnected populations where lots of people know different stuff. And this is all kinds of diversity, cognitive diversity, diversity of knowing different recipes, of thinking about the world in different ways. You want analytic thinkers, you want holistic thinkers. And it's this synergy of different ways of thinking that really drives innovation. So one of the things that I built on since working on the Weirdest People in the world is the degree to which immigration into the US has powerfully driven innovation. So you can trace pulses of US Innovation to either inflows of immigrants, and you can trace declines in US Patenting, for example, and citations to world wars or to anti immigration policies.

[A]

All right. Is that what you're working on now?

[B]

That's one of the things, yeah. Actually, I was reading for that this morning.

[A]

Awesome. I look forward to that and maybe having you back on to discuss that whenever that comes out.

[B]

Great.

[A]

Joe Henrick, thank you so much for your time.

[B]

All right, thanks. Good to be with you.

[A]

All right, if you appreciate the work I do, the best ways to support me are to subscribe directly through my website, ColemanHughes.org, and to subscribe to my YouTube channel, so you'll never miss my new content. As always, thanks for your support.