How do we learn? Usually from experience, of course. Maybe we visit some new place, or encounter a new tool or trick. Or perhaps we learn from someone else—from a a teacher or friend or YouTube star who relays some shiny new fact or explanation. These are the kinds of experiences you probably first think of when you think of learning. But we can also learn in another way: simply by thinking. Sometimes we can just set our minds to work—just let the ideas already in our heads tumble around and spark off each other—and, is if by magic, come away with a new understanding of the world. But how does this happen exactly? And does it only happen in humans? 

My guest today is Dr. Tania Lombrozo. Tania is a Professor of Psychology at Princeton University; she and her research group study learning, reasoning, explanation, belief, and more. In a recent paper, Tania outlines this puzzling alternative form of learning—learning by thinking, as it’s known—and presents evidence that it happens in both humans and AIs.

In this conversation, Tania and I talk about her longstanding work on explanation, and how it led her to study this less- obvious form of learning. We zoom in on four flavors of learning by thinking—learning through explanation, through simulation, through analogy, and through reasoning. We talk about the evidence that machines also learn in this way, and we consider whether animals could, too. We discuss how to resolve the paradox at the heart of "learning by thinking": how it could be that reshuffling old bits of knowledge can actually lead to new understanding. Along the way, Tania and I touch on: chain of thought prompting in LLMs, the Reddit community 'Explain Like I'm Five,’ the illusion of explanatory depth, the power of thought experiments, Darwin and Galileo, imagination and rationalization, how psychology and philosophy complement each other, and whether we can also learn—not just by thinking in our proverbial armchairs—but also by writing and talking.

So, happy 2025, friends! We've got some great stuff lined up for the coming year. If you like what we're doing with the show, we would—as ever—appreciate your support. And the main way you can support us is just by helping us get the word out—by telling a friend about us, or a colleague, or a student, or your thousands of social media followers.

Alright, without further ado, onto my conversation with Dr. Tania Lombrozo. Enjoy!

A transcript of this episode will be available soon.

Notes and links

3:30 – An influential early paper on “chain-of-thought prompting” in Large Language Models. A recent preprint by a team, including Dr. Lombrozo, exploring the cases where “chain-of-thought prompting” actually impairs performs in LLMs.

8:00 – For some of Dr. Lombrozo’s important earlier work on explanation, see here and here.

11:15 – The Reddit community ‘Explain Like I’m Five.’

13:00 – An early paper on the “curse of knowledge”—the difficulty of ignoring what you know.

19:00 – Dr. Lombrozo’s recent review article on “learning by thinking” is here. Another article of hers on the same topic is here.

20:00 – The original report of the “self-explanation” effect. The original report of the “illusion of explanatory depth.”

30:00 – For a basic description of Galileo’s falling bodies thought experiment see here. A discussion of this thought experiment by philosopher Tamar Gendler.

38:00 – For analysis of Darwin’s analogy between artificial and natural selection, see here and here.

42:00 – A paper on rationalization by Fiery Cushman. 

48:00 – A paper from Dr. Lombrozo’s lab on “need for explanation.” The original paper describing the construct of “need for cognition.”

52:00 – The original report of “framing effects” by Tversky and Kahneman.

54:00 – A paper by Annette Karmiloff-Smith discussing “representational redescription.”

1:02:00 – A recent overview of issues surrounding “explainable” AI. 

Recommendations

Alison Gopnik, Andrew Meltzoff, & Patricia Kuhl, The Scientist in the Crib

Frank Keil, Wonder: Childhood and the Lifelong Love of Science

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Happy holidays, friends! We will be back with a new episode in January 2025. In the meantime, enjoy this favorite from our archives!

-----

[originally aired Jun 14, 2023]

Have you heard of Octopolis? It’s a site off the coast of Australia where octopuses come together. It’s been described as a kind of underwater "settlement" or "city." Now, smart as octopuses are, they are not really known for being particularly sociable. But it seems that, given the right conditions, they can shift in that direction. So it's not a huge leap to wonder whether these kinds of cephalopod congregations could eventually give rise to something else—a culture, a language, maybe something like a civilization. 

This is the idea at the center of Ray Nayler's new book, The Mountain in the Sea. It's both a thriller of sorts and a novel of ideas; it’s set in the near future, in the Con Dao archipelago of Vietnam. It grapples with the nature of intelligence and meaning, with the challenges of interspecies communication and companionship, and ultimately with what it means to be human. 

Here, Ray and I talk about how he got interested in cephalopods and how he came to know the Con Dao archipelago. We discuss some of the choices he made as an author—choices about what drives the octopuses in his book to develop symbols and about what those symbols are like. We consider the major human characters in his book, in particular two ambitious researchers who embody very different approaches to understanding minds. We also talk a fair bit about AI—another central character in the book, after all, is a super-intelligent android. Along the way, Ray and I touch on Arrival, biosemiotics, the nature of symbols, memory and storytelling, embodiment, epigenetics, cephalopod camouflage, exaptation, and the sandbox that is speculative fiction. 

This episode is obviously something a little different for us. Ray is a novelist, after all, but he’s also an intellectual omnivore, and this conversation, maybe more than any other we’ve had on the show, spans three major branches of mind—human, animal, and machine. If you enjoy this episode, note that The Mountain in the Sea just came out in paperback, with a jaw-droppingly cool cover, I’ll add. I highly recommend that you check it out.

One more thing, while I have you: If you're enjoying Many Minds, we would be most grateful for your help in getting the word out. You might consider sharing the show with a friend or a colleague, writing us a review on Apple Podcasts, or leaving us a rating on Spotify or Apple. All this would really help us grow our audience. 

Alright friends, on to my conversation with Ray Nayler. Enjoy!

 A transcript of this episode is available here. 

Notes and links

8:30 – For the review of The Mountain in the Sea in question, see here. 

14:00 – Con Dao is a national park in Vietnam.

17:00 – For our previous episode about cephalopods, see here.

19:00 – For a book-length introduction to biosemiotics, see here.  

24:00 – A video of Japanese macaques washing sweet potatoes. 

26:30 – For discussion of the human case, in which environmental pressures of some kind may have propelled cooperation, see our episode with Michael Tomasello. 

29:00 – A popular article about RNA editing in cephalopods. 

35:00 – A video of the “passing cloud” phenomenon in cuttlefish. A brief article about the phenomenon. A video showing other forms of camouflage in octopuses.

41:00 – An experimental exploration of the movement from “iconic” to “symbolic” communication in humans. 

44:00 – A popular article about the communication system used in the movie Arrival. 

49:00 – One source of inspiration for Ray’s book was Eduardo Kohn’s How Forests Think. 

1:00:00 – An article on the idea of “architects” and “gardeners” among writers. 

1:05:00 – Ray’s story ‘The Disintegration Loops’ is available here.

1:11:00 – Ray’s story ‘The Summer Castle’ is available here. 

1:13:00 – A popular article about the phenomenon of highly superior autobiographical memory. An essay about the idea that faulty memory is a feature rather than a bug.

1:18:00 – Ray’s story ‘Muallim’ is available here.

Recommendations

Ways of Being, by James Bridle

Living in Data, by Jer Thorp

Follow Ray on Twitter.

Many Minds is a project of the Diverse Intelligences Summer Institute, 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 help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected].  

For updates about the show, visit our website or follow us on Twitter: @ManyMindsPod.

Using language is a complex business. Let's say you want to understand a sentence. You first need to parse a sequence of sounds—if the sentence is spoken—or images—if it's signed or written. You need to figure out the meanings of the individual words and then you need to put those meanings together to form a bigger whole. Of course, you also need to think about the larger context—the conversation, the person you're talking to, the kind of situation you're in. So how does the brain do all of this? Is there just one neural system that deals with language or several? Do different parts of the brain care about different aspects of language? And, more basically: What scientific tools and techniques should we be using to try to figure this all out?

My guest today is Dr. Ev Fedorenko. Ev is a cognitive neuroscientist at MIT, where she and her research group study how the brains supports language and complex thought. Ev and her colleagues recently wrote a detailed overview of their work on the language network—the specialized system in our brain that underlies our ability to use language. This network has some features you might have expected, and—as we’ll see—other features you probably didn't.

Here, Ev and I talk about the history of our effort to understand the neurobiology of language. We lay out the current understanding of the language network, and its relationship to the brain areas historically associated with language abilities—especially Broca's area and Wernicke's area. We talk about whether the language network can be partitioned according to the subfields of linguistics, such as syntax and semantics. We discuss the power and limitations of fMRI, and the advantages of the single-subject analyses that Ev and her lab primarily use. We consider how the language network interfaces with other major neural networks—for instance, the theory of mind network and the so-called default network. And we discuss what this all tells us about the longstanding controversial claim that language is primarily for thinking rather than communicating.

Along the way, Ev and I touch on: some especially interesting brains; plasticity and redundancy; the puzzle of lateralization; polyglots; aphasia; the localizer method; the decline of certain Chomskyan perspectives; the idea that brain networks are "natural kinds"; the heart of the language network; and the question of what the brain may tell us—if anything—about how language evolved.

Alright friends, this is a fun one. On to my conversation with Dr. Ev Fedorenko. Enjoy!

A transcript of this episode is available here. 

Notes and links

3:00 – The article by a New York Times reporter who is missing a portion of her temporal lobe. The website for the Interesting Brains project. 

5:30 – A recent paper from Dr. Fedorenko’s lab on the brains of three siblings, two of whom were missing portions of their brains. 

13:00 – Broca’s original 1861 report. 

18:00 – Many of Noam Chomsky’s ideas about the innateness of language and the centrality of syntax are covered in his book Language and Mind, among other publications.

19:30 – For an influential critique of the tradition of localizing functions in the brain, see William R. Uttal’s The New Phrenology.

23:00 – The new review paper by Dr. Fedorenko and colleagues on the language network. 

26:00 – For more discussion of the different formats or modalities of language, see our earlier episode with Dr. Neil Cohn.

30:00 – A classic paper by Herbert Simon on the “architecture of complexity.”

31:00 – For one example of a naturalistic, “task-free” study that reveals the brain’s language network, see here. 

33:30 – See the recent paper arguing “against cortical reorganization.”

33:00 – For more on the concept of “natural kind” in philosophy, see here. 

38:00 – On the “multiple-demand network,” see a recent study by Dr. Fedorenko and colleagues. 

41:00 – For a study from Dr. Fedorenko’s lab finding that syntax and semantics are distributed throughout the language network, see here. For an example of work in linguistics that does not make a tidy distinction between syntax and semantics, see here. 

53:30 – See Dr. Fedorenko’s recent article on the history of individual-subject analyses in neuroscience. 

1:01:00 – For an in-depth treatment of one localizer used in Dr. Fedorenko’s research, see here. 

1:03:30 – A paper by Dr. Stephen Wilson and colleagues, describing recovery of language ability following stroke as a function of the location of the lesion within the language network.

1:04:20 – A paper from Dr. Fedorenko’s lab on the small language networks of polyglots. 

1:09:00 – For more on the Visual Word Form Area (or VWFA), see here. For discussion of Exner’s Area, see here.  

1:14:30 – For a discussion of the brain’s so-called default network, see here. 

1:17:00 – See here for Dr. Fedorenko and colleagues’ recent paper on the function of language. For more on the question of what language is for, see our earlier episode with Dr. Nick Enfield. 

1:19:00 – A paper by Dr. Fedorenko and Dr. Rosemary Varley arguing for intact thinking ability in patients with aphasia. 

1:22:00 – A recent paper on individual differences in the experience of inner speech.

Recommendations

Dr. Ted Gibson’s book on syntax (forthcoming with MIT press)

Nancy Kanwisher, ‘Functional specificity in the human brain’

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

How do birds build their nests? By instinct, of course—at least that's what the conventional wisdom tells us. A swallow builds a swallow's nest; a robin builds a robin's nest. Every bird just follows the rigid template set down in its genes. But over the course of the last couple of decades, scientists have begun to take a closer look at nests—they've weighed and measured them, they've filmed the building process. And the conventional wisdom just doesn't hold up. These structures vary in all kinds of ways, even within a species. They're shaped by experience, by learning, by cultural tradition. When we look at a bird's nest, we're looking at the product of a flexible mind.

My guest today is Dr. Susan Healy. Sue is a Professor in the School of Biology at the University of St Andrews and an expert in birds—their behavior, their cognition, and their evolution. For more than a decade now, Sue has been pioneering a new chapter in the study of birds' nests. 

Here, Sue and I talk about some of the most impressive nests (as well as some of the least impressive). We do a bit of Birds' Nests 101—the different forms they take, the functions they serve, which sex does the building, how these structures evolved, and more. We dig into the mounting evidence that birds are in fact quite flexible in their building practices, that they learn from others and from their own experience. We discuss recent evidence from Sue's team that cultural traditions shape the weaver nests of the Kalahari. And we talk about what nests might have in common with songs and tools. Along the way, we touch on: pigeon nests and hummingbird nests, dinosaur nests and chimpanzee nests; Alfred Russel Wallace; commonalities in the techniques of human weavers and weaver birds; whether bird personality might be reflected in nest style; the brain basis of nest-building; and a whole lot else. 

Hope you enjoy this one, friends. On to my conversation with Dr. Sue Healy. 

A transcript of this episode is availalble here. 

Notes and links

2:30 – An example of a post on the (seemingly inadequate) nests of pigeons. 

7:30 – An article featuring a variety of weaverbird nests.

10:30 – Alfred Russel Wallace’s essay on birds' nests is available here. 

15:00 – A paper from another branch of Dr. Healy’s work, on hummingbirds. 

16:00 – The 1902 book by Charles Dixon on the science of “caliology.”

17:00 – An example of research done by the Colliases on weavers. 

19:00 – For an up-to-date primer on birds’ nests—covering a number of the questions we discuss here—see Dr. Healy’s recent primer.

22:30 – An article about hummingbird eggs. 

28:30 – A paper by Dr. Healy and colleagues on the use of human materials in birds’ nests. Our episode on animal medication is here. 

31:30 – An article about bowerbirds and how they decorate their bowers.

35:00 – An article on the evolution of birds’ nests, covering the question of what dinosaur nests were like. 

43:00 – A paper by Dr. Healy and colleagues on the impact of temperature and earlier breeding success on nest size.

51:00 ­– For more discussion of personality in animals, including in clonal fish, see our episode with Kate Laskowski. 

55:00 – A study by Dr. Healy and colleagues showing that zebra finches build nests that match the color of the walls. 

58:00 – A study by Dr. Healy and colleagues looking at how zebra finches learn aspects of nest-building from familiar individuals.

59:00 – A study by Dr. Healy and colleagues, led by Maria Tello-Ramos, about architectural traditions in an African sociable weaver species.  

1:07:00 – An article by Michael Arbib, Dr. Healy, and colleagues on connections between tool use, language, and nest-building. 

1:11:00 – An initial study on the brain basis of nest-building in zebra finches. A further study on the same topic. 

1:12:30 – A paper by Hopi E. Hoekstra and colleagues on the genetics of burrow-building in deer mice.  

1:14:00 – An exploration of the idea that humans initially learned their weaving skills from weaver birds.

Recommendations

Books by Mike Hansell (see here, here, and here)

Birds’ nests, Charles Dixon

Avian architecture, Peter Goodfellow

Animal architects, James Gould & Carol Gould

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. 

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Bluesky (@manymindspod.bsky.social).

What happens to animals when they get sick? If they’re pets or livestock, we probably call the vet. And the vet may give them drugs or perform a procedure. But what about wild animals? Do they just languish in misery? Well, not so much. It turns out that animals—from bees to butterflies, porcupines to primates—medicate themselves. They seek out bitter plants, they treat wounds, they amputate limbs, they eat clay—the list goes on. This all raises an obvious question: How do they know to do this? How do they know what they know about healing and medicine? It also invites a related question: How do we humans know what we know?

My guests today are Dr. Jaap De Roode and Dr. Michael Huffman. Jaap is a biologist at Emory University, and has studied animal medication in insects; he’s also the author of a forthcoming book about animal medication across the tree of life. Mike is a primatologist at the University of Nagasaki, and made some of the very first observations about animal self-medication in chimpanzees in the 1980s.

Here, Jaap, Mike, and I talk about how they found their way into this field, in both cases kind of by accident. We discuss what defines animal medication generally as well as what defines its more specific subtypes—social medication, allomedication, prophylactic medication, and others. We consider how animals know what they know about healing—whether these medicinal behaviors are mostly driven by innate tendencies, by individual experimentation, by social learning, or by some combination. We talk about the evidence that many of the medical insights that humans have had over the years actually began with observations of animals. Along the way, we touch on medicinal amputation and medicinal cannibalism, geophagy, leaf-folding in primates, animal quackery, bear medicine, why lemurs rub themselves with millipedes, and the anti-parasitic power of cigarette butts.

Alright, friends, this is a fun one. Enjoy!

A transcript of this episode is available here. 

Notes and links

3:00 – A paper describing how birds in Mexico City line their nests with cigarette butts. A follow-up experiment showing that they do so in response to increased presence of parasites.

7:30 – Dr. Huffman’s original study of self-medication by a chimpanzee, using Vernonia amygdalina in Tanzania.

15:00 – Dr. de Roode’s study on “transgenerational medicine” in monarch butterflies.

20:00 – For an overview of animal medication, including definitions and examples of its subtypes, see this recent primer by Dr. de Roode and Dr. Huffman.

25:00 – The recent study on “medicinal amputation” in ants. The recent study on “medicinal cannibalism” in ants.

30:00 –  For an overview of medication in insects, see this recent paper by Dr. de Roode and colleagues.

34:00 – The paper by Mascaro and colleagues showing that chimpanzees treat wounds (to the self and others) by applying insects.

38:00 – A recent review of geophagy—soil eating—in primates by Paula Pebsworth, Dr. Huffman, and colleagues.  

43:00 – A paper by Dr. Huffman and colleagues on chimpanzee leaf-swallowing in the wild. Dr. Huffman later did a series of experimental studies on this behavior, investigating the role of social learning—see here and here.

46:00 – An article on how goats learn to eat what they eat.      

52:00 – An article describing the medicinal properties of Vernonia amygdalina.

54:00 ­– A study showing that lemurs rub each other with millipedes in a possible case of animal medication.

57:00 – A paper by Dr. Huffman in which he describes the use of mulengelele by a sick porcupine. A recent review by Dr. Huffman of what traditional healers have learned from observations of animal medication.

1:01:00 – An article about propolis and its medicinal use in bees; an article about its medicinal potential in humans.  

Recommendations

Doctors by Nature, Jaap de Roode (forthcoming)

Wild Health, Cindy Engel

Nourishment, Fred Provenza

‘Five clever animals that treat and prevent their own illnesses,’ National Geographic

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

The machines are coming. Scratch that—they're already here: AIs that propose new combinations of ideas; chatbots that help us summarize texts or write code; algorithms that tell us who to friend or follow, what to watch or read. For a while the reach of intelligent machines may have seemed somewhat limited. But not anymore—or, at least, not for much longer. The presence of AI is growing, accelerating, and, for better or worse, human culture may never be the same. 

My guest today is Dr. Iyad Rahwan. Iyad directs the Center for Humans and Machines at the Max Planck Institute for Human Development in Berlin. Iyad is a bit hard to categorize. He's equal parts computer scientist and artist; one magazine profile described him as "the Anthropologist of AI." Labels aside, his work explores the emerging relationships between AI, human behavior, and society. In a recent paper, Iyad and colleagues introduced a framework for understanding what they call "machine culture." The framework offers a way of thinking about the different routes through which AI may transform—is transforming—human culture. 

Here, Iyad and I talk about his work as a painter and how he brings AI into the artistic process. We discuss whether AIs can make art by themselves and whether they may eventually develop good taste. We talk about how AIphaGoZero upended the world of Go and about how LLMs might be changing how we speak. We consider what AIs might do to cultural diversity. We discuss the field of cultural evolution and how it provides tools for thinking about this brave new age of machine culture. Finally, we discuss whether any spheres of human endeavor will remain untouched by AI influence. 

Before we get to it, a humble request: If you're enjoying the show—and it seems that many of you are—we would be ever grateful if you could let the world know. You might do this by leaving a rating or review on Apple Podcasts, or maybe a comment on Spotify. You might do this by giving us a shout-out on the social media platform of your choice. Or, if you prefer less algorithmically mediated avenues, you might do this just by telling a friend about us face-to-face. We're hoping to grow the show and the best way to do that is through listener endorsements and word-of-mouth. Thanks in advance, friends.

Alright, on to my conversation with Dr. Iyad Rahwan. Enjoy!

A transcript of this episode is available here.

Notes and links

3:00 – Images from Dr. Rahwan's ‘Faces of Machine’ portrait series. One of the portraits from the series serves as our tile art for this episode.

11:30 – The “stochastic parrots” term comes from an influential paper by Emily Bender and colleagues.

18:30 – A popular article about DALL-E and the “avocado armchair.”

21:30 – Ted Chiang’s essay, “Why A.I. isn’t going to make art.”

24:00 – An interview with Boris Eldagsen, who won the Sony World Photography Awards in March 2023 with an image that was later revealed to be AI-generated. 

28:30 – A description of the concept of “science fiction science.”

29:00 – Though widely attributed to different sources, Isaac Asimov appears to have developed the idea that good science fiction predicts not the automobile, but the traffic jam. 

30:00 – The academic paper describing the Moral Machine experiment. You can judge the scenarios for yourself (or design your own scenarios) here.

30:30 – An article about the Nightmare Machine project; an article about the Deep Empathy project.

37:30 – An article by Cesar Hidalgo and colleagues about the relationship between television/radio and global celebrity.

41:30 – An article by Melanie Mitchell (former guest!) on AI and analogy. A popular piece about that work.  

42:00 – A popular article describing the study of whether AIs can generate original research ideas. The preprint is here.

46:30 – For more on AlphaGo (and its successors, AlphaGo Zero and AlphaZero), see here.

48:30 – The study finding that the novelty of human Go playing increased due to the influence of AlphaGo.

51:00 – A blogpost delving into the idea that ChatGPT overuses certain words, including “delve.” A recent preprint by Dr. Rahwan and colleagues, presenting evidence that “delve” (and other words overused by ChatGPT) are now being used more in human spoken communication. 

55:00 – A paper using simulations to show how LLMs can “collapse” when trained on data that they themselves generated. 

1:01:30 – A review of the literature on filter bubbles, echo chambers, and polarization.

1:02:00 – An influential study by Dr. Chris Bail and colleagues suggesting that exposure to opposing views might actually increase polarization. 

1:04:30 – A book by Geoffrey Hodgson and Thorbjørn Knudsen, who are often credited with developing the idea of “generalized Darwinism” in the social sciences. 

1:12:00 – An article about Google’s NotebookLM podcast-like audio summaries.

1:17:3 0 – An essay by Ursula LeGuin on children’s literature and the Jungian “shadow.”

Recommendations

The Secret of Our Success, Joseph Henrich

“Machine Behaviour,” Iyad Rahwan et al.

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

IQ is, to say the least, a fraught concept. Psychologists have studied IQ—or g for “general cognitive ability”—maybe more than any other psychological construct. And they’ve learned some interesting things about it. That it's remarkably stable over the lifespan. That it really is general: people who ace one test of intellectual ability tend to ace others. And that IQs have risen markedly over the last century. At the same time, IQ seems to be met with increasing squeamishness, if not outright disdain, in many circles. It's often seen as crude, misguided, reductive—maybe a whole lot worse. There's no question, after all, that IQ has been misused—that it still gets misused—for all kinds of racist, classist, colonialist purposes. As if this wasn't all thorny enough, the study of IQ is also intimately bound up with the study of genetics. It's right there in the roiling center of debates about how genes and environment make us who we are. So, yeah, what to make of all this? How should we be thinking about IQ?

My guest today is Dr. Eric Turkheimer. Eric is Professor of Psychology at the University of Virginia. He has studied intelligence and many other complex human traits for decades, and he's a major figure in the field of “behavior genetics.” Eric also has a new book out this fall—which I highly recommend—titled Understanding the Nature-Nurture Debate. In a field that has sometimes been accused of rampant optimism, Eric is—as you'll hear—a bit more measured.

In this conversation, Eric and I focus on intelligence and its putatively genetic basis. We talk about why Eric doubts that we are anywhere close to an account of the biology of IQ. We discuss what makes intelligence such a formidable construct in psychology and why essentialist understandings of it are so intuitive. We talk about Francis Galton and the long shadow he’s cast on the study of human behavior. We discuss the classic era of Twin Studies—an era in which researchers started to derive quantitative estimates of the heritability of complex traits. We talk about how the main takeaway from that era was that genes are quite important indeed, and about how more recent genetic techniques suggest that takeaway may have been a bit simplistic. Along the way, Eric and I touch on spelling ability, child prodigies, the chemical composition of money, the shared quirks of twins reared apart, the Flynn Effect, the Reverse Flynn Effect, birth order, the genetics of height, the problem of missing heritability, whether we should still be using IQ scores, and the role of behavior genetics in the broader social sciences. 

Alright folks, lots in here—let's just get to it. On to my conversation with Dr. Eric Turkheimer. Enjoy!

A transcript of this episode is available here.

Notes and links

3:30 – The 1994 book The Bell Curve, by Richard Herrnstein a Charles Murray, dealt largely with the putative social implications of IQ research. It was extremely controversial and widely discussed. For an overview of the book and controversy, see the Wikipedia article here.

6:00 – For discussion of the “all parents are environmentalists…” quip, see here.

12:00 – The notion of “multiple intelligences” was popularized by the psychologist Howard Gardner—see here for an overview. See here for an attempt to test the claims of the “multiple intelligences” framework using some of the methods of traditional IQ research. For work on EQ (or Emotional Intelligence) see here.

19:00 – Dr. Turkheimer has also laid out his spelling test analogy in a Substack post.

22:30 – Dr. Turkheimer’s 1998 paper, “Heritability and Biological Explanation.”

24:30 – For an in-passing treatment of the processing efficiency idea, see p. 195 of Daniel Nettle’s book Personality. See also Richard Haier’s book, The Neuroscience of Intelligence.

26:00 – The original study on the relationship between pupil size and intelligence. A more recent study that fails to replicate those findings.

31:00 – For an argument that child prodigies constitute an argument for “nature,” see here. For a memorable narrative account of one child prodigy, see here.

32:00 – A meta-analysis of the Flynn effect. We have previously discussed the Flynn Effect in an episode with Michael Muthukrishna.

37:00 – James Flynn’s book, What is Intelligence? On the reversal of the Flynn Effect, see here.

40:00 – The phrase “nature-nurture” originally comes from Shakespeare and was picked up by Francis Galton. In The Tempest, Prospero describes Caliban as “a born devil on whose nature/ Nurture can never stick.”

41:00 – For a biography of Galton, see here. For an article-length account of Galton’s role in the birth of eugenics, see here.

50:00 – For an account of R.A. Fisher’s 1918 paper and its continuing influence, see here.

55:00 – See Dr. Turkheimer’s paper on the “nonshared environment”—E in the ACE model.

57:00 – A study coming out of the Minnesota Study of Twins reared apart. A New York Times article recounting some of the interesting anecdata in the Minnesota Study.

1:00:00 – See Dr. Turkheimer’s 2000 paper on the “three laws of behavior genetics.” Note that this is not, in fact, Dr. Turkheimer’s most cited paper (though it is very well cited).

1:03:00 – For another view of the state of behavior genetics in the postgenomic era, see here.

1:11:00 – For Dr. Turkheimer’s work on poverty, heritability, and IQ, see here.

1:13:00 – A recent large-scale analysis of birth order effects on personality.

1:16:00 – For Dr. Turkheimer’s take on the missing heritability problem, see here and here.   

1:19:00 – A recent study on the missing heritability problem in the case of height.

1:30:00 – On the dark side of IQ, see Chapter 9 of Dr. Turkheimer’s book. See also Radiolab’s series on g.

1:31:00 – See Dr. Turkheimer’s Substack, The Gloomy Prospect.

Recommendations

The Genetic Lottery, Kathryn Paige Harden

Intelligence, Stuart Ritchie

Intelligence and How to Get It, Richard Nisbett

‘Why our IQ levels are higher than our grandparents’’ (Ted talk), James Flynn

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected].

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Forests have always been magical places. But in the last couple decades, they seem to have gotten a little more magical. We've learned that trees are connected to each other through a vast underground network—an internet of roots and fungi often called the "wood wide web". We've learned that, through this network, trees share resources with each other. And we've learned that so-called mother trees look out for their own offspring, preferentially sharing resources with them. There's no question that this is all utterly fascinating. But what if it's also partly a fantasy?

My guest today is Dr. Justine Karst. Justine is a forest ecologist at the University of Alberta. Her research focuses on mycorrhizas—these are the symbioses formed between fungi and plant roots that are thought to be the basis of the "wood wide web." Last year, Justine and colleagues published a perspective piece in which they argued that some of the claims around the wood wide web have gotten out of hand. These new ideas about forests, they argued, have gotten decoupled from the actual on-the-ground—or under-the-ground—science. In reality, it’s a field still riddled with unknowns and mixed findings.

Here, Justine and I do a bit of mycorrhiza 101—we talk about what mycorrhizas are, how they evolved, and what the structures actually look like. We discuss the original 1997 study that inspired the term "wood wide web." We consider why it's so hard to figure out what's actually going on, mechanistically, under the forest floor. We discuss the increasingly popular notion of plant intelligence and what it means to empirical researchers in this area like Justine. We talk about why people—both members of the public and scientists themselves—have found wood wide web ideas so charming. And, finally, we discuss the question of whether a little bit of hype is really so bad—particularly if it gets people excited about forests, about science, and about conservation.

I got as excited about the "wood wide web" as anyone. The idea totally captured my imagination a couple of years ago. So I was intrigued—if also a little dismayed—to learn recently that these ideas were getting some pushback. And I knew immediately we should talk to one of the researchers leading that pushback.

Alright friends, let's get to it. On to my conversation with Dr. Justine Karst. Enjoy!

A transcript of this episode is available here.

Notes and links

5:00 – Popular treatments sometimes mentioned as over-hyping the wood wide web (and associated ideas) include The Hidden Life of Trees, Finding the Mother Tree, and the novel The Overstory.

9:30 – The landmark 1997 paper by Simard et al. that kicked off interest in the so-called wood wide web.

11:00 – A study showing that fungi are more closely related to animals than to plants.

11:30 – For more on the new interest in “plant intelligence” see our previous episodes here and here. On the notion of “fungal intelligence,” see here.

18:00 – A 1975 paper presenting a hypothesis about the origins of land plants.

20:00 – The California “mushroom bible” mentioned.

23:00 – A brief post (and infographic) on the differences between arbuscular mycorrhizas and ectomycorrhizas.

23:30 – Richard Powers’ influential novel, The Overstory. Note that the novel doesn’t exclusively focus on the wood wide web; it covers ideas and findings about trees and forests, many of which are uncontroversial.

36:00 – Dr. Karst co-authored her perspective piece in Nature Ecology & Evolution with Dr. Melanie Jones and Dr. Jason Hoeksema.

50:00 – For more on aspens and how they constitute clonal organisms, see here.

52:00 – The “mother tree” idea was popularized in Dr. Suzanne Simard’s book, Finding the Mother Tree.

1:04:00 – Another recent critique of the wood wide web and mother tree idea is here. In it the authors write: “Reaching out to the general public to make people care about forests is certainly a praiseworthy goal, but not when it involves the dissemination of a distorted view of the plant world. In other words: the end does not justify the means.”

1:05:30 – Others influenced by The Overstory include Barack Obama and Bill Gates.

1:09:00 – A primer on myco-heterotrophic plants.

1:13:00 – See a recent presentation by Dr. Jared Farmer on trees and “chronodiversity” here.

Recommendations

‘Seeing plants anew,’ Stella Stanford

‘Mother trees and socialist forests: Is the ‘wood-wide web’ a fantasy?’, Daniel Immerwahr

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

There's a bit of a buzz out there, right now, but maybe you haven’t noticed. It's in the water, it's in the air. It's electricity—and it's all around us, all the time, including in some places you might not have expected to find it. We humans, after all, are not super tuned in to this layer of reality. But many other creatures are—and scientists are starting to take note.

My guest today is Dr. Sam England. Sam is a sensory ecologist at the Natural History Museum in Berlin, and one of a handful of scientists uncovering some shocking things about the role of electricity in the natural world.

Here, Sam and I have a wide-ranging conversation about electroreception—which is the perception of electrical stimuli—and electric ecology—which is the study of the ecological roles of electricity. We talk about how an interest in electroreception first got started, and why it's recently resurged. We discuss aquatic electroreception versus aerial electroreception, active electroreception versus passive electroreception. We talk about how electroreception is actually kind of easy to evolve. Along the way, we consider electrolocation and, its analog in sound, echolocation. We touch on dolphins, sharks, echidnas, ticks, caterpillars, bees, and spiders. We zoom in on electrostatic pollination, and what is inarguably the coolest sounding anatomical structure known to biology: the ampullae of Lorenzini.

I think you'll enjoy this one, friends. As Sam describes here, electroreception is one of those "alien senses"—it really challenges the imagination. And electric ecology is one of those frontiers in our understanding of the natural world. So without further ado, here's my chat with Dr. Sam England. Enjoy!

A transcript of this episode is available here.

Notes and links

3:00 – For many of the topics discussed in this episode, see this comprehensive recent review of electroreception and electric ecology by Dr. England and a colleague.

7:30 – A paper reviewing the (contested) phenomenon of electromagnetic hypersensitivity in humans.

9:30 – An encyclopedia article on electroreception in monotremes.

13:00 – An early study of electrolocation in “weakly electric” fish.

17:00 – A popular article about the discovery of electroreception in sharks.

20:30 – A 2013 study showing that bumblebees detect the electric fields around flowers.

23:30 – A recent review of electroreception and its evolution in fish.  

25:00 – A study demonstrating electroreception in the Guiana dolphin.

34:00 – A recent study by Dr. England and colleagues showing that static electricity pulls ticks onto hosts.

43:00 – For more on echolocation, see our earlier episode on bats.

47:00 – A recent paper by Dr. Ryan Palmer, examining the theoretical possibilities of electroreception in air.

52:30 – A (controversial) 2022 paper on possibly language-like communication in fungi via electricity.

55:00 – Another 2013 study on electroreception in bees, this one in honeybees.

56:30 – An animated video describing the role that electricity plays in spider ballooning.

1:00:00 – Dr. England’s recent study showing that caterpillars can detect the electric fields around wasps.

1:03:00 – A discussion of triboelectric effects.

1:11:00 – Dr. England’s recent study of electrostatic pollination in butterflies and moths.

1:19:00 – A study arguing that the sexual organs of flowers may have evolved to take advantage of electrostatic pollination.

1:25:00 ­– For more on spider eyes, see our recent episode all about spiders.

Recommendations

‘Electroreception, electrogenesis and electric signal evolution,’ William Crampton

An Immense World, Ed Yong (a previous guest!)

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

The idea of a "maternal instinct"—the notion that mothers are wired for nurturing and care—is a familiar one in our culture. And it has a flipside, a corollary—what you might call “paternal aloofness.” It's the idea that men just aren't meant to care for babies, that we have more, you know, manly things to do. But when you actually look at the biology of caretaking, the truth is more complicated and much more interesting.

My guest today is Dr. Sarah Blaffer Hrdy. She is Professor Emerita of Anthropology at the University of California, Davis and the author of the new book,  Father Time: A Natural History of Men and Babies. In it, she examines paternal care, the biology that supports it, and the norms and practices that sometimes suppress it.

In this conversation, Sarah and I set her new book, Father Time, in the context of her four previous books. We discuss the surprising prevalence of male care in fish and amphibians. We talk about how Charles Darwin noted the plasticity of caretaking in animals, only to ignore that plasticity when talking about humans. We consider how time in intimate proximity with babies activates capacities for nurturing—not just in fathers, but in caretakers of all kinds. Along the way, we touch on langurs and owl monkeys; emus and cassowaries; cichlid fish and fairy shrimp; prolactin and oxytocin; patriarchy and patriarchal notions. We talk about what seems to be distinctive about the human capacity for care; and about what happens when males spend too much time competing for status, and not enough time snuggling babies.

You'll probably get a sense for this from our conversation, but there are very few researchers who take both biology and culture as seriously as Sarah Blaffer Hrdy does. She does not shy away from digging deep into either domain. And she does not shy away from trying to trace the tangled links between the two.

Alright friends, I hope you enjoy this one. On to my conversation with Dr. Sarah Blaffer Hrdy.

A transcript of this episode is available here.

Notes and links

3:00 – A classic paper on male parental care in fishes.  

7:00 – Dr. Hrdy’s previous books include The Langurs of Abu, The Woman that Never Evolved, Mother Nature, and Mothers and Others.

13:00 – A academic article  on “cooperative breeding” in birds.

16:30 – The full text of Charles Darwin’s book, The Descent of Man.

21:00 – Read about Caroline Kennard and her correspondence with Darwin here.

23:30 – A review of a recent book on Nancy Hopkins and her (quantitative) efforts to expose sexism at MIT.

26:00 – The 2014 paper on the brains of fathers in different caretaking roles.

37:00 – A paper by Larry Young and a colleague on the role of ancient peptides (like oxytocin) in sociality.

40:00 – The lab of Dr. Lauren O’Connell, who studies physiology and social behavior in poison dart frogs.

42:00 – A review of paternal care in primates.

47:00 – For more on Michael Tomasello’s “mutualism hypothesis”—and a lot else—see our earlier episode with Dr. Tomasello.

49:00 – For more on the costliness of the human brain, see our earlier episodes here and here.

58:00 – The 2007 study by Esther Herrmann, Michael Tomasello, and colleagues on the human specialization for social cognition.

59:00 – A study of children’s early “ostensive gestures” of showing and offering.

1:02:00 – An obituary for the ethnographer Lorna Marshall.

1:09:00 – An overview of ostracods and the traces they leave in the fossil record.

Recommendations

The Parental Brain, Michael Numan

Silas Marner, George Eliot

Endless Forms Most Beautiful, Sean Carroll

Your Inner Fish, Neil Shubin

Brave Genius, Sean Carroll

Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.

Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here!

We welcome your comments, questions, and suggestions. Feel free to email us at: [email protected]. 

For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).