Many Minds

Matt Longo, cognitive neuroscience professor and author of The Invisible Hand, studies how the brain represents the hand. He contrasts the visible anatomy with the brain's invisible maps. Short, lively conversations span evolution, fingertip sensitivity and cortical magnification, odd cases like extra digits and rubber-hand illusions, and how tools and tech reshape our manual lives.

Hi friends! We're skipping a beat to take care of some spring housekeeping tasks. We will be back in May! In the meanwhile, enjoy this listener favorite from our archives! ----- [originally aired April 30, 2025] We humans have a hard time becoming invisible. For better or worse, we're basically stuck with the skin and body we have; we're pretty fixed in our color, our shape, our overall appearance. And so we're fascinated by creatures that aren't—creatures that morph to meet the moment, that can functionally disappear, that can shape-shift on a dime. And no creatures are more skilled, more astonishing, more bedazzling in their abilities to do this kind of thing than the cephalopods. But how do they do this exactly? What's going on in their skin? What's going on under their skin? And what's going on in their brains that makes this all possible? My guest today is Dr. Tessa Montague. Tessa is a neuroscientist in the Axel Lab at Columbia University; she studies the brain and behavior of the dwarf cuttlefish, with a special focus on the biology of their dynamic skin behaviors. Here, Tessa and I talk about how cuttlefish and other cephalopods exhibit the most impressive camouflaging abilities on the planet. We discuss how they change their skin's appearance with remarkable speed and fidelity—and not just when trying to blend in, but also when hunting, courting, fighting, and more. We talk about whether these behaviors are flexible and whether they're voluntary. We linger on the cruel irony that cuttlefish seem to be colorblind. We talk about the idea that a cephalopod's skin is kind of a window into their brain. We lay out the cells and organs in the cephalopod skin the make these behaviors possible—especially the tiny pigment-bearing structures called "chromatophores." And of course we also dive deep into the cephalopod brain and its sometimes bizarre and poorly understood structures. Excited to share it with you friends—I think you'll enjoy it. Without further ado, here's my chat with Dr. Tessa Montague. A transcript of this episode is available here. Notes and links 3:00 – For more on Dr. Montague's recent expeditions to the Philippines, including photos, see here. 7:30 – Dr. Montague has published two recent reviews of dynamic skin behaviors in cephalopods—see here and here. We previously discussed cephalopod intelligence in a 2021 episode with Dr. Alex Schnell and a 2023 episode with the novelist Ray Nayler. 18:30 – For discussion of a recent "renaissance" in new model organisms, see here. 20:30 – For more on how chameleons change color, see this video. 25:00 – A video primer on cuttlefish camouflage, featuring the researcher Dr. Robert Hanlon. 30:30 – A recent paper on the details of pattern matching in cuttlefish camouflage. 31:00 – For more on the mimicking plant Boquila trifoliolata, see this popular article. See also our earlier episode with Dr. Paco Calvo and Dr. Natalie Lawrence. 35:00 – A video about the so-called mimic octopus. 40:00 – For the hypothesis about color discrimination via chromatic aberration and pupil shape, see here. 44:00 – For more on the "split body" skin behaviors observed in some cuttlefish, see here. 51:00 – For the David Attenborough clip about a cuttlefish hypnotizing a crab, see here. For the recent New York Times article on cuttlefish hunting behavior, including videos, see here. For the academic article that inspired the New York Times piece, see here. 58:00 – A recent scientific study on the possibility of octopus skin activity during dreaming. A video that helped popularize the idea of cephalopod skin activity as evidence of dreaming. Our earlier episode on why we—and other creatures—dream. 1:06:00 – For a study on chromatophore development from the lab of Dr. Gilles Laurent, see here. 1:11:00 – For more on papillae, including videos, see here. 1:17:00 – To explore an animated model of the cuttlefish brain, see this page of Dr. Montague's website, Cuttlebase. Recommendations Monarchs of the Sea, Danna Staaf Other Minds, Peter Godfrey-Smith Cephalopod Behavior, Roger Hanlon & John B. Messenger 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: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Deep in our past, in the dark depths of caves, our ancestors did something strange and beautiful. Working by firelight, some doodled little designs. Others made hand stencils. Some saw a bulge of rock, or a crack in the wall, and thought to turn it into a horse or a bison. Why did they make this art? What did it mean to them? Who were these artists? These questions are old—very old—but thanks to new methods and new interpretive frameworks, archaeologists are beginning to see them in a new light. My guest today is Dr. Izzy Wisher. Izzy is an archaeologist at Aarhus University in Denmark, specializing in Paleolithic art. Here, Izzy and I talk about why we in the present are so drawn to cave art. We lay out the basic timeline, geography, and categories of Paleolithic art. We consider the difference between figurative and non-figurative art, and why it might be that non-figurative art came first. We discuss hand stencils. We talk about an ongoing shift in archaeology known as the "sensory turn." We dig into some of Izzy's work on the role of pareidolia, palimpsests, and children in cave art. And we touch on an ongoing project she is involved in trying to understand the earliest symbolic marks that our species made—and what they could have been used for. Along the way we touch on the site known as El Castillo, Werner Herzog, hunting magic, why hand stencils are so often missing fingers, graffiti, tectiforms and flutings, why depictions of humans are actually quite rare in cave art, stages in children's art production, the use of virtual reality as a research method, and the idea of archaeology as world-building. I think you'll enjoy this one friends. Who among us—after all—doesn't feel drawn to these caves, to these most enigmatic of human creations? Without further ado, here's my conversation with Dr. Izzy Wisher. Notes 3:00 – For more on El Castillo cave, see here and here. 9:00 – Werner Herzog's film—Cave of Forgotten Dreams—is being briefly re-released in April 2026. 12:00 – For some of Dr. Wisher's popular writing on cave art, see here and here. 16:30 – One example of a recent rock art finding in Sulawesi. 20:30 – Our earlier episode with Dr. Eleanor Scerri and Dr. Manuel Will, in which we discuss the mostly retired idea of a "cognitive revolution" in Europe in the Upper Paleolithic. 22:00 – For more on the recently discovered rock art panel in Colombia, see this news story and this recent academic study. 25:00 – The relative rarity of humans in Paleolithic art has provoked much discussion, both among scholars and the public. 27:00 – On the idea that Venus figurines might be self-representations—made from the perspective of the artist viewing her own body—see here. 29:00 – For a recent treatment of the "missing fingers" in hand stencils, with some overview of different hypotheses, see here. For more on the idea that such stencils could constitute a system of hand-signs, see here. 34:00 – A popular article by Dr. Wisher about one example of portable art—a deer-tooth necklace with engraved designs. 36:00 ­– For a discussion of the earliest non-figurative art, see here. For one account of the transition from non-figurative to figurative art, including discussion of hand stencils, see here. 42:00 – A paper in which Dr. Wisher and a colleague discuss the "sensory turn" in archaeology and how her work contributes to it. 51:00 – Dr. Wisher's studies on pareidolia are here and here. 59:00 – For Dr. Wisher's study of palimpsests in cave art, see here. 1:07:00 – For an influential early study on cave marking by children, see here. For Dr. Wisher's recent study of children's art in the caves, see here. A book by Dr. John Matthews on the development of drawing in children. 1:14:00 – The website of the eSYMB project is here. An important early publication by this group is here. A recent overview of the project and its context by Dr. Wisher and colleagues. 1:18:00 – A recent paper arguing that certain systems of marks represented a "phenological calendar." Another recent paper providing evidence that certain Paleolithic marks constituted a system of conventional signs. 1:22:00 – The paper arguing that archaeology is "world-building." Recommendations Kindred, by Rebecca Wragg Sykes (former guest!) Homo sapiens rediscovered, by Paul Pettitt 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. 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: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Bluesky (@manymindspod.bsky.social).

Gary Lupyan, a UW–Madison psychologist who studies language and cognition, and Mike Frank, a Stanford psychologist focused on language learning in children, explore what modern AI reveals about the mind. They compare LLMs to child learning, debate data gaps and grounding, examine language as a potent training signal, and probe model reasoning, confabulations, and the limits of pattern matching.

Rob Dunn, Professor of Applied Ecology who studies the creatures around us, joins to explore interspecies mutualisms. He discusses fermentation and how yeasts shaped human history. He tells stories of honeyguides, dolphin-human fishing, dogs as sensory partners, and the curious roles of cats, maggots, cheese microbes, and body microbes. The conversation invites thinking about a less lonely, more biodiverse future.

Melanie Mitchell, computer scientist and Santa Fe Institute professor who wrote AI: A Guide for Thinking Humans, joins to unpack seven vivid metaphors for AI. They compare AI to crowds, role-players, alien intelligences, cultural technologies, and more. Short scenes explore anthropomorphism, evaluation pitfalls, analogy-making by models, and how these metaphors shape law, policy, and how we relate to AI.

Matilda Brindle, an evolutionary biologist at Oxford who studies the origins of animal behavior, explores why humans kiss. She traces kissing across primates, considers functions like mate assessment, microbiome sharing and pre‑mastication roots. The conversation highlights deep evolutionary roots, cultural variation, and surprising methods used to study this intimate, risky behavior.

Metaphors matter. They enliven our speech and our prose; they animate our arguments and stir our passions. Some metaphors power political movements; others propel scientific revolutions. These little figures of speech delight, provoke, captivate, shock, amuse, and galvanize us. In one way or another, metaphors just seem to help us make sense of a messy world. But how do they do all this? Whence their peculiar powers? What does it say about the human mind that we just can't escape our metaphors—and frankly don't want to? My guest today is Dr. Stephen Flusberg. Steve is an Assistant Professor of Cognitive Science at Vassar College, where he directs the Framing, Reasoning, And Metaphor (FRAME) Lab. Here, Steve and I talk about what metaphors are and why we're so drawn to them. We discuss some of the misleading ideas about metaphor you may remember from middle school literature class. We consider why some metaphors work and others flop. We talk about the metaphors we use for climate change and prevalence and potency of war metaphors across different realms of public discourse. We consider how metaphor operates in science and in scientific theorizing. Finally, we talk about the question of whether there are some ideas that we simply can't grasp literally, concepts we can only approach through metaphor. Along the way, Steve and I talk about: "aura farming"; nautical metaphors and textile metaphors; the outmoded idea that metaphors are mere adornments; metaphor versus analogy; dead metaphors and how to resuscitate them; shadows and footprints; Dan Dennett's technique of metaphorical triangulation; and the brain-as-computer metaphor—and whether it is actually a metaphor. Alright, friends this is a fun one. Steve has spent his entire career exploring this fascinating terrain—and, as you'll see, he's a lively and affable guide. Hope you enjoy it as much as I did. Without further ado, here's my conversation with Dr. Steve Flusberg. Notes 3:00 – For more on "beige flags," see here. For more on "aura farming," see here. 8:00 – For an overview of metaphor in communication and thought, see here for an article by Dr. Flusberg and co-authors. 18:00 – The "life is a journey" (or "career is a journey") metaphor—as well as other examples we discuss—are treated at length in the classic book, Metaphors We Live By. 24:00 – For a detailed academic treatment of the relationship between metaphor and analogy, see here. 32:00 – Some of the best-studied "orientational metaphors" are those found in the domain of time. See here and here. 37:00 – For more on metaphors used in discussions of environmental issues, see a paper by Dr. Flusberg and a colleague here. 42:00 – For more on the idea of the "climate shadow," see here. 46:00 – The study by Dr. Flusberg and colleagues comparing the effects of race and war metaphors for climate change. 55:00 – The article by Dr. Flusberg and colleagues on the role of war metaphors across different areas of public discourse. 1:04:00 – For an influential discussion of the role of metaphors and analogies in science, see here. For Kensy's take on Darwin's metaphors for natural selection, see here. For discussion of whether the "brain-as-computer" metaphor is actually a metaphor, see here and here. 1:12:00 – For more on the history of metaphors in the English language—including analyses of which source domains have historically been the most fruitful—see here. 1:14:00 – For discussion of the (disputed) idea of "dead metaphors," see here and here. 1:17:00 – The idea of "theory-constitutive metaphors" in science is discussed in a chapter by Richard Boyd in this book. 1:19:00 – For a preview of Dr. Flusberg's in-progress paper on the philosopher Daniel Dennett and his technique of "metaphorical triangulation," see here. 1:33:00 – For the (extremely short) Borges' story on maps that are too accurate to be useful, see here. Recommendations Metaphors We Live By, by George Lakoff & Mark Johnson Consciousness Explained, by Daniel Dennett Three Sheets to the Wind, by Cynthia Barrett 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. 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: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Bluesky (@manymindspod.bsky.social).

Hello friends, and happy new year! We're gearing up for a new run of episodes starting later in January. In the meanwhile, enjoy this pick from our archives. ------ [originally aired October 16, 2024] 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: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Matthew Cobb, a biologist and historian of science renowned for his work on neuroscience, dives deep into the complexities of the human brain. He discusses the historical shift from viewing the heart as the center of thought to recognizing the brain's role. Cobb illuminates the evolution of ideas like phrenology and localization of function, alongside the modern challenges of understanding consciousness. He critiques the limitations of psychiatric drugs and the ambitious yet flawed Human Brain Project, all while exploring how consciousness may emerge from neural interactions.