Many Minds

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.

Alright, friends—we've come to the end of the 2025 run of Many Minds! Our final episode of the year is an audio essay by yours truly. This is a classic format for the show, one that we only do every so often. Today's essay is about names. It's about the question of whether animals have something like names for each other. And it's also about a deeper question: What even is a name? How do humans use names? How does the historical and ethnographic record kind of complicate our everyday understanding of what names are. I had a lot of fun putting this together, and I do hope you enjoy it. Now, the holiday season is a time when people might be shopping around for new podcasts to listen to. That makes it a great time to recommend us to your friends and family and colleagues. You can think of it as an especially thoughtful gift, one that's absolutely free, and that keeps on giving throughout the year. Speaking of gifts, as an addendum to this episode you'll find a little stocking stuffer after the credits. It's a reading of a poem that figures prominently in today's essay. Without further ado, here is my essay—'In search of names.' Enjoy! A text version of this essay will be published shortly. Notes 2:00 – The text of 'The Naming of Cats' by T.S. Eliot is here. See also the full collection, Old Possum's Book of Practical Cats. The lines about cats' taste preferences and cats having different kinds of minds comes from another poem in the collection, 'The Ad-Dressing of Cats.' 3:00 – The 2019 study finding that cats know their names, and the 2022 study showing that cats know the names of their friends. 4:00 – For an overview of research on dolphin "signature whistles," see here. 5:00 – For the 2024 study reporting name-like rumbles in elephants, see here. 6:00 – For the 2024 study reporting vocal labels for individuals in marmosets, see here. A critical response to the study is here; the authors' response to the criticism is here. 12:00 – For overviews of cross-cultural variation in names and naming practices, see here, here, here, and here. Richard Alford's 1988 study, published in book form, is here. 13:30 – The study reporting name signs in Kata Kolok is here. 15:00 – For research on expectations based on the sounds of people's names, see here and here. 16:00 – For recent work on the "face-name matching effect," see here. For the study on "nominative determinism" in the medical profession, see here. (Note that, while this latter study does report empirical data, its rigor is questionable. And, yet, at least one other study has reported similar findings.) 17:30 – For the example of over-used names in Scotland, see here. 19:30 – For discussion of names in New Guinea, see here. For examples of research on "teknonymy," see here and here. For discussion of Penan "necronyms," see here. 20:30 – For an overview of name taboos, see here. For more on "alexinomia," see here. 22:30 – For an example of recent work on "name uniqueness," see here. 23:00 – William Safire's column on dog names is here. The study of gravestones in the world's oldest pet cemetery is here. 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).

Dr. Philippa Brakes, a behavioral ecologist and conservation scientist, delves into the vibrant world of animal cultures, challenging the notion that culture is uniquely human. She explores how social learning facilitates cultural transmission among species, from birds' songs to chimpanzee tool use. The discussion reveals the profound implications for conservation, emphasizing that recognizing animal cultures has intrinsic value beyond mere utility. Philippa also highlights innovative ideas like 'cultural rescue' to aid endangered species, making a compelling case for a new approach in wildlife management.

In this discussion, Dr. Ali Boyle, a philosopher at the London School of Economics, and Dr. Johannes Mahr, a researcher at York University in Toronto, dive deep into the mysteries of memory. They explore the intriguing relationship between episodic and semantic memory, proposing that episodic memory aids communication and enriches our semantic knowledge. They also discuss why certain memories linger and the implications for children and animals. Expect insight into how memory shapes our experiences and understanding of the world.

Dr. Erin Hecht, an Assistant Professor at Harvard and director of the Canine Brains Project, delves into the fascinating evolution of dog brains. She explains how domestic dogs have adapted anatomically through various domestication waves. Discussing breed-specific brain structures linked to functions like scent hunting and social interaction reveals the complexity of canine cognition. Erin also shares insights on dogs’ shared language pathways with humans and the implications of contemporary breeding practices on dog health and behavior.

It seems we've always had monsters among us. We've long been enthralled by dragons and giants, by the likes of Frankenstein and Godzilla and Dracula, by witches and werewolves and countless others. They roam our maps and creation myths; they crop up in our dreams, in our children's books, in our political rhetoric. Where do these beings spring from? What do they do for us? How have they changed over time? And, ultimately, what do our monsters say about their makers? My guests today are Dr. Natalie Lawrence and Dr. Surekha Davies. Both are historians of science and authors of recent books on monsters: Natalie's book is Enchanted creatures: Our monsters and their meanings. Surekha's book is Humans: A monstrous history. Here, Surekha, Natalie, and I talk about monsters as category breakers and boundary walkers—and about how monstrosity is in the eye of the beholder. We walk through a menagerie of monsters—from the apocryphal blemmyes of old travelogues, to a hairy-faced girl in 16th century France, to the figure of Caliban in The Tempest. We discuss the psychological and cultural forces that generate monsters. And we talk about whether anyone would want to live in a world without them. Along the way, we touch on the "monstrification" of social groups; psychoanalysis; our primal fear of snakes; curiosity cabinets; therianthropes and the Cave of the Three Brothers; the relationship between monstrosity and geography; our long fascination with so-called monstrous births; the Muppet Show; dinosaurs and sea creatures; and the question of what monsters might do for children in particular. Alright friends, it's the monstrous season and this is a fun one to help you celebrate. Enjoy! Notes 3:00 – Grendel's mother has often been a subject of critical discussion and adaptation. See, for instance, the 2018 novel, The Mere Wife. 12:30 – For a classic history-of-science treatment of "wonders" (including monsters) and our conceptions of nature, see here. 18:30 – For those unfamiliar with muppets, an episode of the Muppet Show, which premiered in 1976. 24:00 – The blemmyes were often the subjects of illustration—for examples, see here. 26:00 – For more on Sir Walter Raleigh and the blemmyes, see Dr. Davies' recent newsletter post. 29:00 – One example of monsters at the margins of maps can be seen in the Psalter World Map. 32:00 – For more on Cave of the Trois-Frères and the Sorcerer, see here. 34:00 – For more on shamanism, see our recent episode with Manvir Singh. 37:00 – Therianthropes are relatively rare in cave art, but have nonetheless been widely discussed. For an example, see here. 39:00 – For more on Antonietta Gonsalvus and her family, including examples of how she was represented in paintings of the era, see here. 45:00 – The trope of monsters in creation stories is often called "chaoskampf." 47:00 – The meanings of Medusa have been widely discussed and debated. See here for an example. 52:00 – For more about Caliban, and the racial and colonial dimensions of the Tempest, see here. 57:00 – The Steinbeck quote comes from his book, The Log from 'The Sea of Cortez.' Recommendations The Ashgate Research Companion to Monsters and the Monstrous, edited by Asa Simon Mittman & Peter J. Dendle Spectacle of Deformity, by Nadja Durbach The Modern Myths, by Philip Ball The Monsters and the Critics (and other essays), by J.R.R. Tolkien No Go the Bogeyman, by Marina Warner Where the Wild Things Are, by Maurice Sendak 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).

Henry Shevlin, a philosopher and AI ethicist at the Leverhulme Centre for the Future of Intelligence, discusses the transformative impact of social AI on relationships and society. He examines AI companions, from digital therapists to griefbots, raising concerns about social skills and potential dependence. Personal anecdotes reveal a broad user base, including his 81-year-old father. Shevlin advocates for regulatory measures and empirical studies to assess social AI's benefits, like privacy and skill practice, versus risks of social stunting, especially for youth.

Birds do the darnedest things. They fly, of course. They sing. They hunt in pitch darkness. They hide their food and remember where they put it. They use tools and migrate over astonishingly vast distances—sometimes even sleeping while in flight. How do they do all this? What's going on in their brains that makes these and other remarkable behaviors possible? How did their evolutionary path mold them into the incredible creatures they are today? My guests today are Dr. Andrew Iwaniuk and Dr. Georg Striedter. Andrew is a comparative neuroscientist and Associate Professor at the University of Lethbridge in Canada. Georg is a Professor of Neurobiology and Behavior at the University of California, Irvine. Together they are the authors of the new book, Bird Brains and Behavior: A Synthesis (available open access here). Here, Georg, Andrew, and I consider the deep history of birds—how they skirted the mass extinction event that felled the dinosaurs, and then radiated out into the 11,000 plus species we know today. We talk about how bird brains differ from those of mammals and reptiles—in terms of their size, but also in terms of their major structures, and in terms of their wrinkliness. We tour some of the most peculiar and perplexing bird behaviors, and consider their neural and anatomical underpinnings. Finally, we consider what we can learn from bird brains, not just about birds but about brains in general—how they evolve, how they get wired up, how they do and do not vary. Along the way we touch on barn owls, hummingbirds, megapodes, mallards, pigeons, parrots, starlings, and underestimated waterfowl; we touch on how birds' brains change with the seasons; the enduring mystery of magnetoreception; the possibility of olfactory maps; the optocollic reflex; the social intelligence hypothesis and the extractive foraging hypothesis; precocial versus altricial bird species; split-body gynandromorphy; and the future of non-invasive work in bird neuroscience. Season 7 of Many Minds is now gathering steam. We've got some great episodes in the works for you. Just a little reminder that we'd be grateful—thrilled, even—if you could help us get the word out about our show. You might do this by leaving a rating or a review, or by telling a colleague about us. We really appreciate the support, friends! Without further ado, here's my conversation with Dr. Georg Striedter and Dr. Andrew Iwaniuk. Enjoy! Notes 8:00 – For more on the deep history of the brains of birds and other vertebrates, see: Dr. Striedter's book (co-authored with R. Glenn Northcutt), Brains Through Time; this paper authored by Dr. Striedter and colleagues; and this paper authored by Dr. Iwaniuk and colleagues. 9:30 – The paper on neuron density in birds, by Dr. Pavel Němec and colleagues. 20:00 – For more about Dr. Striedter and colleagues revising some of the terminology for bird brain structures, see here and here. 24:00 – A paper by Dr. Striedter and colleagues on cortical folding. 34:00 – A recent paper describing seasonal neurogenesis in European starlings. 38:00 – A paper on the phenomenon of unihemispheric sleep across species. 42:00 – A video demonstrating the optocollic reflex in a bird. 45:00 – A paper on the puzzles of magnetoreception in birds and other animals. 51:00 – A classic paper on sound localization in barn owls. 54:00 – A paper by Dr. Iwaniuk and colleagues showing that harriers have an auditory system much like the (better-studied) owl. 58:00 – For more on place cells, the hippocampus, and cognitive maps, see our previous episode with Dr. Hugo Spiers. For more on the evolution of the hippocampus in birds and reptiles, see Dr. Striedter's paper here. 1:02:00 – For images of gynandromorphy in birds, see here and here. 1:10:00 – For a recent paper on "parental provisioning," the precocial-altricial spectrum, and brain size in birds, see here. 1:13:00 – For examples of research on the social intelligence hypothesis in birds and other animals, see here and here. 1:18:00 – For work by Dr. Iwaniuk and colleagues on some of the most interesting features of parrot brains, see here. 1:27:00 – The Avonet database. Recommendations Flight Paths, by Rebecca Heisman An Immense World, by Ed Yong [former guest!] Mind of the Raven, by Bernd Heinrich Bird Brain, by Nathan Emery Soul Made Flesh, by Carl Zimmer 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).

Dr. Marc Berman, an Associate Professor of Psychology at the University of Chicago and director of the Environmental Neuroscience Lab, discusses the profound effects of nature on mental well-being. He explores Attention Restoration Theory, differentiates between soft and harsh fascination, and highlights how natural environments rejuvenate cognitive resources. Berman shares insights from his research on how nature can improve mood and cognitive functions, along with potential benefits for mental health treatments and urban design that incorporates natural elements.