Many Minds

It's tempting to see bioluminescence as an oddity, one of those rare eccentricities of life on earth. And, on land, maybe that's true. But our planet is mostly water, and out in the open ocean bioluminescence is utterly commonplace. Creatures of all shapes and sorts sparkle and glow, glitter and pulse. But what are these displays for? Why did they evolve? How did light become the currency of the deep?

My guest today is Dr. Sönke Johnsen. Sönke is a Distinguished Professor of Biology at Duke University, where he and his research group study the vi...

There's a story about of our past that you know well. It goes like this: At some point earlier in human evolution, we started to hunt. Men in particular—perhaps channeling some deep-seated aggressive impulses—began to seek out big game. This new food source, this bonanza of calories, was what allowed our brains to expand. It changed our bodies and our societies and sent our species off on a whole new track. In short, Man the Hunter made us human. This story—told in different versions, with different points of emphasis—has circulated for decades. It's been debunked and revi...

It's kind of astonishing, really, that kids ever learn words. Each one poses a little riddle. Does this sound string refer to a person? A category of things? Or maybe some other feature of the blooming, buzzing world? And yet word learning happens. In fact, we now know it begins earlier in infancy than we realized. And we now know, further, that dogs (or at least some dogs) understand words as well. So how does this happen? What do babies and dogs really know about words? And how might we go about figuring this all out?

My...

Newton saw in the human hand proof of the divine; Darwin saw a key to our species' success. Many others, too, have described the hand in hyperbolic terms, as a paragon of design, a cornerstone of human uniqueness, an engine of our achievements. But what makes the human hand so powerful? Is it the proportions of the fingers? Is it the opposability of the thumb? Or, could it be none of this? Could it be that the real power of our hands lies—not in the physical design—but elsewhere, out of sight?

My guest today is Dr...

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!

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[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...

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...

Everyone is talking about AI these days. Often these conversations are about how AI might upend education, or work, or social life, or maybe civilization itself. But among cognitive scientists and psychologists the conversation inevitably drifts toward other questions. What does this latest generation of AI tell us about the human mind? Is it putting old ideas and theories to rest? Is it ushering in new ones? Will AI—in other words—also upend cognitive science?

My guests today are Dr. Mike Frank and Dr. Gary Lupyan. Mike is a Professor of Psychology at Stanford University, where his...

No one is an island. We all depend on each other in critical, often tangled ways. And when I say "we" and "each other" I don't just mean humans. Yes, we humans rely on other humans. But we also rely on bees, yeasts, dogs, bacteria, and countless other creatures big and small. These interspecies dependencies—or mutualisms, as biologists call them—have deflected and inflected our history. And there's no doubt they will also inflect our future.

My guest today is Dr. Rob Dunn. Rob is Professor of Applied Ecology at North Carolina State University, where he stud...

If you wanted a petri dish for understanding metaphors—how they emerge and evolve and jostle with each other—it would be hard to do better than the world of AI. We talk about AI systems variously as coaches or co-pilots, little genies or alien intelligences. Some researchers claim that AIs "grow," that they're entering their phase of "adolescence." Critics deride AI products as slop and dismiss LLMs as a kind of autocomplete on steroids. What's behind these different characterizations? Which ones are accurate and which are unfair? And are our metaphors mostly colorful rhetoric or do they matter? Are...

Humans do some pretty weird things. Some of us will sit in searingly hot rooms or jump into icy ponds. Others risk their lives trying to climb to new heights or dive to new depths. And every once in a while, two otherwise normal-seeming humans will lean in close to each other, open mouths, lock lips, and swap a hearty helping of microbes. You may even know people who've done this. But why? Are we the only animals who kiss? What could be the deeper origins of this truly bizarre behavior?

My guest today is Dr. Matilda...

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 As...

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.

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[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...

Hello there, friends! We hope you're having a restful holiday, or a lively holiday, or whatever mix of those you prefer. As the year draws to a close, we at Many Minds are taking a much needed pause ourselves. But we wanted to share with you an episode from a podcast that we've been following for some time called On Humans. It's hosted by Ilari Mäkelä. It looks at humanity from all angles to understand where we come from and where we're going. The episode we're sharing features an interview with biologist and historian of science, Matthew Cobb; he's also...

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...

Not long ago culture was considered rare in nature, maybe even uniquely human. But that's changed. We now know that the tree of life is buzzing with culture—and not just on a few lonely branches. Creatures great and small learn songs, migration routes, and feeding techniques from each other. Many species build up reservoirs of knowledge over generations. This has profound implications, not just for our understanding of the natural world, but also for our efforts to protect it.

My guest today is Dr. Philippa Brakes. Philippa is an Honorary Lecturer at the University of Exeter, wi...

Everyone loves a good evolutionary puzzle. Why do we have appendices? Why do we dream? Why do we blush? At first glance, memory would not seem to be in this category. It's clearly useful to remember stuff, after all—to know where to find food, to remember your mistakes so you don't repeat them, to recall who's friendly and who's fierce. In fact, though, certain aspects of memory—when you hold them up to the light—turn out to be quite puzzling indeed.

My guests today are Dr. Ali Boyle and Dr. Johannes Mahr. Ali is a philos...

It's hard to say exactly when, but some tens of thousands of years ago, our best friends were born. I'm referring, of course, to dogs. This didn't happen overnight—it was a long process. And it not only changed how those canids behaved and what they looked like, it also changed their brains. As wolves gave way to proto-dogs, and proto-dogs gave way to dingoes and dalmatians and Dobermanns and all the rest, their brains have continued to change. What can we learn from this singular saga? What does it tell us about dogs, about domestication, and about brains?

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...

AI therapists and caregivers. Digital tutors and advisors and friends. Artificial lovers. Griefbots trained to imitate dead loved ones. Welcome, to the bustling world of AI-powered chatbots. This was once the stuff of science fiction, but it's becoming just the stuff of everyday life. What will these systems do to our society, to our relationships, to our social skills and motivations? Are these bots destined to leave us hollowed out, socially stunted, screen-addicted, and wary of good-old-fashioned, in-the-flesh human interaction? Or could they actually be harnessed for good?

My guest today is Dr. Henry Shevlin. Henry is...

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...

One afternoon you decide to snub your responsibilities and go for a hike. You spend a few hours in the woods or the mountains. You study the bark of trees, you bathe in birdsong, you let your eyes roam along a distant ridgeline. And you come back feeling better, restored somehow—like you have more energy, more patience, more bandwidth. We've all, I'm guessing, had experiences like this. But what's behind these effects? Why would nature restore us? What's the evidence that it really does? And what is even being restored, actually?

My guest today is Dr. Ma...

Hi friends!

We're taking a much-needed summer pause—we'll have new episodes for you later in September. In the meanwhile, enjoy this pick from our archives!

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[originally aired June 1, 2023]

There's a common story about the human past that goes something like this. For a few hundred thousand years during the Stone Age we were kind of limping along as a species, in a bit of a cognitive rut, let's say. But then, quite suddenly, around 30 or 40 thousand years ago in Europe, we really started to come into our own. All of...

Hi friends!

We're taking a much-needed August pause—we'll have new episodes for you in September. In the meanwhile, enjoy this pick from our archives!

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[originally aired February 8, 2024]

Where do memories live in the brain? If you've ever taken a neuroscience class, you probably learned that they're stored in our synapses, in the connections between our neurons. The basic idea is that, whenever we have an experience, the neurons involved fire together in time, and the synaptic connections between them get stronger. In this way, our memories for those experiences become mi...

Hi friends!

We're taking a much-needed August pause—we'll have new episodes for you in September. In the meanwhile, enjoy this pick from our archives!

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[originally aired May 30, 2024]

Maybe your idea of spiders is a bit like mine was. You probably know that they have eight legs, that some are hairy. Perhaps you imagine them spending most of their time sitting in their webs—those classic-looking ones, of course—waiting for snacks to arrive. Maybe you consider them vaguely menacing, or even dangerous. Now this is not all completely inaccurate—spiders do have...

When you hear the word "shaman," I'm guessing a web of associations starts to form in your mind. Perhaps you imagine strange ceremonies and strong substances; maybe you think of an earlier time when magic and superstition reigned. But shamanism is not just some relic of the past, or a curio from exotic lands. It's part of our present, and it will almost certainly be part of our future. This is because the roots of shamanism lie within us all.

My guest today is Dr. Manvir Singh. Manvir is an Assistant Professor of Anthropology at the University...

Childhood is a special time, a strange time. Children are adored and catered to—they're given their own menus and bedrooms. They're considered delicate and precious, and so we cushion them from every imaginable risk. Kids are encouraged to play, of course—but very often it's under the watchful eye of anxious adults. This, anyway, is how childhood looks in much of the United States today. But is this the way childhood looks everywhere? Is this the way human childhoods have always been?

My guests today are Dr. Dorsa Amir and Dr. Sheina Lew-Levy. Dorsa is an Assi...

AI will fundamentally transform science. It will supercharge the research process, making it faster and more efficient and broader in scope. It will make scientists themselves vastly more productive, more objective, maybe more creative. It will make many human participants—and probably some human scientists—obsolete… Or at least these are some of the claims we are hearing these days. There is no question that various AI tools could radically reshape how science is done, and how much science is done. What we stand to gain in all this is pretty clear. What we stand to lose is less obviou...

Puppies wrestling and mock-biting each other. Toddlers playing hide and seek. Kittens pouncing—repeatedly—on a toy mouse. You've no doubt looked on at scenes like this with amusement. And you've no doubt seen some of those viral videos—of ravens sledding down hills, of bumble bees playing with balls. All these moments make us smile, maybe even giggle. But the scientific questions they raise merit serious attention. Where do we see play in the animal kingdom? Where do we not? What functions does play serve? Do we—and many other creatures—have an elemental need for play?

My gues...

If you've heard anything about the study of human personality, you've probably heard about the "big five." This is a framework that attempts to characterize human personality in terms of five broad factors or dimensions—neuroticism, extraversion, openness, conscientiousness, and agreeableness. The big five framework has been enormously influential, generating heaps and heaps of data, and study after study on the stability of personality, on the factors that shape our personalities, on how our personalities predict success and satisfaction. But is the big five really the best we can do? What does it miss? What does it mask? Where sh...

Some call it the "psychedelic renaissance." In the last decade or so, interest in psychedelic drugs has surged—and not just among Silicon Valley types and psychiatrists and neuroscientists. It's also surged among a stereotypically soberer crowd: academic philosophers. The reasons are clear. With their varied and sometimes transformative effects, psychedelics raise ethical questions, epistemological questions, metaphysical questions, questions about the nature of experience and the nature of the mind.

My guest today is Dr. Chris Letheby. Chris is a philosopher of cognitive science at the University of Western Australia and the author of the 2021 book, Philosophy of...

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? An...

You've probably come across the "free energy principle." It's become one of the most influential ideas in the broader cognitive sciences. Since the neuroscientist Karl Friston first introduced it in 2005, the theory has been fleshed out, extended, generalized, criticized, and cited thousands and thousands of times. But what is this idea, exactly? What does it say about the nature of brains and minds? What does it say about the phenomenon of life itself? And is anything that it says really that new?

My guest today is Dr. Kate Nave. Kate is a philosopher at the University of...

Are human emotions universal? Or do they vary from one place to the next and from one time period to the next? It's a big question, an old question. And every discipline that's grappled with it brings its own take, its own framings and forms of evidence. Some researchers appeal to cross-cultural experiments; others turn to neuroimaging studies or conceptual analysis. Some even look to fiction.

My guest today is Dr. Bradley Irish, an Associate Professor of English Literature at Arizona State University. Brad is the author of a new book, The Universality of Emotion: Perspectives from...

Hi friends,

We're taking care of some spring cleaning this week. We'll be back in two weeks with a new episode. In the meantime, enjoy this favorite from our archives!

- The Many Minds team

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[originally aired February 22, 2024]

Brains are not cheap. It takes a lot of calories to run a brain, and the bigger your brain, the more calories it takes. So how is it that, over the last couple million years, the human brain tripled in size. How could we possibly have afforded that? Where did the extra calories com...

The tree of life is a noisy place. From one branch come hoots and howls, from another come clicks and buzzes and whines. And coming from all over you hear the swell of song. But what is all this ruckus about? Why do so many animals communicate with sound? What kinds of meaning do these sounds convey? And—beyond the case of human speech—do any of these sounds merit the label of "language"?

My guest today is Dr. Arik Kershenbaum, a zoologist at Cambridge University. Arik is an expert on vocal communication across the animal kingdom and...

Evolution is not what it used to be. A lot has changed since Darwin's day. In the first half of the 20th century, evolutionary theory was integrated with an emerging understanding of genetics. Late in the 20th century, biologists started taking seriously the idea that organisms don't just adapt to their environments, they change them. Recently, researchers have started to acknowledge the role of culture in evolutionary processes. And so slowly our understanding of evolution has been reconsidered, updated, expanded. And more updates are underway. But it's not just our understanding of evolution that has changed over time. Evolution...

Where would our species be without string? It's one of our most basic technologies—so basic that it's easy to overlook. But humans have used string—and its cousins rope, yarn, cordage, thread, etc.—for all kinds of purposes, stretching back tens of thousands of years. We've used it for knots and textiles and fishing nets and carrier bags and bow-strings and record-keeping devices. It's one of the most ubiquitous, flexible, and useful technologies we have. But we haven't only put string to practical purposes. We've also long used it to tickle our minds.

My guest today is Dr...

Neurons have long enjoyed a kind of rock star status. We think of them as the most fundamental units of the brain—the active cells at the heart of brain function and, ultimately, at the heart of behavior, learning, and more. But neurons are only part of the story—about half the story, it turns out. The other half of the brain is made up of cells called glia. Glia were long thought to be important structurally but not particularly exciting—basically stage-hands there to support the work of the neurons. But in recent decades, at least among neuroscientists, that v...

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 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, as if by mag...

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

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[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...