Life, free energy, and the pursuit of goals
Many Minds
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 . Kate is a philosopher at the University of Edinburgh and the author of the...
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Universal emotions in fact and fiction
Many Minds
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 , an Associate Professor of English Literature at Arizona State University. Brad is the author of a new book, ; in it he maps the landscape of debate around this long-contested topic....
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From the archive: Fermentation, fire, and our big brains
Many Minds
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 ––––––––– [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 come from? There's no shortage of suggestions out there. Some say...
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Howl, grunt, sing
Many Minds
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 , a zoologist at Cambridge University. Arik is an expert on vocal communication across the animal kingdom and the author of the recent book . Here, Arik and I talk about why the...
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The development of evolution
Many Minds
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...
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String theories
Many Minds
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 . Roope is a...
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The other half of the brain
Many Minds
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 view has faded. In our...
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A paradox of learning
Many Minds
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 magic, come away with a new understanding of the world. But how...
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From the archive: The octopus and the android
Many Minds
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...
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Your brain on language
Many Minds
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...
info_outlineIQ 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.
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