The One You Feed - Kevin Mitchell on The Genetics of Personality

Episode Date: May 10, 2022

Kevin Mitchell is an author and an Associate Professor of Genetics and Neuroscience at Trinity College Dublin. His research is aimed at understanding the genetic program specifying the wiring of the brain and its relevance to variation in human faculties. Kevin is also the author of the science blog, Wiring the Brain, and a number of books and publications.In this episode, Eric and Kevin discuss his book, Innate: How the Wiring of Our Brains Shapes Who We Are.But wait – there’s more! The episode is not quite over!! We continue the conversation and you can access this exclusive content right in your podcast player feed. Head over to our Patreon page and pledge to donate just $10 a month. It’s that simple and we’ll give you good stuff as a thank you!Kevin Mitchell and I Discuss the Genetics of Personality and…His book, Innate: How the Wiring of Our Brains Shapes Who We AreThe missing third component in the Nature vs. Nurture debateInnate Underlying Traits in the Brain: Extroversion, Neuroticism, Conscientiousness, Agreeableness, Openness to ExperienceThe relationship between genetics and neurobiologyWhat “neurons that fire together, wire together” actually meansThe difference between Personality Traits and Character TraitsThe impact of parenting on underlying Personality TraitsHow people differ in the amount of “free will” that they haveThe connection between genetics and addictionThat we become ourselves throughout lifetimeKevin Mitchell links:Kevin’s WebsiteTwitterWhen you purchase products and/or services from the sponsors of this episode, you help support The One You Feed. Your support is greatly appreciated, thank you!If you enjoyed this conversation with Kevin Mitchell, you might also enjoy these other episodes:Integration of Science and Wisdom with Jeremy LentNeuropsychology and the Thinking Mind with Chris NiebauerSee omnystudio.com/listener for privacy information.

It's true that our genes influence our personality traits and that our personality traits influence our behavior, but it's not true that our genes determine our traits or that our traits determine our behavior. And that's the distinction that I think is really important because it gets away from the idea that we have no control. Welcome to The One You Feed. Throughout time, great thinkers have recognized the importance of the thoughts we have. Quotes like, garbage in, garbage out, or you are what you think, ring true. And yet, for many of us, our thoughts don't strengthen or empower us. We tend toward negativity, self-pity, jealousy, or fear.

We see what we don't have instead of what we do. We think things that hold us back and dampen our spirit. But it's not just about thinking. Our actions matter. It takes conscious, consistent, and creative effort to make a life worth living. This podcast is about how other people keep themselves moving in the right direction. How they feed their good wolf. I'm Jason Alexander.

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follow us on the iHeartRadio app, Apple podcasts, or wherever you get your podcasts. Thanks for joining us. Our guest on this episode is Kevin Mitchell, an author and associate professor of genetics and neuroscience at Trinity College, Dublin. His research is aimed at understanding the genetic program, specifying the wiring of the brain and its relevance to variation in human faculties. Kevin is also the author of the science blog called Wiring the Brain and the author of the book discussed here, Innate, How the Wiring of Our Brains Shapes Who We Are. Hi, Kevin. Welcome to the show. Thanks very much. Thanks for having me. I'm really excited to have you on. We're going to be discussing your book,

Innate, how the wiring of our brains shapes who we are. But before we get into that, we'll start like we always do with the parable. There's a grandparent who's talking with their grandchild and they say, in life, there are two wolves inside of us that are always at battle. One is a good wolf, which represents things like kindness and bravery and love. And the other is a bad wolf, which represents things like kindness and bravery and love. And the other is a bad wolf, which represents things like greed and hatred and fear. And the grandchild stops and thinks about it for a second, looks up at their grandparent and says, well, which one wins? And the grandparent says, the one you feed.

So I'd like to start off by asking you what that parable means to you in your life and in the work that you do. Well, it's a great question. And, you know, since you had emailed me that link and I looked at it, I thought about it a bit. And actually, it really resonates with clearly just, you know, in personal life. Anyway, I think it would resonate with everybody in terms of questions about how we choose actively to live our lives, not just the momentary decisions that we make, but the kind of policies that we have about the momentary decisions that we make, but the kind of policies that we have about the types of decisions we'll make over longer timeframes. And that's something that I've been thinking about both in the writing of the book Innate and the one I'm working on now, which is about agency and free will, especially in response to people who look at the fact that

some of our psychological traits have a genetic basis to them, which we'll talk about, and think, therefore, that there's nothing we can do about it. Something is in our DNA, and we're just wired that way, and we're not an active agent in that process at all. And I think that's not right. It's true that we are shaped a certain way, we are wired a certain way, but that's only a baseline. And I think our character emerges through our lifetimes very much based on the decisions that we actively make ourselves through that process. So for me, it struck a chord there with ideas that I've been thinking about and writing about. Yeah. As I look at your book, Innate, and also your upcoming book,

which you sent me a proposal for and I got to read. It feels to me like your work is trying to strike a middle ground between on one hand, sort of, as you said, determinism, people who are saying we're just machines and we act out the programs that are put in us and that's it. There's no free will. And then on the other hand, what I might call the human potential movement, which says you can be anything you want, right? And I feel like you're kind of staking out a middle position that says, look, you know, there actually is a fair amount of the way we are that's because of the way we are wired. And we're going to talk about how that wiring happens here in a minute. So a fair amount of it is that, but that's not the entire story. And there is some

ability to have control of our thoughts, our emotions, our behavior. Yeah, I think that's right. And I mean, thanks for saying that, because I think that's exactly what I'm trying to do is stake that middle ground, because those two positions you articulated are too extreme. You know, it's not the case that we can just be anything we want to be or completely overwrite our innate predispositions. But at the same time, it's also not true that those innate predispositions control everything about us in any given moment or indeed over the trajectory of our lives. They're not just like the tunings of a robot that will absolutely determine what it does at any moment. a robot that will absolutely determine what it does at any moment. They're a baseline for us that does influence the way that we interact with the world. But I think one of the real themes

of innate and also all of the work really is about thinking about the relationship, especially between our genes and our traits, as a trajectory. There's not a direct linear correspondence between those things. There's an influence over our lifetimes in conjunction with all of the experiences that we have and the environments that we are exposed to and everything else. So it's very much an interactive kind of picture, which in one sense is a little frustrating because it means the picture is just, it's not a simple picture, right. You know, it's complex and it's nuanced. But I think it's also just more realistic. Yeah. And so the debate that most people hear is nature versus nurture.

Right. And that's what we're sort of talking about here on one hand. It's my genes or it's my environment. Which is it? Right. And I think any intelligent person now would go, well, it's certainly both. I think any intelligent person now would go, well, it's certainly both. But you actually make a point that there is a third component to this that we're missing when we oversimplify down to nature and nurture. Can you share a little bit what that third component is? Sure. Yeah. I mean, so the nature-nurture debate, you know, really goes back to the question of whether a child is just born the way they're going to be or whether their upbringing really

shapes them. And I think any parent who's had, certainly who's had more than one child, knows that they come different. They're not blank slates. So the idea that everything about us is shaped by our environment and upbringing just doesn't fit with our common experience. And also the scientific evidence shows that that's just not true. But at the same time, it's also not the case that the predispositions that are genetics, if you think of nature as corresponding to genes, which is that correspondence often drawn, that's not the whole picture because you can see two people who have the exact same genes, so identical twins, whose personalities and cognitive and psychological functions

may be clearly different from each other. We can see that in humans, but you can see that in experimental animals in biology and neuroscience, where most of the work that's done on mice, for example, is done on genetically identical mice. And yet there's variation from individual to individual, even in incredibly tightly controlled environmental conditions as well. So it turns out that a lot of that variation just comes from the way that the brain develops. So if we think within the DNA of a fertilized egg, single cell fertilized egg

that we all start out life as, there's a sort of a program in effect for making a human being with a human brain. And that program brings along with it the aspects of human nature that differentiate us from chimpanzees or aardvarks or tigers or any other animal. But the relationship between the information in the genome and the end product is not like a blueprint. You can't look in the genome and say, it says to make this many cells here and make those connections like that. There is no sort of correspondence. It's more like a blueprint. You can't look in the genome and say, you know, it says to make this many cells here and make those connections like that. You know, there is no sort of correspondence. It's more like a recipe. And the consequence of that is that the recipe doesn't specify the end product. It just specifies a series of processes or steps to make the thing. And so, you know, I like to say you can't bake the same cake twice. It doesn't

matter how good your recipe is. There's going to be some randomness in the way this stuff gets mixed and the way it gets cooked in the oven that produces some variation in the outcome. That's true for our brains as well. The genome just doesn't specify everything about the way your brain is put together. It just specifies the rules. And then all these complicated processes happen that just have some variability intrinsic to them, which is then a third source of variation besides genes and environment, development itself, the process by which genetic information is realized to make an individual, that adds variation as well. So basically what you're saying is if you were able to do this, maybe you are able to

do this for all I know, if you were to take an identical egg and sperm that formed me and you took both those and you said, all right, here you go, go make Eric, what they make would be slightly different. Absolutely. Yeah. Because the path of development would be slightly different. Exactly right. I saw something recently, an article about a woman who was complaining that she had spent $25,000 to clone her cat. And it turned out she got a cat with a totally different personality and character and everything else, which was sort of funny to me because it was obvious that that was going to happen. You know, what makes us a person, an individual is not just our DNA. If it were, then identical twins would be effectively the same person. And obviously they're not. Even

from the moment they're born, the brains of identical twins are already clearly different from each other. And we can see that with neuroimaging and so on. So yeah, right from the get-go, there's already some differences in the way that that genetic information gets expressed in any individual run of the program. If we were to group these things, nature, nurture, and development, though, we would say that nature, genetics, development, those two things are what you would call innate, right? Yeah. You know, they make up part of who we are. We're not going to intervene in any meaningful way in those things. I may be taking a leap with that last statement. Yeah. The intervention bit is a slightly separate question, a little tricky, and it's probably not one answer for everything. So what we can do if we want to understand where

variation comes from in some, say, personality traits, right? You know, we can kind of measure various personality traits in different people. And I mean, that's a bit arbitrary. We put a number on things like extroversion or neuroticism or risk-taking or shyness, whatever, you know, all those kinds of things. So say we measure something like that. And then when we look across the population, we see there's a certain amount of variation in the population, exactly the same as if we measured height and we see the typical sort of bell curve of lots of people in the middle and fewer people at the extremes. variation in genes or variation in environment. And mathematically, you can try and distinguish those and see how much of an effect or how much of a contribution, say, genetic differences make to those kinds of traits. And when people have done that using things like twin studies and family studies, what they typically find is that maybe 40 to 50% of the variance that we see,

sort of the width of the bell curve, if you like, is attributable to genetic differences. And one way to think about that is if everybody was a clone, the bell curve would be much, much narrower, right? Which you can imagine for height, that makes sense. But it wouldn't be zero. I mean, there'd still be some variation left. And then the question is, how much of that variation is due to specific experiences or environmental influences or family upbringing versus maybe developmental variation? And one of the sort of surprising findings from a lot of these twin and family studies was that the family environment doesn't seem to affect these traits very much.

It doesn't really affect how extroverted or neurotic or conscientious you are, which was a surprise. And you could see that by looking at people who are adopted, for example, who share no extra resemblance with their adoptive siblings than they do with anybody else on the planet, basically. I mean, it really says parental upbringing there is not having much of an effect. And even twins who are reared apart, it's sort of the opposite experiment. You take identical twins who are reared in different families, and it turns out they're about as similar to each other as they would be if they had been reared in the same family. So the message seems to be that parenting doesn't have much of an influence on those kinds of traits.

It's important to nuance that bit because those are precisely the type of traits that psychologists have defined in a way like they're sort of hardwired biological aspects of an individual. If, say, 50% of the variance is due to genetic differences, and then the family environment doesn't make much of a difference at all, then you're left with this question, well, what's the rest? Where's the rest of that variation coming from? And what I think is that a lot of that is just developmental variation. And the upshot of that is that many of those traits are even more innate than it looks like they are just from the genetics alone. There's a possibility to look at the results from twin studies and say, oh, it's only 50% genetic. The rest must be

experience or environment. But that's not necessarily true. It could be just developmental, in which case a lot of that is still innate. And then we get into other questions about what does it mean to have innate predispositions and how do they influence behavior? about what does it mean to have innate predispositions and how do they influence behavior? Yeah. Let's move there next. Let me sum up to where we are now. What we're saying is that you're arguing there's a pretty fair amount of our underlying traits that are innate. What the exact numbers are, nobody knows, but there's a lot of innateness in us. And again, anybody, common sense would show us to be the case. I mean, there's a nateness in dogs, right? I mean, you could just tell.

You've got different personalities, right? Absolutely, yeah. So let's talk a little bit about what do we mean when we say underlying traits or predispositions? What are we saying when we talk about those? Yeah, it's a great question. And it's really key to, I think, undercutting a misunderstanding. Yeah, it's a great question. And it's really key to, I think, undercutting a misunderstanding. So in personality psychology, what psychologists try to do is look for patterns across the behavior of many, many different people across many, many different contexts. So they're really trying

to abstract away all the particulars of any individual's life so that they can look for dimensions along which people tend to vary in their behavior. In the English language, for example, there's about 8,000 words that describe something you would call a personality trait or a character trait or something like that. So you could say someone is stubborn or strong-minded or strong-willed or obstinate or, well, there's a whole load of other more insulting terms you could use depending on whether you're being positive or negative. But when you look at those terms, what you find, I mean, the examples I just gave you, it's kind of obvious that actually they're all tapping into the same thing. If people vary in stubbornness or obstinacy or any of those other words, really that's all the

one thing, right? And so what personality psychologists have tried to do is say, well, how many things are there like that? How many dimensions are there that characterize people's behavior sort of independently from each other? That is, the dimensions are independent from each other. And there's lots of ways you can carve that up. I mean, the ancient Greeks had the four humors of bile and melancholy and these sorts of things. You can have two or five or 10 or 16 or 30 different dimensions. But the most popular ones are the big five, extroversion, neuroticism, conscientiousness, which all kind of mean what the colloquial meanings sound like. And then

agreeableness, which makes intuitive sense. And then the last one is openness to experience, which is sort of about imagination and creativity, openness to ideas and so on. And those things together capture a lot of these basal dimensions along which people vary. And they seem to, in some way that's not well understood, reflect differences in the way the brain is wired. So really, when you're talking about personality, what you're saying is that people have a tendency to act in a certain way across many different contexts. And really, it comes down to decision making. So in any given context, we're going to understand what the context is, use our knowledge and our experience to know kinds of options that we might have.

But then I might, if I'm, say, less extroverted than you, I might tend to choose one option more than you would, because I'm slightly tilted that direction, if you know what I mean. So that's the way that I think of those, is sort of tunings of these basal parameters in the brain. Although if you get into the neurobiology of it, what's interesting is that there isn't clear neurobiology of, say, conscientiousness or neuroticism or extroversion. There is a neurobiology of things that feed into them. So risk aversion, for example, is something that we can measure even in animals. You can measure how risk averse

a mouse is compared to another mouse. And we can go into the brain and tweak the neural circuits that we know in some way modulate that and change how risk averse an animal is. So there's a biology of decision-making that has a lot of these underlying parameters, like how sensitive you are to rewards or threats or punishment, how confident you have to be before you make a decision, how long you're willing to wait for a reward, how averse you are to risks, and how interesting you find novel things, all of those things. They can feed into these sort of statistical constructs, which is really what those personality traits are. So the idea is that we have some of these basal tunings. Our brains are really slightly tuned one way or another. And then the question is, how does that actually manifest on

our behavior on a moment-to-moment basis? And there, I think you have to get into understanding the actual context of particular people in actual situations, right? Because the personality psychology abstracts away all of that idiosyncratic detail. But of course, we're never behaving in just any given situation. We're always behaving in some particular situation. And we're not just abstracted collection of personality traits. We're ourselves with all of our knowledge and experience and everything else. And so those predispositions are the starting point. But as we go through our lives, we adapt to our environments. We create, in fact, our own environments. We select them over time.

And we make decisions about our own behavior and our own behavioral patterns over time. And we develop habits that actually most of our behavior on a moment-to-moment basis is really habitual. We may have habits of behaving one way or another that have been informed over the course of our lives by whether we're more or less extroverted or neurotic, But right now, they're not being controlled by those traits, if that makes sense. Totally. I want to jump back to something you said there and make a point that I think you make in the book. And I think it's an interesting one, which is you're talking about, say something,

a tendency towards more or less risk aversion, right? When we hear that these things are quote-unquote genetic, those of us who are at least like me, who don't know that much, think, oh, okay, let's find the gene for risk aversion. And you make the point that it's a whole lot more complicated. You used a phrase there, the neural circuits. So talk about the relationship between genetics and something as complicated as a neural circuit. And what do we know about how those inform each other or create each other? Yeah. So there's two sides to that.

One is something I've been working on for a long time, and there's a whole field of developmental neurobiology, which is just trying to understand what are the instructions for making a brain? How do they actually work? When an embryo is developing, the brain gets set aside, you make nerve cells. They have to be arranged in really, really specific ways in different parts of the brain. You know, all these regions people will have heard about the cortex and the hippocampus and the cerebellum, and there's thousands and

thousands of these. They're all really, really very different from each other, and they have their own sort of computational architecture and layout of neurons and connectivity within them. And then, of course, they all have to be connected up to each other in really stereotyped ways. So there's basically instructions encoded in the genome that specify at least the processes by which all of that wiring self-assembles. I mean, the amazing thing is it does it itself, right? There's no one in charge telling it what to do. It's this self-organizing system. And of course, that's what billions of years of evolution will get you, is this amazing thing, right? But at the same time, because that system develops based on these genetic instructions, and because we all have different genetics, right? Because genetic variation just happens every time a sperm or an egg cell is created, some new mutations happen.

So genetic variation enters the population, which is why we have diversity of human beings that we see. So what that means is that we then get some variation in the way the brain develops, right? There may be slightly more cells here, slightly more connections there. And so the wiring of these things differs between people. And in some ways that are really, really complicated and complex and not well understood, that wiring manifests as our psychological traits. But you're right in saying that there isn't a very direct or specific relationship. So first of all, most of our complex behavior can't be

tied to one part of the brain or another. That's really just a sort of an old-fashioned simplistic idea saying, oh, you know, I'm doing this with just this part of my brain or that part. It's all circuits. It's all interconnected. It's distributed brain systems. And then, you know, on the genetic front, it's also not the case that just one gene

specifies one part of the brain. It's loads of genes working together. And so it's complexity all the way down, which is a little bit frustrating if you're trying to make simple stories, if we have a gene for intelligence or a gene for neuroticism or something like that. It just turns out that mostly when we find those genetic variants, they're just generally sort of affecting how the brain develops. And that doesn't unfortunately tell us an awful lot about the biology of intelligence or social interactions or things like that. Those are really complex things. And the answer to understanding how they work is not in the genetics, even though differences in genes affect them. I'm Jason Alexander.

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There's a phrase, genetics load the gun, environment pulls the trigger. Have you heard that phrase before? Yeah, yes, I have, yeah. What do you think of that phrase? I guess it depends on the context that it's applied to. Okay. Say for something like intelligence, right? Which is obviously a really hot button topic. I would say that people differ in their intellectual potential and whether they reach that potential is everything to do with education and environment and the opportunities that they're given. You could say the same for height. You could say the same for athletic skills or musical ability. You know, there's some innate differences between people,

but then the environment and experience obviously hugely feed into the actual outcome in any person. So for me, the right way of thinking about it is as an interaction along or across an extended trajectory, not just a momentary kind of thing. While I'm trotting out well-known phrases about genetics and neurology, I'm going to bring out another one, which is neurons that fire together, wire together. Hebb's law. Yes, which is great. It's attributed to Hebb, but actually it was a mentor of mine, Carla Schatz, who I think actually coined that term. But the idea is that brains are there to learn. So there's nothing hardwired about them, really. There's nothing completely

hardwired about them. They come sort of pre-wired, but they're pre-wired to learn. And so a lot of the ways in which we learn are one of the simplest ways, anyways, by associating two things. So, you know, this might be Pavlov ringing his bell and the dog associating it with food, right? You know, in the lab, it's often a tone and a mouse getting an electric shock or something like that, or an odor, you know. So, if you pair two things like that, then the neurons that represent them, if they're firing at the same time and they're connected, either directly or they're both connected to a third brain area, then they can strengthen those connections. And that we think is in some way the physical basis for a memory. And you can see that even in the simplest of organisms, things like sea slugs, where they can habituate to their environment or they can learn to associate very simple things

over time. And so the neurobiology of that is really well understood. And of course, you know, in human beings, the things we learn over our lifetime are, you know, things like facts, right? We learn facts, we learn the properties of objects, we learn that a cat is a type of mammal, and Felix is a particular cat. And, you know, so we learn sort of categorical relations between things. We learn causal relations between things. That's how we come to understand the world. We know that if I don't feed Felix, he's going to die. That sort of thing. Sorry for the slightly grim example. But no, no, no problem. Felix is done. Felix is done. So we've learned from that.

The next cat. That's right. That's right. Next cat will be well tended to. Yeah, exactly. So yeah, I mean, the idea that, say, neural plasticity, there was a big hullabaloo about this, you know, maybe, I don't know, 15, 20 years ago, and people suddenly started to say, oh, look, the brain is plastic. Well, yeah, of course it's plastic. That's what it's for. That's how it learns. I never could quite understand what the surprise was over that. But again, it doesn't mean everything in the brain is plastic. It doesn't mean you can overwrite these predispositions that are pre-wired in there. But what we do learn is how to adapt to our environments. We learn to do particular behaviors because we know that's a good thing to do in this situation, even if it goes against some of our innate personality traits. For example,

shy people can learn to be perfectly good public speakers, even though it may exhaust them, as opposed to energizing them in the way that it would somebody else. One of the interesting things, I think, when we think about the limits of personality traits and the idea that they don't determine our behavior, but they influence it, is thinking about this distinction between personality and character traits. Those personality traits that have been defined in the field of personality psychology are designed to be these things that are abstracted away, as I said, from the details of experience. They're sort of overarching patterns. And they're neutral, right? It's not better or worse to be more or less conscientious or more or less neurotic or more or less extroverted.

At least it's not better or worse in every scenario you could find yourself in. Right. But then there's character traits, which are very different. And there are things like the ones that you talked about in the parable of kindness or greed or bravery or loyalty or temperance or justice. And those are things that philosophers have been talking about since the time of Aristotle and Cicero and people like that. And when they've talked about them, there's a moral aspect to them. They're seen as virtues or vices. They're good or bad aspects of our behavior. And it's always been the case, again, from Aristotle and Cicero on up, that they're not just things that happen to us, right? We have a

hand in them. We take some control. We have some responsibility for developing those character traits over our lifetime. And again, they may be influenced and informed in a certain way by our psychological predispositions. And of course, they're in some way reactive to our environments and experiences. But also, we ourselves make decisions to act in a certain way over our lifetimes. So we're sort of pre-deciding things, not particular decisions, just ways of behaving that in effect constrain our future selves along a path that we have decided is a good one. And of course, sometimes that's us deciding it. When we're young, it's our parents influencing us saying, don't hit Billy or share your food with Emma or whatever it is, trying to inculcate some positive

character traits and behaviors. And of course, there's societal and cultural, and for some people, religious or other sort of institutional norms and expectations that come into play that inform that arc of character development as well. Yeah, I think that's a really helpful distinction. And you brought up parenting again, and I kind of want to swing back around to that because you said before, look, it doesn't appear from the data that parenting has a real big impact on underlying personality traits. But you're not saying that parenting doesn't have an impact on the people we turn out to be in the lives that we live.

You're saying it's not changing that innateness. But obviously, we all know if you've got a parent who abuses you, you're going to have a very different life than somebody who has a parent who doesn't. Yeah. Potentially, right? Yeah, absolutely. Absolutely. And I think that's been a misunderstanding of the surprising result from behavioral genetics that does show parents don't influence those innate underlying traits. It seemed to indicate wrongly that parents don't influence our behavior at traits, it seemed to indicate wrongly that

parents don't influence our behavior at all, or parenting doesn't matter. You know, that was a sort of a shorthand message, which I think is absolutely wrong and just over-interprets the basic result. I think it's exactly as you've said, that parenting, you know, affects all kinds of aspects of our behavior without necessarily rewiring those underlying traits. Those are just the basis. That's just the basement level of the building. And as we go through our lives, the examples that we're given, the expectations that we're set, the encouragement we get, or on the other hand, neglect or abuse or any of the unfortunate negative aspects of parenting as well,

absolutely can shape these adaptations that we make, our so-called characteristic adaptations to the world, which include ways of being, ways of behaving that we call character traits, once they get crystallized through time. And actually, I came across a really nice quote recently, which is a bit apocryphal, but I saw it ascribed to someone named Lao Tzu, who was an ancient Taoist Chinese philosopher. And it goes something like, watch your actions, they become habits. Watch your habits, they become character. And then I think it was, watch your character. It becomes destiny. To me, that captured a lot of the idea that we ourselves are making these decisions. And every decision we make can reinforce our own behavioral habits in good or bad ways.

So, yeah, I think it's true that our genes influence our personality traits and that our personality traits influence our behavior. But it's not true that our genes determine our traits or that our personality traits influence our behavior, but it's not true that our genes determine our traits or that our traits determine our behavior. And that's the distinction that I think is really important because it gets away from the idea that we have no control, that it's just in my DNA, I couldn't help it that way, it's my genetics. That's true only up to a certain point. Yeah. This distinction that we're talking about is one that's of key interest and importance to me. And what we're really talking about, I think, is how much choice do I have? How much free will do I have?

And I think this is a really interesting question. And a little background on me i'm a recovering alcoholic and heroin addict so i've been in my life in places where it felt like the amount of free will that i had to make a choice felt radically different to me yeah you know two days after having had a drink of alcohol when i'm addicted to alcohol the amount of free will or choice i have feels radically different than it does to me 15 years later. And we could certainly say some of that is just the physiology of what alcohol is doing in my body. But let's broaden that out a little bit and talk about, you know, how much,

or let me say this differently. We can't say like, well, how much free will does somebody have? Like who's the somebody and what's the circumstance? So talk to me about how you think about that idea of degrees of free will or choice. Yeah, it's a great question. It's one that I'm really interested in, and it's largely what my new book is about. Looking at free will, the question of free will, first of all, do we have it at all? Do humans have free will? Is it a real thing or is it an illusion? I think, you know, it's popular these days to kind of say, oh, you know, neuroscience or even genetics or psychology has shown that we don't have free will. We just, our brain makes a decision and then maybe it informs us about it and we make up some reason about it. But really it's all just physical stuff

happening in our brains. I think that's not right. I think it is true that we as agents, and this extends to animals and things as well, really do make decisions. And we really have causal power in the world as an entity, right? We're not just pushed around by things in the environment. And we're also not just pushed around by our own parts. We're not just a place where complicated things happen, right? We're in the driver's seat for a lot of the time. However, that doesn't mean we have complete absolute freedom, right? Which is a kind of a nonsensical, incoherent notion when you dig into it a bit. Some people would want to say, well, unless I can act unconstrained by any prior cause,

then I'm not really free and I don't have free will. And to me, that doesn't really make any sense because acting for no cause also means acting for no reason, you know, on the basis of no information, just doing things at random. If living organisms did that, we'd never have evolved. The whole point of life is doing things for its own reasons to keep itself going, right? And we come from millions and millions and millions of years of evolution of life that has done that. So living things do things for their own reasons. And that's where agency, I think, can be found.

You know, if you get into the biology of that and you get into the biology of decision making, how do we actually make a decision? Then you can see there's all kinds of things going on, all sorts of different neural systems at play at the same time. So we will look at a situation, we perceive a load of things, we map what's out in the world, we look for threats and opportunities, we have various goals, we monitor our own internal state to see, am I hungry? Am I thirsty? What do I want to do? We prioritize some goals versus others. We kind of run through in our minds a set of possible

options, and then we weigh them up and decide, well, which is going to give me the best outcome here, either in the short term or the long term, and so on. So there's really, really complicated processes going on there. And not surprisingly, those things actually vary between people. So they vary in terms of, say, risk-taking. That's a parameter that feeds into decision-making and how much control you have. But also the level of sort of rational conscious control that we're each able to deploy, that's a trait that can differ between people. And actually, in an obvious way, you can see that it develops across the lifetime, because babies don't have any rational conscious control. It's a skill, actually, that has to

develop and that can be worked on and has to, you know, as we mature. But, you know, some people are more patient than others. Some people are more perseverant than others, and so on. So, you know, some people are more patient than others. Some people are more perseverant than others and so on. So, you know, for me, one of the pieces of evidence that free will is a real thing is that people clearly differ in how much free will they have in a psychological sense. Some people are very able to control themselves. They're not impulsive. They plan over a longer time frame. They're able to prioritize longer-term goals over shorter-term ones and so on, and other people the opposite.

But then also, depending on our situations, if we're tired or hungry or if we're intoxicated or any of those things, of course, they can change that. So the amount of freedom that we have is also determined by our current state. And then, of course, by environmental factors as well. The number of options that we have at any given time can be curtailed in lots of ways. And when it comes to things like addiction, then you really, really are curtailed. I mean, your capacity for rational conscious control really is inhibited by this overwhelming drive that's feeding into these decision-making processes and just pushing, pushing, pushing towards getting that, absolutely prioritizing that one goal over everything else, even if there's harmful outcomes and, you outcomes and changing the way that you

weigh reward and punishment and all those kinds of things. So I think the biology of free will, once we get past this sort of philosophical, do we have it or not, which to me is just a kind of red herring. It's clearly we do have the capacity for it. Then we get into more interesting discussions about, well, how does it vary? What are the things that can impinge on it or inhibit it? I'm Jason Alexander. And I'm Peter Tilden. And together on the Really No Really podcast, our mission is to get the true answers to life's baffling questions like... Why they refuse to make the bathroom door go all the way to the floor.

We got the answer. Will space junk block your cell signal? The astronaut who almost drowned during a spacewalk gives us the answer. We talk with the scientist who figured out if your dog truly loves you. And the one bringing back the woolly mammoth. Plus, does Tom Cruise really do his own stunts? His stuntman reveals the answer and you never know who's going to drop by mr brian cranson is with us how are you hello

my friend wayne knight about jurassic park wayne knight welcome to really no really sir bless you all hello newman and you never know when howie mandel might just stop by to talk about judging really that's the opening really no really yeah really no really go to talk about judging. Really? That's the opening? Really, no really. Yeah, really. No really. Go to reallynoreally.com. And register to win $500, a guest spot on our podcast, or a limited edition signed Jason Bobblehead. It's called Really, No Really, and you can find it on the iHeartRadio app, on Apple Podcasts, or wherever you get your podcasts. Addiction is one of those, I think it just is a very easy to understand. And when I say understand, sort of, I mean, visualize what we're talking about. Addiction is tremendously difficult to

understand as a overall phenomenon. But we can see, you know, that an addict is clearly being driven by something, you know. And so it's so interesting, because what I loved about reading your one book and your proposal for the other book, which I can't wait till it comes out because I love the way you arrive at we do have free will. There's so much of that was so fascinating. We just don't have time for. But one side, one extreme says, well, just choose not to use the drug, right? Just choose not to do it. And there's some truth in that there is ultimately a choice being made. Right. I'm choosing. Yeah. The flip side says, I'm an addict. I'm out of control. I can't do anything about it. And the truth is somewhere in between. And as somebody who has been around people who have addictions most of my adult life and have had them a couple times myself, I'm I'm so fascinated in what are the levers that are actually at work there? You know, like if I could have an answer to one question, well, actually, I'm not going to say that.

There's a thousand questions I want the answer to. But one that would be up high on the list would be why do some people recover and others don't? I don't understand it, you know, because I've watched people I care about deeply die, you know, from the same disease that I have recovered from and just don't understand it. But getting some insight into what some of those levers are, I think is really interesting. Yeah. And let me preface this by saying I'm not an expert in addiction biology, but I have some familiarity with it.

But I think one of the key things to keep in mind is not to put all of the emphasis on the individual. Because of course, there's the social context and the environment that's so, so crucial and maybe absolutely a determining factor in whether somebody does recover or remains addicted or worse. So I think that's the first thing is to say, even if there are genetic and neurobiological aspects to this, it's important not to say, well, that's where the explanation, the complete explanation is. Now, having said that, there are some differences between people and there is a genetics of addiction, right? You can study the genetics of that.

So a tendency towards addiction, actually, it's sort of a general tendency for any alcohol or tobacco or opiates or other sorts of drugs. There does seem to be a general underlying factor that makes some people more likely to develop addictions than others. Now, that's given that they're exposed, you know, that the opportunities are there to have these drugs and whatever other social factors are in there. So all of that is sort of averaged out, if you will. And then you can see there's some genetic differences at work. And, you know, some of them are really very specific. They affect the genes say for metabolizing alcohol so there are people this is a trait that's common in east asia in japan in particular

people who can't metabolize alcohol well it builds up as a an aldehyde that it makes them feel really sick and it's actually protective that variant is protective against developing alcoholism because you feel so bad when you drink alcohol that those people just tend not to. So there's a few sort of specific genetic variants like that that affect the proteins or the enzymes that actually metabolize the drugs or the receptors that sit in the neurons that actually, like opioid receptors or nicotine receptors and so on. the neurons that actually, you know, like opioid receptors or nicotine receptors and so on. But then there's also a really broad kind of what they call polygenic effect, which just means loads and loads of genes are involved, which seems to feed into this general addictiveness personality trait, if you will. The biology there is just really not known. It's probably pretty generic and kind of complicated, and I'm sure it won't come down to, you know, we could broadly look at addiction, you know, we're seeing two broad types of it. One is addiction to

substances, right? And then the other is addiction to behaviors, gambling or video games or shopping, right? And as you were talking, I was thinking, I wonder, you know, is that genetic predisposition lead to both of those equally or one versus the other? And I think, as you said, it's kind of complicated, but any thoughts on that? So there was an interesting paper just came out this week, actually, looking at this sort of general addiction factor, but it was substance addiction. I don't know whether the genetics or the neurobiology has in any way distinguished something like a gambling addiction, the tendency towards that, or like you said, the addictions to shopping or Instagram or Twitter or any of these other things

that are just behaviors that we develop. My guess is that all of those things will have an input from lots of different personality and character traits. You know, how sensitive we are to rewards, how willing we are to take risks, how impulsive we are, how conscientious we are about planning, you know, over longer term, prioritizing longer term over short term gratification. All of those things will feed in and probably in different profiles, in different ways and different people. So I think, I mean, the upshot is there probably won't be any simple kind of linear relationships between genes and those behaviors.

Right. And the data between the role of adverse childhood experiences on, you know, future addiction risk seems pretty clear also. You know, one of the things I think a lot about is, and we kind of keep circling it, but I do work with coaching clients and a variety of different things, is this idea of tendencies versus predispositions. Like I'll have people come to me and say, I'm the kind of person who X, right? And while there is value in recognizing your tendencies, there's also value in recognizing the ability to go beyond those. Yes. Yeah, absolutely. And I think,

you know, it's one of the interesting things. So some people would say in talking about, again, about human free will, that we just have these traits, our brain is just wired a certain way. And they would even say that, you know, we do things for reasons that are unknown to us and unknowable. We can't know why we do things. And also they'll say that, you know, my brain is wired just to do these causes that I had nothing to do with. So first of all, that's wrong, I think. You know, as we talked about in terms of character development, we as agents play an active part in that throughout our lives. And secondly, the idea that our reasons are just opaque to us, that we can't know them, is also just clearly wrong. I mean, those huge parts of our brains

are devoted to reasoning about reasons, to thinking about our own thoughts, and we can express our motivations to other people. So it's very clear that we do have access to a lot of our motivations and reasons. Now, it may be effortful. We may be wrong sometimes, but we're not wrong all the time. We're actually really good at that. And in fact, we're really good at understanding other people's motivations. That's what a lot of social cognition is all about. We're really hyper-specialized as a hyper-social species for precisely that kind of cognition, reasoning about reasons. And so what I think that gives is access, understanding those things in the first place,

knowing that you have this kind of trait is super useful. So knowing that you're, say, a procrastinator is really, really helpful if you can then actively put in place behavioral aids, if you will, that you know you're not going to do this task next week. You know, you're going to put it off and do something else instead of it. So you make yourself put something in your calendar. So you absolutely have to do it. And, you know, you develop the discipline to do that if you can. I mean, I'm terrible at that, but I try. Clearly not too terrible because you're fairly successful. Clearly not too terrible because you're fairly successful. Well, yeah, you'd be surprised.

But I think all of us can try to do that. And for me, the key thing is in recognizing I'm not going to change my tendency to procrastinate. Yes. But I can put in place behaviors that allow me to adapt to that so that it doesn't drive me and have negative consequences in my life, right? And that, I think, is the key thing. So if we're thinking about, you know, kind of self-help and personal development, pushing against yourself or thinking that you can change those underlying predispositions, to me, that's a futile exercise and it's only going to lead to frustration and a kind of

a cycle of bad outcomes. Whereas recognizing what they are and recognizing how they impact on your life and then saying, well, I can prevent that impact by doing A, B, and C, to me, that's a much more positive and much more practical and effective way to approach things. I love what you said there. And one way of thinking about that, again, you know, making everything about me, which is just for illustrative purposes, I think that I have an underlying, well, I know I have an underlying tendency, which is if I take a substance, I'm probably going to want to take it all the time.

I don't think that's going to change. The times I've thought it would change, I was wrong. And I've learned that through hard experience. So there are things that I can do that make that far less likely to be a problem. Or to use another example, I have a terrible memory. It is appallingly bad, right? And I think that's one of those things that you would say is, you know, there's some genetic basis to some of that. So, okay, I've got a bunch of systems in place that just mean I don't have to rely on my memory. Other people who've got a good memory

might be able to. I just learned, like, it's not going to work that way. So I think, you know, knowing our tendencies and then devising strategies. And I love what you said earlier about addiction. I didn't get a chance to comment on it, which is the environment and the support that's around us. Those things are so, so critical. Absolutely. You know, when I look at why did I get sober and other people didn't at the same time as

me, some of that I look at and I go, it was the support systems that I had. It was my socioeconomic class. I mean, there were supports that I had under me that a lot of other people simply did not have. Yeah. Yeah. And I think, as I said, I don't have a lot of professional expertise there, but certainly from my general understanding, I think that that's exactly right, that those sorts of social supports are key. You know, in terms of knowing that you have a tendency, that one has a tendency, a tendency towards wanting to take a drug if you take it, you know, wanting to take it again, then, you know, the steps that you can take is make sure that you're not in the situation where

those things are about, right? Yeah. You know, so you're preempting, you know, you know that you're going to give in to temptation if it's there. I don't mean you in particular. And so you're just taking preempting. You know that you're going to give in to temptation if it's there. I don't mean you in particular. And so you're just taking preemptive steps ahead of time to make sure you're not in the situation where you're exposed to that kind of temptation or the opportunity. So yeah, I think those aspects are things that people can control in principle, at least.

In practice, some people may be able to control them better than others for reasons of their own biology or for reasons of sociology and the environmental context and the amount of freedom that they have to create their own environments themselves. Yep. There's a line that you wrote that I really love. And this sort of summarizes, I think, a lot of what we're saying in a pretty short way, which is the slate is most definitely not blank, right? We're not blank slates. That's what you're saying. However, you say slates don't have to be blank to be written on. And I think that summarizes it really well. Like, yeah, of course we're not a blank slate and the slate can still be written on. Yeah. Thanks for saying that. Cause that to me does sum it up. And like you said,

it's a middle ground, which I hope is the realistic position, you know, that the two extreme positions of either complete freedom or total determinism are both false. And there's a much more nuanced, interactive kind of story to be told. And it's a story that we're telling ourselves, right? I mean, we're very much the authors of our own stories in an ongoing way. We start with some sort of predispositions and so on, but we become ourselves through our lifetimes. We go on becoming ourselves in ways that we have a large input to as well. In your latest book, you're talking a little bit about why you think we have free will.

And you say that the nervous system allows multiple signals to be simultaneously parsed and processed. Multiple, perhaps conflicting aims must be weighed against each other and an action selected. And that made me think because I was just reading some paper a couple weeks ago from an evolutionary psychologist who said that something similar to that they think that's what emotions are. Emotions job is to help us sort out when some of these multiple subsystems arrive at a draw, so to speak, right? Like one subsystem says, do this, the other subsystem says, no, I don't think so. And another one's like, wait a minute, you know, that emotions then arise as a way of deciding among those. As I read that line from you, I was kind of curious if you've heard that theory and does it make sense to you?

Yeah, absolutely. So a way to think about this is think of the function of the brain. It's not for thinking. We use it for thinking, but it didn't evolve for thinking. It evolved for control, right? It evolved for controlling us in a way that allows us to persist. And actually, in the simplest sense, parts of our brain that control our physiology are rebalancing. When our internal physiology goes a little out of whack, they release hormones. They say, hey, you need to do this, you need to do that. And some of the ways that we ensure we keep persisting are behavioral. So behavior is part of this control process. And it's obviously goal directed and the overarching goal is to keep us alive and in an evolutionary sense to, you know, keep us reproducing and so on. So if you think

about that as a control system, then within that, what you're going to want to have is some control signals that can specify certain drives. And I think the emotions exactly convey that kind of information. And so some of them are really powerful ones, like fear and pain, for example, which can actually just say, you know, ignore everything else. Stop ruminating about what decision to make here. Run. That's just run. That's it. So it's just like the signal is don't do anything else. I'm taking over. You're running. That's it. And then, you know, other ones, the sort of physiological signals like hunger and thirst, those are very much control signals as well. And what they do, I think, is prioritize.

So they upweight some of these possible actions because they upweight the drive that they're associated with versus all the others. So if you're very hungry, you'll be inclined to go and get something to eat. But for example, say you're an antelope approaching a watering hole and you're worried there's a lion around. Well, then maybe your hunger will win. Maybe your fear will win. And so these are balancing signals. And so in some way, they're these internal control signals that basically are correlates of the weight of different drives that we have. So it's a sort of a monitoring our internal states as well as what's out in the world

and saying, you know what, we need to prioritize this over that. And then the sort of, you know, the conscious control can kick in if we're choosing to exercise it and we have that capacity in the moment. And of course, you know, sometimes we do and sometimes we don't and and again some people are more driven by the short-term emotions that they have yeah again like children right i mean children are very driven by the short-term emotions that they have but as we get older and mature and we develop the skills of cognitive control we become better at just kind of surveying those emotions and using them as one input in our decision-making rather than letting a single emotion drive, you know, an action selection. Excellent. Well, Kevin, thank you so much. I've loved this conversation. I loved

the book and Nate, I loved the work you're doing on the upcoming book. I can't wait to see it. And thank you so much for coming on. Thanks a million. It was really a pleasure and a super interesting conversation, Eric. Thanks. If what you just heard was helpful to you, please consider making a monthly donation to support the One You Feed podcast. When you join our membership community with this monthly pledge, you get lots of exclusive members-only benefits. It's our way of saying thank you for your support. Now, we are so grateful for the members of our community. We wouldn't be able to do what we do without their support, and we don't take a single dollar for granted. To learn more, make a donation at any level, and become a member of the One You Feed community, go to oneyoufeed.net slash join.

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