Free will is an illusion. Here’s why

Hello and welcome to Instant Genius, the bike size masterclass in podcast form. Every Monday and Friday you'll hear from world leading scientists and experts, talking about the most fascinating ideas in science and technology today. I'm Tom Howard, trends editor at BBC Science Focus. Free will, as defined by the encyclopedia Britannica, is the supposed power or capacity of humans to make decisions or perform actions independently of any prior event or state of the universe. In a previous episode, neuroscientist Kevin Mitchell argued that human evolution has equipped us with the capacity for genuine free will. Go and check it out if you haven't listened to it already. Now though, we're turning the spotlight on the opposing view. In his latest book, "Determined, Life Without Free Will", we're now neuroscientist and recipient of the prestigious MacArthur Genius Grant, Robert Sapolsky, challenges the notion of free will, presenting a compelling case that our actions are largely determined by biological, environmental and chance factors. In this episode, Sapolsky gets into the reasoning behind his controversial conclusions, but he also looks beyond just a lack of free will, exploring how this realization might necessitate some fundamental changes to our society. And you know what? Even without the ability to truly choose, he still contends that life can hold real meaning. Robert Sapolsky, thank you very much for coming on Instant Genius today. Well, thanks for having me on. So to kick things off, we'll start with the real basics. Could you explain what we mean by free will when we're talking about it? Oh, making that not basic, you'll get at least two or three opinions out of every person you ask about this. But I think it's most helpful to start off with how most people define free will and how that gets them into trouble and to believing that it actually exists. Which is, you find yourself in some circumstance, you got to make a decision. Do I pick up this object with my left hand or my right hand? Do I pull the trigger and kill this person or let them live, you know, decisions like that, where you form an intent about it and then you do what you intend to do. And you know that you intend it to do whichever thing you do when you pull the trigger, you know you intend to do that. You're reasonably aware of what the consequences are going to be. And most importantly, you know, you don't have to do it. You've got an alternative. You could pick something up with your other hand. You can refuse to pull the trigger. You can do otherwise. And for most people having intent there and acting on it and knowing you could have done otherwise, that's a necessary and sufficient to decide that free will just happened. And at least in the court system in the US, that's pretty much necessary and sufficient to then hold somebody called for what they've done. And where I come in is pulling my hair out with apoplexy and that doing that misses everything that's important about this, which is asking this key question, how did you turn out to be the sort of person who attend to do that in that moment? How did you turn out to be what you turned out as in this instant there? And what that does is make questions, oh, did you pull the trigger or not? That's like asking about a book with it. You've only read the final sentence of it. You've missed everything that has gone on that has made you who you were and what sort of intent you would form. And all of that that's gone into that. You had no control over it. So before we dig into the real crux of why it is that you think that free will is an illusion. Did you possibly steal man the opposing argument? Why is it that scientists and thinkers believe that we do have free will, not just from a, because I feel like I have free will perspective, but from sort of their scientific argument on it? Well, sort of focusing on the philosophers and I need to trot this out because writing the stamp book forced me to actually read an agonizing amount of philosophers and looking at contemporary ones who were known as compatibleists. These are people who were willing to say there's a material world, there's atoms out there were made of cells. Yet somehow, somehow that's compatible with us having freedom in our choices that we can be who we are, that we could be uncaused causes. And I'm not trying to sound snarky and pejorative here, but when you look closely at every compatible ist argument as to how you can have free will in a world in which it's made of, we understand this 21st century universe to function something slipped in terms of the logic there. Every single model that's put up does not hold up to close examination because none of them are ever able to show how you can do your next behavior completely independent of your biological and environmental history. So to take an example then, could you walk me through how it was that I decided what to wear today? Why did I pick a gray sweatshirt instead of a red one for example? Okay, so we started that critical realm of our intent in acting upon. I see we have matching gray sweatshirts. Okay, so when you ask something like that, people who are thinking about free will in this compatibleist kind of way are usually satisfied to ask, so what went on when you looked in your drawer there and you had three sweatshirts to pick from and what did you think at that moment then you decided to get the one that you did? No, that's once again skipping 99% of what's going on. How did it turn out that you had this job that you needed to put a sweatshirt on for? How did it turn out that you've been successful enough at it that you could afford more than one sweatshirt that you could have multiple sweatshirts to choose from? How did it turn out that you were educated enough that you can like care about some person's stupid book? How did it turn out? How did you become this sort of person? How did you not wind up somebody with sufficient problems with the functioning of your frontal cortex that you've already gotten fired because you keep doing impulsive things on the air? How did you pick the right family to be born into, sarcastically saying that in terms of what your early environment had to do with the formation of your frontal cortex, et cetera et cetera. How do you wind up being you in this moment? Because if you ask it merely at the level of why did I pick this sweatshirt instead of that one, that's got like a false sense of free will over it. How did you wind up in this moment? There's no free will there. So it's essentially the fact that every current state that we are in has been preeminated by the current state before that, which goes back and back in the system of causing effects down to evolution, our genes, the environment we're in. Absolutely. And it comes down to the fact that there's nothing other than that when trying to make sense of how did you get here. All we are is the biology over which we had no control and its interactions with environment over which we had no control. There's nothing else there. Then what some thinkers and scientists might say at that point is that we're obviously hugely influenced by our genetic makeup and the environment that we're in and the history of our lives and of the universe, but that we're still at that point able to take that influence and make a decision, particularly in the way that we can reason about the decisions that we're going to make and we can change our mind. Does your argument not fall flat there? No, because the question then becomes, how did you have the values to reason in the particular way that you did? Presumably, what counts as the most logical, expeditious, morally upright, aesthetically acceptable, whatever version of decision you've made that you have reasoned your way to, how did you turn it to the sort of person where you would value that as the most compelling reason? How did you turn it to somebody who would even value reasoning and reflection and all of that? Yes, all the way back. Another kind of strand of the argument for having free will is the fact that we kind of seem to have these involuntary actions like removing our hand from the surface that's hot versus what feels like a voluntary action. Under your line of thinking are those almost the same kind of behaviors going on? How can we differentiate them? They're the same mechanistically, but the level of complexity involved. When you put your hand down on something hot and you move your hand back instantly, there Here's a biological phenomenon that has just gone on. Which among other things is sensitive to interactions with environment that you've had your entire life How fast you will detect the heat how painful it is whether that sort of thing and you pull all that off with about three and a half neurons in your spinal cord sit around and decide are you going to be this type of philosopher for your life or that type and It's the exact same circuitry. It's just vastly more complicated, but it's made of the same stuff and When you look at how like some C slug Learned to act differently and a bunch of Nobel prizes and handed out for that of like breaking that down to the molecular level of like you take some C slug and Normally you poke its gill that it breathes with the C slug's breath It's got some sort of gill you poke it there and it retracts it protectively and it could learn that if you keep Bopping it on the head with a neutral stimulus it will learn when you pop it on that to withdraw that gill It learned it learned and then you spend 50 years being like some of the greatest neuroscientists in the last century figuring out how did that work and It turns out not only are it the same conceptual things going on when you learn to Hate this out group or learn to be a neilist or learn to like horrible music of the genre whatever it's not only the same general motif You're using the exact same molecules. It's the same circuitry You could take some of the key genes that you activate when you're learning how to be a Compatibleist philosopher and you could genetically engineer things and stick it into a C slug and it will learn about that whole simple circuit exactly the way it did before All it is is biological circuitry that can be changed dramatically by environment Absolutely where most of the interesting stuff happens, but nonetheless when you look at how it works That's all there is there's no other place in there where you could posit that every now and then a Neuron or a brain region or a brain or a person has just done something completely independent of everything that came before in terms of biology and interactions with environment One of the other Arguments that crops up a lot in this space is to do with the sort of physics of it people talk a lot about how In quantum physics as an element of randomness that even if you can feel like you can determine how a Neuron white work at the atomic level It's impossible to determine anything Why is that a flawed argument in this space? Okay, this is where I scream an agony. Oh no quantum indeterminacy to the extent that I can understand any of that as this very very simple Minder neuroscientist instead of as a physicist Sounds like currently I don't know 70 80 percent of physicists believe in what's called the Copenhagen interpretation of quantum indeterminacy Which is to say that when you get down to the itty bitty level Way, way subatomic stuff really happens without any prior cause and People still don't understand that it works, but that seems to be the case and the second that became Moderately clear people have been running with the idea that you build free will on This quantum indeterminacy this gets you around the notion that this is a deterministic world that made you do what you did just now and The quantum argument falls apart for three reasons first off because the level at which this stuff is occurring is so Many dozens of orders of magnitude below the level of what would significantly influence the functioning of Molecule and one neuron the best estimates by people who really think about this is you'd have to scale up something like 20 orders of magnitude to have an effect there It simply doesn't go that high because what would happen is the unlikely hood of all of those subatomic particles all spinning the exact same way at the same time so that it could go up 20 orders of magnitude and Make this neuron hiccup at this point is Beyond the likelihood of anything in the universe. So that's the first problem The second one is supposed to actually does bubble up that far instead of getting lost in the biological noise What you've just come up with is a means for generating random behavior This is where randomness comes from and if you believe that the randomness of subatomic particles Sort of the basis of your moral compass and the decisions you've made things like that This is a mechanism for randomness Third problem is the people who really get fancy with their like highwire act at that point is that somehow Somehow they speculate we have the means to harness the randomness in order to then reach down from the macro level that makes us us But they're consciousness and get those subatomic particles to all spin in the way that Produces an outcome that was driven by your supposed free will and it doesn't work that way the macro level can't reach down And somehow pull intent out of the randomness There's no mechanism for it. So the quantum stuff. There's a remarkable number of very solid thinkers who have focused on this in the realm of understanding behavior There's a remarkable number of cracks and snake oil salesmen who have done the same with ridiculous best sellers and think that Quantum in determinacy is not where your free will is coming from it can't work that way Extrapolating your argument if we hypothetically were able then to have enough information about someone's genetics that upbringing the environment they find themselves in In theory would you be able to predict How they would behave in any given scenario? No, and the fact that you can't does nothing to the argument that there's no free will is soon as somebody sort of you make the Arnie minutes in deterministic world. There's no free will and what just happened was a result of what just happened before before you know what they're saying Oh in other words the entire future was already set two seconds after the big bang and the answer is No, that would be a pre-deterministic mindset rather than the contemporary set of determinism Why is it impossible to predict what's going on? Because there are all sorts of things just sewn into the fabric of how the universe works Where unpredictability comes in at the level of Chaoticism at the level of non-linear systems that the level of non-aditivity at the level of emerged and complexity things of that sort Those are things where no degree of getting better at looking tiny or tiny or things with better and better resolution Can ever give you any predictive power because this is the butterfly effect This is the world in which like one minor event on one side produces this whole cascade that is Formally unpredictable. So the fact that all the interesting stuff in the universe runs with chaotic non-linear systems Means that right now in this moment There actually are multiple possible universes because unpredictable things are going to happen How does this fit with those no free will stuff once whatever Universe has thrown it to you in terms of the randomness and your behavior or outcome has occurred You could sit there and then look back and see Given that bit of randomness in the universe at that point had it we get here Oh because I turned out to be the sort of person who would do this and that circumstance and neurons that would respond in this way Because of all of this high level non-linear stuff the future is not already determined but How you will respond to that in deterministic future has already been determined by how you are the being who you are in this instant Do you think that the complexity of this explanation of how we behave is kind of what adds to People's belief that they have free will do you think that if it was simpler we perhaps realize your argument more readily? Oh Absolutely, but if you really frame it and if you Okay a mechaistic fact you stick this chemical called caffeine into somebody and Whether or not you put that into the drink they drank as your experimental subject is going to have a significant Influence on how fast they can like do pressured math problems or something like that You've just shown one tiny piece of where one lever is in the thing that constitutes the biological machineness of us and you pile on a hundred zillion of those examples and Where you see is there's no wiggle room in there for Getting around all of this business of how you got here what this brings us to is why nonetheless does it feel like You're making a decision some of the time we can recognize when there wasn't a decision you take a criminal decision defendant who's like done something appalling and when this guy was 10 years old he was in some horrible car accident which destroyed the frontal cortex of his brain and he has been an out of control machine ever since and most juries are capable of sitting and saying whoa okay here was the singular event that car accident and here's this massive like steel arc of causality that has gone from that event to why he's an out of control murderer here who can't regulate his behavior good I get it that makes sense all of that the trouble where people think they're seeing free will is when you look at the rest of us what's going on is much more likely is a hundred billion little spider webs of causality of stuff that went on before which worked to this moment and the two intellectual problems with that is we don't understand most of those spider webs at this point for like still lots of science but the hardest thing is to accept to understand that you put all those spider webs together and it's going to form a steel arc that is just as deterministic it's just hard to see where all of those came from and it's in that pool of cognitive challenge that people decide what they've seen instead is you got here without the spider webs yeah so essentially what you're saying is adding levers on top of each other doesn't change the fact that they're all just the same deterministic mechanistic levers and our intuitions fall apart at the point that like you've really got to put a lot of the little pieces you know know all about genetics and you're not going to be able to explain why there's no free will know all about hormones same thing know all about cultural influences know all about what your neurons did after breakfast this morning no single one of those is going to give you emphatic proof that we're just biological machines put all the pieces together and it's there not just because it's important to have all these multi-disciplinary views put them all together and they turn into one discipline if you're talking about the effects of genes on behavior you're talking about millions of years of the evolution of genes and you're also talking about your fetal environment that did regulation of those genes for your lifetime and you're also talking about which proteins those genes made in this part of your brain 20 minutes ago and when you put all those pieces together it forms that steel arc and that arc doesn't have a crack in it in which you could shoehorn this just happened independent of the history of what brought that person to that moment is just not there but it feels intuitively so hard to accept that you touched on sort of the legal system a minute ago there and I'd like to move on to what are some of the consequences of was not having free will it's quite a big part of your work so perhaps if we can start with looking at the legal system and then look more broadly at the rest of our lives generally good well the legal system is easy and that you have to completely totally flush it down it has to go entirely because it's predicated on this notion of free will if you really believe this stuff that we are nothing more or less than biology interacting with the environment that brought us to this moment it never is intellectually or morally acceptable to blame someone for anything and to punish them parentheses likewise to praise them and reward them and the discussion about what to do with the penal system is perfectly mirrored by what to do with meritocracies but okay at the penal end if you really truly believe that it never ever makes sense to view someone as deserving anything as having earned anything as a concept of justice being served as a concept of justice all it is is how do you protect society from this biological machine that turned out to be damaging in this context there this is the point where there's got to be free will because people are going to run them up water you could just have murderers running around in the streets and oh absolutely not you can construct a society in which damaging people you understand how they got damaged in a particular way and you apply what people in the business call a public health model you quarantine them not quarantine them in the sense of like putting them on a desert island you do the absolute minimum needed to protect society from the elements of their behavior that are damaging and you don't go any further and most importantly you don't preach to them about how they have a rotten soul and then you put some work into how do people turn out that way in the first place how does this type of damage damage people in this way oh my god that sounds so abstract we do this all the time your five-year-old kid is sneezing and you don't send them to school because the rule is please if you shy of us running nose keep them home so they don't get everybody else you can strain their behavior to protect society from their sneezing you just do that they stay at home you don't tell them you can't play with your toys because you've got a rotten soul that made you sneeze and Satan is up there in your sinuses and you don't preach to them about having a soul and having that have anything to do with their nose running and in a public health certain moral imperative you make sure people do research is to why running noses wind up happening and how we can prevent them and that's a quarantine model and we do those all the time without recognizing we have just decided there's no free will in the issue that sneezey kids can get everybody else sick and nonetheless without any responsibility or moral judgment being thrown into it we can protect society from your five-year-old sneezing and that's just a model for how all of this has to look and the flip side in terms of meritocracy just is you don't want to have murderers running around on the streets damaging people you don't want to have totally random person chosen on the street to take out somebody's brain tumor you need to protect society from that way and you need to generate a world in which without praise or reward or sense the just because you happen to be good at this or that intellectual thing you were intrinsically more morally worthwhile than other people you got to figure out nonetheless how to get people to work hard enough and study hard enough to turn into competent brain surgeons or plumbers or judges or poets or things like that it's the exact same problem flipped the other way and in a lot of ways that one is easier you can figure out how to get rid of free will and keep kids from sneezing and keep society safe from damaged people who are damaging that's one is just about constraint the flip side with meritocracies is how do you motivate people to like skip party after party while their roommate goes out and does that because they're studying to be the world's best scholar about you know angle or the world's best neuroanonymous to it had you motivate people to do the really hard work without them coming out the other end feeling as if they have earned a stance of greater moral worth because they worked hard out of the same biology that made a sea slug do whatever it did you can construct a world in which you protect society from damaging people and a far more complex challenge you can construct a world in which you can motivate people to do the hard work needed to gain expertise that is desperately needed so society is safe from incompetent people and you can do it without invulking any sort of smell of moral judgment I wonder if we have the sort of feeling that we have free will could it not be argued that it's good to play to that feeling for example using criminal punishment as a deterrent influences someone's decision making not in a free will kind of way but in a if you know that you could go to prison and it's not nice in prison that might influence your decision not to commit a crime oh absolutely that's mechanistic that's completely you can absolutely use punishment or reward in an instrumental sense you could do that if you're training a sea slug to change its behavior and it's the same thing for any biological organism that is responsive to stimuli yeah you can do that and sometimes punishment is good to be the most effective thing and sometimes telling somebody what a wonderful job they did and they must have studied so hard is the most effective thing for increasingly odds that they'll do that in the future or people watching them will say oh I want to get complimented by that it's great to use those in instrumental ways just don't slather a notion of moral worth on it one way or the other and recognize that it's often much easier and lazier to just say okay this is one of those circumstances where we need to pretend as if there is because when you really follow through sort of in a deep utilitarian level okay if I do this this is more likely to happen and that's more like the when When you look at that, most of the time when you work through all the likely consequences, it isn't going to make the world a better place. If every time somebody sneezed or Jay walked across the street, you executed them. That's certainly a way to deter people from like Jay walking or whatever, but you follow through the consequences of that and that one's not going to be a good picture in terms of a society that could do that. It's going to be society could do this as well and that as well. It's a slippery slope. All the fine to use those as instrumental tools to pretend as if this is a circumstance worthy of punishment or reward be really suspicious when you've made that decision because one of the temptations is it feels really good to reward certain types of people and it feels really good to punish righteously. It's an amazing neurobiology as to why we like to punish. It's rewarding and how that evolved. So be really suspicious when you think you've decided this is one of those settings where we need to decide there's free will and use punishment in an instrumental sense. Be suspicious how you got there and make sure you don't decide that anything resembling this nonsensical concept called justice has been served when you've done that. You've just figured out if you have some self-discipline and looking at your own motives that this is a good button to press in the circumstance on the biological machine instead of that button, nothing more than that. So one final question and in an attempt to try and not leave our listeners feeling downtrodden as though they're nothing more than meet puppets operating through this world. How do we extract meaning from a life without free will? How do you do it as well? This is the ultimate one. What do we do with serial murderers and what do we do with CEOs who get salaries that are 100 fold bigger than the workers? All of that. Yeah, once we solve all of that, there's the, what do you do with the fact that we're biological machines? I love my wife desperately and part of how that happened has to do with what sort of upbringing I had and what sort of cultural values for what sort of face I find attractive and what factory receptor genes I wound up with in my nose when I smell pheromones from her. It has this or that effect and you know everything in between the whole had it I get to this point and become that sort of person, but that doesn't take anything away from the feeling of love. And you could look at like a gazelle all year out in the savanna and some gazelle has just done the most amazing like leap agribatic thing in your jaw drops open that these animals are capable to you could have just spent the last 50 years being the world's expert on gazelle pelvis and know exactly the biomechanics of how that gazelle came to be able to do that. And that doesn't take away the slightest that it is still like damn amazing watching one of those things love still feels like love pain is still painful and we're this totally weird biological more organism that unlike all the other ones on the planet we could know that we are biological organisms and we could know that pain is painful and somebody else's pain is painful to them and all sorts of sort of changes in behavior that can flow from that and we can also get incredibly neowistically depressed out of the where do you find meaning out of that. And the only thing to fall back on is we're biological machines but nonetheless we can have machines that in the face of incredible sunsets can say it's all worth it. This is why we're here. Life is a gift. I feel grateful for this dropping your jaw even though all sorts of scientists can tell you why it turned our inch at that point instead of like green fluorescent during this amazing sunset there's a science to it and why your photoreceptors and why you're responsive to this type of natural beauty rather than that. All that that doesn't take away the fact that when we have moments where pain is painful and where we've turned out to be the sort of person where somebody else's pain is painful and you want to act a lesson at for them or moments where you feel just incredible gratitude that whoa this is how things turned out where machines you turned out to be able to be that way and we could understand it and we have the option of deciding gazelles don't look amazing anymore when they leap just because there's equations for like the folk room of their pelvis and their whatever the bone below that is called or it's still damn amazing. When they leap and it's still awful when somebody else is being put through pain when you have the power to stop it and that's still there the fact that there is structure underneath the surface doesn't rob the surface of what is capable of evoking than us. So that was Robert Sapolsky a professor of biology neurology and neurosurgery at Stanford University to discover more about the topics we've discussed check out his book Determined Life Without Free Well which is on sale now. Thanks for tuning into another episode of Instant Genius brought to you by the team behind BBC Science Focus magazine which you can find on sale now in supermarkets and news agents up and down the country. If you've enjoyed this episode make sure to subscribe by your preferred app and why not write us a review. You can of course always find us on sciencefocus.com (upbeat music)