What our brain chemistry says about free will

In his new book, Stanford professor Robert Sapolsky argues that free will is a myth.

There are many ways to think about the history of humanity. One of them is to say that we’ve gradually lifted ourselves out of ignorance as we’ve learned more about the natural world.

No one is burning witches anymore, thankfully, and no one seriously believes that demons are the cause of diseases; if there are exceptions to this, they are exceedingly rare. We can count that as progress.

But reflecting on all this should prompt an uncomfortable question: What do we believe now that might, in retrospect, look absurd to future humans?

Robert Sapolsky, a professor of biology and neurology at Stanford University, thinks belief in free will is a good candidate. He’s the author of a monumental new book called Determined: A Science of Life Without Free Will, which musters all the latest science to make the case against the existence of free will.

It’s a heavy lift to be sure. We all have the subjective experience of feeling like we’re the authors of our thoughts and actions, but Sapolsky argues we know enough about the brain to say it isn’t true, and that we need to accept it. If he’s right, the moral and legal implications would be enormous. The way we think about success and failure, as well as blame and punishment, would have to change.

So I invited Sapolsky onto The Gray Area to talk about it. Below is an excerpt of our conversation, edited for length and clarity. As always, there’s much more in the full podcast, so listen and follow The Gray Area on Apple Podcasts, Google Podcasts, Spotify, Stitcher, or wherever you find podcasts. New episodes drop every Monday.

Sean Illing

How do you define “free will”?

Robert Sapolsky

Maybe the best place to start is to point out how most people define it, because that immediately starts getting you into trouble, and it’s probably best displayed in a courtroom. You have some defendant sitting at the table and everybody agrees the guy did it. And now there are three questions that strike everyone intuitively as covering the entire universe of free will.

First off, did the guy intend to do what he did? Did he understand what the outcome was likely to be? And did he realize he didn’t have to do it, that there were alternatives available? And if the answer is yes to all of those, the guy’s responsible. He knew what he was doing. He exercised free will.

And this is what gives me polite apoplexy throughout this book, because in my view, what you’re doing is you’ve got a movie reviewer and they’ve got to write a review of a movie and all they’re allowed to see is the last three minutes of the movie. Why is that? Because amid those [questions] — did he intend, did he know he had alternatives, all of that — it’s not asking the only question that now has to be asked, which is, “How did he wind up being the sort of person who would intend to do that? Where did that intent come from?” And that’s where free will sort of withers on the vine.

Sean Illing

So let’s put it this way: If I rewound the movie of my life and I held every little thing constant, right down to the breakfast I had every morning, down to the amount of sleep I got every night, could I have done otherwise at any moment in my life or do you believe everything would’ve unfolded exactly as it did the first time around?

Robert Sapolsky

In theory, yes. This was an idea put forward a couple of centuries ago. This notion that you could rerun the tape with everything held constant and you’d always get the same exact outcome. In reality, it doesn’t work that way because there’s randomness thrown in, Brownian motion, so that you release a little bit more of this neurotransmitter rather than less, and collectively at 15 gazillion synapses, that winds up making a difference. And the basic chaoticism of systems means that tiny, tiny differences due to randomness get amplified, the famous butterfly effect. So in effect, this makes this thought experiment impossible to do. But if you could control for all the random little molecular hiccups going on, yeah, you’d get the same outcome if everything else in the universe was held constant also.

Sean Illing

Philosophers often make the case for some kind of compatibilism by arguing that the same inputs in different individuals don’t always produce identical outcomes. It’s more like the world and all these factors impose parameters on us, which does leave some room for agency. For you, is this just an attempt to redefine free will in order to salvage the concept?

Robert Sapolsky

Yeah, exactly. It’s trying to get a little bit of wiggle room by saying, “Okay, okay, some stuff about us is determined, but there’s a whole other domain where it isn’t.” And the version of that that is most seductive to people is they will admit that there’s stuff about us that we had no control over — how tall we are, what our memory span is like, if you’re a runner, whether the muscle fiber makeup in your thighs makes you a sprinter or a marathon runner — that’s all this biology stuff, and people are willing to admit that.

And where the free will then comes in is this abyss that people then fall into, which is saying, “Yeah, you have no control over your attributes, but what you do with them, that’s where you show your free will.” Do you show tenacity? Do you show backbone? Are you instead self-indulgent, do you squander away your gifts? And that’s this divide that people have in their heads and where you decide you can judge the character of someone based on what they do with what fate has handed them.

And the critical thing is how tall you are and what your neurons are connected up with is made of biology, and what you do with it, whether you show tenacity or you squander and everything in between, is made of the exact same sort of biology. That’s not an area where magically you’re free of that. We are just as much an outcome of determinism when looking at whether we can make use of our gifts or whether we can overcome our adversities.

Sean Illing

The use of the word “tenacity” there is revealing because this is the argument one hears constantly in these sorts of conversations. Someone will point to people who faced equivalent or near-equivalent challenges and life circumstances and note that some of them flourished in spite of those challenges and some of them didn’t, and this is supposed to be an argument in defense of the power of will and grit and that sort of thing.

Robert Sapolsky

I fail to resist this sort of argument all the time because it’s so damn inspirational. You’ve got some 7-foot-4 guy who’s in the NBA and nobody’s surprised. And then you get this guy Muggsy Bogues, who was 5-foot-3 and played in the NBA and he did that out of nothing but tenacity and gumption and Calvinist focus. It’s so hard not to be totally moved by that, at this display of willfulness, but there is no willfulness in the free will sense going on there.

Sean Illing

So what’s going on there?

Robert Sapolsky

You’ve got a part of the brain, it’s called the frontal cortex. We’ve got more of it than any other species. It’s the most recently evolved in us and it does exactly what puts you in the world of gumption or squandering your gifts. What the frontal cortex does is it makes you do the hard thing when that’s the right thing to do — self-control, discipline, impulse control, emotional regulation, all that sort of stuff. And what kind of frontal cortex you have is the outcome of everything that happened in your life beforehand.

Here’s one example that should have people outraged: socioeconomic status. By the time a kid is 5 years old, the socioeconomic status of the home they came from is already a significant predictor of how thick their frontal cortex is going to be, what its metabolic rate is, how well it works. By age 5 already, this is someone who neurobiologically — not because they don’t have a great soul, but neurobiologically — is already going to be lagging behind at things like impulse control and long-term planning. And people even know the nuts and bolts of how the stress of poverty turns into chemical signals that make the frontal cortex lag in development. And you look at that and there’s no room for magic dust in there. It’s just another part of the biological stuff that makes you up.

Sean Illing

Is there ever an intellectually coherent reason to hate another human being?

Robert Sapolsky

No.

Sean Illing

Under no circumstances?

Robert Sapolsky

Not in the slightest, under no circumstances, because if you really, really follow the logic of this out, hating somebody makes as little sense as hating an earthquake or hating a coronavirus or hating the fact that predators are predatory out on the savanna. Hate makes absolutely no sense.

All of that said, I know I’m going on here with these absolutes, I’ve been thinking this way for more than 50 years. I was an adolescent when I decided there’s no free will. I absolutely think this way. I’m completely intellectually at peace with the notion that there’s no free will at all. And I can act on those conclusions maybe 1 percent of the time because it’s hard. I get pissed off at people, or I am pleased and feel somehow like I earned it if somebody says, “Wow, nice shirt you’re wearing,” or something like that. I’m a person of my place and time and I recognize how hard this is because I fail over and over and over. So yeah, none of this is easy.

Sean Illing

I’ve heard these sorts of arguments against free will before, and no matter how much sense they make, I find it nearly impossible to behave as though I really believe it. I still can’t help but feel moral outrage at a child rapist just as I can’t help screaming at my dog every time she barks at the mail truck, even though it makes no sense. She’s just doing what she does. But this stuff is so hardwired into us, it’s very difficult to change how we respond to it or how we think about it.

Robert Sapolsky

Yeah, it seems unimaginably difficult until we reflect on something, which is that we’ve already done it time and time and time again. If you and I were exactly the people we are now and we were sitting around 500 years ago and there was a horrible lightning storm last night that destroyed all sorts of crops, it would’ve made total intuitive sense to us that we hope the authorities track down whichever witch caused that lightning storm. And we would’ve thought justice was served when the person was burned at the stake because it would’ve been inconceivable to us that there’s no such thing as witches and that’s not what caused lightning storms. But we changed and society changed. And now what was intuitively obvious then is intuitively ridiculous to us now. We’ve managed that one. Our society has done that over and over in all sorts of realms, and all we have to do is push against the things that seem intuitively obvious right now in terms of who deserves what.

Sean Illing

As you know, there are a lot of people who really believe that scrapping our belief in free will and moral responsibility would be very dangerous. To those sorts of objections, you say what?

Robert Sapolsky

I say that it would actually make things much better. I mean, the first thing people do when you try to do the “no free will” on them is they say, “Oh, does that mean nothing could change?” And you work your way through that, and then they say, “Oh, are you saying when somebody works really hard to overcome their adversity, there was no willfulness in there?” And you say, “Yeah, you can’t will yourself to have more willpower than you have because that’s how the science works.” And then they come around to saying, “Oh my God, people are just going to run amok because everyone will know they can’t be held responsible for anything.” And some research suggests that when you unconsciously prime people to believe less in free will, they start cheating on stuff afterward — that’s the worry.

And then you look more closely at a literature like that and instead of getting somebody where you have to psychologically manipulate them into feeling less belief in free will, get somebody in your study who shows up who already doesn’t believe in free will, who hasn’t believed in it in years and years. And you look at someone like that and they are exactly as ethical in their behavior as someone who says, “We need to be held responsible for every one of our actions.”

It’s the exact parallel of when people look at atheists and say they’re going to be totally immoral because there’s no God to answer to. And a massive amount of research has shown when you look at people who are very, very stridently and emotionally invested in atheism, they are exactly as ethical as people who have extremely strong beliefs in religiosity and moral imperatives coming from that. What’s that about? These are totally opposite conclusions about the world.

They’re the same in a critical way, which is whatever outcome you came to, you thought hard about it. You had to think about where good and evil come from. You had to think about what’s the source of meaning in life. You had to think about what sort of person you want to be and what to make of your failings. You’ve thought long and hard about it. And if you’ve done enough of that, it really doesn’t matter if your conclusion is human goodness comes from us or human goodness comes from God, you’re going to be a better person. And this is what the studies show.

Sean Illing

The argument that we would all be cannibals if we didn’t believe in God has always been extremely stupid and offensive, but you can still believe in something like free will and moral responsibility even if you’re an atheist. I guess on some deep level I still think that our beliefs can act as a kind of motive force. Believing that we have control over our actions, believing that we’re morally responsible might lead us to actually behave more responsibly. And for the same reasons, believing that we don’t have any control might lead us to act more nihilistically. But I might be completely wrong about all that.

Robert Sapolsky

Yeah, people can be raised believing you should be held responsible for your actions and you’ve got a crummy soul if you do something awful, and we don’t have a very good track record in terms of a society that’s overwhelmingly theistic. I would argue that there’s absolutely no reason to think that people are all going to run amok.

But nonetheless, it’s true, there’s still going to be some people who run amok, and this is where people really panic with the notion that there’s no free will. “Wait, are you saying that you’re just going to let murderers run around on the streets because they’re not responsible for their actions? What kind of madhouse will this be?” And the answer is, of course you don’t do that. If you’ve got someone who’s dangerous, you protect people from them, but you do it in a very different way than we do now because the current version is built on the notion of retribution and responsibility and free will.

To hear the rest of the conversation, click here, and be sure to follow The Gray Area on Apple Podcasts, Google Podcasts, Spotify, Stitcher, or wherever you listen to podcasts.