Determined: A Science of Life without Free Will

by Robert M. Sapolsky

The answer is that the behavior happened because something that preceded it caused it to happen. And why did that prior circumstance occur? Because something that preceded it caused it to happen. It’s antecedent causes all the way down, not a floating turtle or causeless cause to be found.

To reiterate, when you behave in a particular way, which is to say when your brain has generated a particular behavior, it is because of the determinism that came just before, which was caused by the determinism just before that, and before that, all the way down.

Why did that behavior occur? Because of biological and environmental interactions, all the way down.[*] As a central point of this book, those are all variables that you had little or no control over. You cannot decide all the sensory stimuli in your environment, your hormone levels this morning, whether something traumatic happened to you in the past, the socioeconomic status of your parents, your fetal environment, your genes, whether your ancestors were farmers or herders. Let me state this most broadly, probably at this point too broadly for most readers: we are nothing more or less than the cumulative biological and environmental luck, over which we had no control, that has brought us to any moment. You’re going to be able to recite this sentence in your irritated sleep by the time we’re done.

we’re heading into very different terrain, one that I suspect most readers will not agree with, which is deciding that we have no free will at all. Here would be some of the logical implications of that being the case: That there can be no such thing as blame, and that punishment as retribution is indefensible—sure, keep dangerous people from damaging others, but do so as straightforwardly and nonjudgmentally as keeping a car with faulty brakes off the road.

it can be okay to praise someone or express gratitude toward them as an instrumental intervention, to make it likely that they will repeat that behavior in the future, or as an inspiration to others, but never because they deserve it.

no one has earned or is entitled to being treated better or worse than anyone else. And that it makes as little sense to hate someone as to hate a tornado because it supposedly decided to level your house, or to love a lilac because it supposedly decided to make a wonderful fragrance. That’s what it means to conclude that there is no free will. This is what I’ve concluded, for a long, long time. And even I think that taking that seriously sounds absolutely nutty.

People’s beliefs and values, their behavior, their answers to survey questions, their actions as study subjects in the nascent field of “experimental philosophy,” show that people believe in free will when it matters—philosophers (about 90 percent), lawyers, judges, jurors, educators, parents, and candlestick makers. As well as scientists, even biologists, even many neurobiologists, when push comes to shove.

research that we’ll look at in a later chapter suggests that other primates even believe that there is free will.[2]

This book has two goals. The first is to convince you that there is no free will,[*] or at least that there is much less free will than generally assumed when it really matters.

faulty logic, such as concluding that if it’s not possible to ever tell what caused X, maybe nothing caused it. Sometimes the mistakes reflect unawareness or misinterpretation of the science underlying behavior. Most interestingly, I sense that mistakes arise for emotional reasons that reflect that there being no free will is pretty damn unsettling; we’ll consider this at the end of the book. So one of my two goals is to explain why I think all these folks are wrong, and how life would improve if people stopped thinking like them.[3]

Yeah, no single result or scientific discipline can do that. But—and this is the incredibly important point—put all the scientific results together, from all the relevant scientific disciplines, and there’s no room for free will.[*]

the first half of the book’s point is to rely on this biological framework in rejecting free will.

As I said, even I think it’s crazy to take seriously all the implications of there being no free will. And despite that, the goal of the second half of the book is to do precisely that, both individually and societally.

The book’s intentionally ambiguous title reflects these two halves—it is both about the science of why there is no free will and the science of how we might best live once we accept that.

Determined: A Science of Life Without Free Will.

Styles of Views: Whom I Will Be Disagreeing With

The world is deterministic and there’s no free will.

The world is deterministic and there is free will.

This is roughly 90 percent of philosophers and legal scholars, and the book will most often be taking on these “compatibilists.”

The world is not deterministic; there’s no free will. This is an oddball view that everything important in the world runs on randomness, a supposed basis of free will. We’ll get to this in chapters 9 and 10.

The world is not deterministic; there is free will. These are folks who believe, like I do, that a deterministic world is not compatible with free will—however, no problem, the world isn’t deterministic in their view, opening a door for free-will belief. These “libertarian incomp...

There’s free will, and people should be held morally responsible. This is probably the most common stance out there.

compatibilist view that while the world is deterministic, there is still free will, and thus holding people morally responsible for their actions is just. This version of compatibilism has produced numerous papers by philosophers and legal scholars concerning the relevance of neuroscience to free will. After reading lots of them, I’ve concluded that they usually boil down to three sentences: Wow, there’ve been all these cool advances in neuroscience, all reinforcing the conclusion that ours is a deterministic world. Some of those neuroscience findings challenge our notions of agency, moral responsibility, and deservedness so deeply that one must conclude that there is no free will. Nah, it still exists.

Show me a neuron (or brain) whose generation of a behavior is independent of the sum of its biological past, and for the purposes of this book, you’ve demonstrated free will. The point of the first half of this book is to establish that this can’t be shown.

Laplace provided the canonical claim for all of determinism: If you had a superhuman who knew the location of every particle in the universe at this moment, they’d be able to accurately predict every moment in the future.

. . . White male Pierre Simon Laplace, the eighteenth-/nineteenth-century French polymath. . .

Science since Laplace’s time shows that he wasn’t completely right

Contemporary views of determinism have to incorporate the fact that certain types of predictability turn out to be impossible (the subject of chapters 5 and 6) and certain aspects of the universe are actually nondeterministic (chapters 9 and 10).

We’re also going to wire up your hand with recording electrodes to detect precisely when you start the pushing; meanwhile, the EEG will detect when neurons that command those muscles to push the button start to activate. And this is what we find out: those neurons had already activated before you thought you were first freely choosing to start pushing the button.

you get the same answer—the neurons responsible for whichever hand pushes the button activate before you consciously formed your choice.

we’ve bought a neuroimaging system and will do functional magnetic resonance imaging (fMRI) of your brain while you do the task—this will tell us about activity in each individual brain region at the same time. The results show clearly, once again, that particular regions have “decided” which button to push before you believe you consciously and freely chose. Up to ten seconds before, in fact.

I think that at the end of the day, these studies are irrelevant.

“Libet-style studies.”[*],[2]

people reported that they decided to push the button about two hundred milliseconds—two tenths of a second—before their finger started moving.

the evidence that the brain had committed to pushing the button, occurred about three hundred milliseconds before people believed they had decided to push the button. That sense of freely choosing is just a post hoc illusion, a false sense of agency. This is the observation that started it all.

in Libet 2.0, the work of John-Dylan Haynes and colleagues at Humboldt University in Germany. It was twenty-five years later, with fMRIs available; everything else was the same. Once again, people’s sense of conscious choice came about two hundred milliseconds before the muscles started moving. Most important, the study replicated the conclusion from Libet, fleshing it out further.[*] With fMRI, Haynes was able to spot the which-button decision even farther up in the brain’s chain of command, in the prefrontal cortex (PFC).

monitoring the activity of hundreds of millions of neurons down to single neurons, all show that at the moment when we believe that we are consciously and freely choosing to do something, the neurobiological die has already been cast. That sense of conscious intent is an irrelevant afterthought.

psychologist Uri Maoz of Chapman University, this is a contrast between “picking” and “choosing”—Libet is about picking which box of Cheerios to take off the supermarket shelf, not about choosing something major.

For example, should intending to shoot someone but missing count as a lesser crime than shooting successfully? Should driving with a blood alcohol level in the range that impairs control of a car count as less of a transgression if you lucked out and happened not to kill a pedestrian than if you did (an issue that Oxford philosopher Neil Levy has explored with the concept of “moral luck”)?[31]

I once was a teaching witness in a trial where a pivotal issue was whether eight seconds (as recorded by a CCTV camera) is enough time for someone in a life-threatening circumstance to premeditate a murder. (My two cents was that under the circumstances involved, eight seconds not only wasn’t enough time for a brain to do premeditated thinking, it wasn’t enough time for it to do any thinking, and free won’t–ness was an irrelevant concept; the jury heartily disagreed.)

we’ll now see how who we are is the outcome of the prior seconds, minutes, decades, geological periods before, over which we had no control. And how bad and good luck sure as hell don’t balance out in the end.

You view a picture of someone holding an object, for a fraction of a second; you must decide whether it was a cell phone or a handgun. And your decision in that second can be influenced by the pictured person’s gender, race, age, and facial expression. We all know real-life versions of this experiment resulting in police mistakenly shooting an unarmed person, and about the implicit bias that contributed to that mistake.[1]

How can a disgusting smell or tactile sensation change unrelated moral assessments? The phenomenon involves a brain region called the insula (aka the insular cortex). In mammals, it is activated by the smell or taste of rancid food, automatically triggering spitting out the food and the species’s version of barfing. Thus, the insula mediates olfactory and gustatory disgust and protects from food poisoning, an evolutionarily useful thing.

the versatile human insula also responds to stimuli we deem morally disgusting. The insula’s “this food’s gone bad” function in mammals is probably a hundred million years old. Then, a few tens of thousands of years ago, humans invented constructs like morality and disgust at moral norm violations.

Our insula neurons don’t distinguish between disgusting smells and disgusting behaviors, explaining metaphors about moral disgust leaving a bad taste in your mouth, making you queasy, making you want to puke. You sense something disgusting, yech . . . and unconsciously, it occurs to you that it’s disgusting and wrong when those people do X. And once activated this way, the insula then activates the amygdala, a brain region central to fear and aggression.[4]

can’t the brain distinguish beauty from goodness? Not especially. In three different studies, subjects in brain scanners alternated between rating the beauty of something (e.g., faces) or the goodness of some behavior. Both types of assessments activated the same region (the orbitofrontal cortex, or OFC); the more beautiful or good, the more OFC activation (and the less insula activation). It’s as if irrelevant emotions about beauty gum up cerebral contemplation of the scales of justice.

“Last week, you sent that other person to prison for life. But just now, when looking at this other person who had done the same thing, you voted for them for Congress—how come?” And the answer isn’t “Murder is definitely bad, but OMG, those eyes are like deep, limpid pools.” Where did the intent behind the decision come from? The fact that the brain hasn’t had enough time yet to evolve separate circuits for evaluating morality and aesthetics.[6]

lying orally (via voice mail) increased the desire for mouthwash, while lying by hand (via email) made hand sanitizers more desirable. One neuroimaging study showed that when lying by voice mail boosts preference for mouthwash, a different part of the sensory cortex activates than when lying by email boosts the appeal of hand sanitizers. Neurons believing, literally, that your mouth or hand, respectively, is dirty. Thus, feeling morally soiled makes us want to cleanse.

The scientists who first reported this general phenomenon poetically named it the “Macbeth effect,” after Lady Macbeth, washing her hands of that imaginary damned spot caused by her murderousness.[*]

hunger makes us less forgiving. Specifically, across more than a thousand judicial decisions, the longer it had been since judges had eaten, the less likely they were to grant a prisoner parole.

What’s the nuts-and-bolts biology of why males in some rodent species are monogamous and others not? Monogamous species are genetically prone toward higher concentrations of vasopressin receptors in the dopaminergic “reward” part of the brain (the nucleus accumbens). The hormone is released during sex, the experience with that female feels really really pleasurable because of the higher receptor number, and the male sticks around.

Oxytocin and vasopressin have effects that are the polar opposite of T’s. They decrease excitability in the amygdala, making rodents less aggressive and people calmer.

“T” = testosterone.