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.

And when people claim that there are causeless causes of your behavior that they call “free will,” they have (a) failed to recognize or not learned about the determinism lurking beneath the surface and/or (b) erroneously concluded that the rarefied aspects of the universe that do work indeterministically can explain your character, morals, and behavior.

you observe a behavior and can answer why it occurred: as just noted, because of the action of neurons in this or that part of your brain in the preceding second.[*3] And in the seconds to minutes before, those neurons were activated by a thought, a memory, an emotion, or sensory stimuli. And in the hours to days before that behavior occurred, the hormones in your circulation shaped those thoughts, memories, and emotions and altered how sensitive your brain was to particular environmental stimuli. And in the preceding months to years, experience and environment changed how those neurons function, causing some to sprout new connections and become more excitable, and causing the opposite in others.

Why did that behavior occur? Because of biological and environmental interactions, all the way down.[*4] 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.

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.

I have listened to many arguments from those who are convinced we have free will, and yet none have been as convincing as the arguments from neurobiolgists ike Sapolsky and Harris who argue we do not.

however, 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.

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.

Sometimes this is because of 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;

I’ve been carpetbagging in a number of different fields related to behavior. Which I think has made me particularly prone toward deciding that free will doesn’t exist.

you can’t disprove free will with a “scientific result” from genetics—genes in general are not about inevitability but, rather, about vulnerability and potential, and no single gene, gene variant, or gene mutation has ever been identified that falsifies free will;[*6] you can’t even do it when considering all our genes at once.

put all the scientific results together, from all the relevant scientific disciplines, and there’s no room for free will.[*7]

even though each discipline has a hole that precludes it from falsifying free will, at least one of the other disciplines compensates for it. Crucially, all these disciplines collectively negate free will because they are all interlinked, constituting the same ultimate body of knowledge.

the fields of “neurochemistry,” “genetics,” and “evolutionary biology” can’t be separated.

I haven’t believed in free will since adolescence, and it’s been a moral imperative for me to view humans without judgment or the belief that anyone deserves anything special, to live without a capacity for hatred or entitlement. And I just can’t do it.

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.

No magic or fairy dust involved, no substance dualism, the view where brain and mind are separate entities.[*10] Instead, this deterministic world is viewed as compatible with free will. This is roughly 90 percent of philosophers and legal scholars, and the book will most often be taking on these “compatibilists.”

Again, my goal isn’t to convince you that there’s no free will; it will suffice if you merely conclude that there’s so much less free will than you thought that you have to change your thinking about some truly important things.

In 1848 at a construction site in Vermont, an accident with dynamite hurled a metal rod at high speed into the brain of a worker, Phineas Gage, and out the other side. This destroyed much of Gage’s frontal cortex, an area central to executive function, long-term planning, and impulse control.

170 years later, we understand how the unique function of your frontal cortex is the result of your genes, prenatal environment, childhood, and so on

If a compatibilist has not wrestled through being challenged by knowledge of the biology of who we are, it’s not worth the time trying to counter their free-will belief.

Here’s the challenge to a free willer: Find me the neuron that started this process in this man’s brain, the neuron that had an action potential for no reason, where no neuron spoke to it just before. Then show me that this neuron’s actions were not influenced by whether the man was tired, hungry, stressed, or in pain at the time. That nothing about this neuron’s function was altered by the sights, sounds, smells, and so on, experienced by the man in the previous minutes, nor by the levels of any hormones marinating his brain in the previous hours to days, nor whether he had experienced a life-changing event in recent months or years. And show me that this neuron’s supposedly freely willed functioning wasn’t affected by the man’s genes,

Show me a neuron (or a group of neurons, or an entire 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.

If a superhuman knew the location of every particle in the universe at this moment, they could accurately predict every moment in the future. Moreover, if this superhuman (eventually termed “Laplace’s demon”) re-created the exact location of every particle at any point in the past, it would lead to a present identical to our current one. The past and future of the universe are already determined.

despite the world being deterministic, things can change. Brains change, behaviors change. We change. And that doesn’t counter this being a deterministic world without free will. In fact, the science of change strengthens the conclusion;

Randomly pick any of the graduates. Do some magic so that this garbage collector started life with the graduate’s genes. Likewise for getting the womb in which nine months were spent and the lifelong epigenetic consequences of that. Get the graduate’s childhood as well—one filled with, say, piano lessons and family game nights, instead of, say, threats of going to bed hungry, becoming homeless, or being deported for lack of papers.

Trade every factor over which they had no control, and you will switch who would be in the graduation robe and who would be hauling garbage cans. This is what I mean by determinism.

And where did that intent come from in the first place? This is so important because, as we will see, while it sure may seem at times that we are free do as we intend, we are never free to intend what we intend.

(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.

once again, we can tell if you’ll go for “ketch-up” or “cats-up” from the activity of neurons before you believe you decided.

These are the core findings in virtually every debate about what neuroscience can tell us on the subject. And I think that at the end of the day, these studies are irrelevant.

the readiness potential, 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. Read technical papers on biology and free will, and in 99.9 percent of them, Libet will appear, usually by the second paragraph.

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). This made sense, as the PFC is where executive decisions are made.

To simplify a bit, once having decided, the PFC passes the decision on to the rest of the frontal cortex, which passes it to the premotor cortex, then to the SMA and, a few steps later, on to your muscles.[*6] Supporting the view of Haynes having spotted decision-making farther upstream, the PFC was making its decision up to ten seconds before subjects felt they were consciously deciding.

In fascinating related studies, he has shown that neurons in the hippocampus that code for a specific episodic memory activate one to two seconds before the person becomes aware of freely recalling that memory.

Thus, three different techniques, 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.

Another study showed that if you feel happy, you perceive that conscious sense of choice sooner than if you’re unhappy, showing how our conscious sense of choosing can be fickle and subjective.

Meanwhile, other studies used manipulations straight out of the playbook of magicians and mentalists, with subjects claiming agency over events that were actually foregone and out of their control.

Dartmouth philosopher Adina Roskies, for example, views Libet-world picking as a caricature of real choice, dwarfed even by the complexity of deciding between tea and coffee.

Haynes’s group brain-imaged subjects participating in a nonmotoric task, choosing whether to add or subtract one number from another; they found a neural signature of decision coming before conscious awareness, but coming from a different brain region than the SMA (called the posterior cingulate / precuneus cortex). So maybe the pick-your-charity scientists were just looking in the wrong part of the brain—simple brain regions decide things before you think you’ve consciously made a simple decision, more complicated regions before you think you’ve made a complicated choice.[18]

Does a preconscious signal like a readiness potential ever occur and despite that, the movement doesn’t then happen? Does a movement ever occur without a preconscious signal preceding it? Combining these two questions, how accurately do these preconscious signals predict actual behavior?

subjects were hypnotized and implanted with a posthypnotic suggestibility that they make a spontaneous Libet-like movement. In this case, when triggered by the cued suggestion, there’d be a readiness potential and the subsequent movement, without conscious awareness in between. Consciousness is an irrelevant hiccup.[24]

it’s hugely important if the preconscious decision requires consciousness as a mediator. Why? Because during that moment of conscious mediation we should then be expected to be able to veto a decision, prevent it from happening. And you can hang moral responsibility on that.[26]

Even if we don’t have free will, do we have free won’t, the ability to slam our foot on the brake between the moment of that conscious sense of freely choosing to do something and the behavior itself? This is what Libet concluded from his studies. Clearly we have that veto power.

As such, a readiness potential doesn’t constitute an unstoppable decision, and one would generally look the same whether the subject was definitely going to push a button or there was the possibility of a veto.[*18]

What’s the neurobiology of a gambler on a losing streak who manages to stop gambling, versus one who doesn’t?[*21] What happens to free won’t when there’s alcohol on board? How about kids versus adults? It turns out that kids need to activate more of their frontal cortex than do adults to get the same effectiveness at inhibiting an action.

Stage one, the “free” part: your brain spontaneously chooses, amid alternative possibilities, to generate the proclivity toward some action. Stage two, the “will” part, is where you consciously consider this proclivity and either green-light it or free-won’t it.

Thus, “our brains” generate a suggestion, and “we” then judge it; this dualism sets our thinking back centuries. The alternative conclusion is that free won’t is just as suspect as free will, and for the same reasons. Inhibiting a behavior doesn’t have fancier neurobiological properties than activating a behavior, and brain circuitry even uses their components interchangeably.

For Libetians, these studies show that our brains decide to carry out a behavior before we think that we’ve freely and consciously done so. But given the criticisms that have been raised, I think all that can be concluded is that in some fairly artificial circumstances, certain measures of brain function are moderately predictive of a subsequent behavior. Free will, I believe, survives Libetianism. And yet I think that is irrelevant.

Where did that intent come from in the first place? If you don’t ask that question, you’ve restricted yourself to a domain of a few seconds. Which is fine by many people.