Determined: A Science of Life without Free Will

by Robert M. Sapolsky

emergent complexity, while being immeasurably cool, is nonetheless not where free will exists, for three reasons:

unpredictable doesn’t mean undetermined. Even if a system is emergent, that doesn’t mean it can choose to do whatever it wants; it is still made up of and constrained by its constituent parts, with all their mortal limits and foibles.

Were I to chicken out and end this pair of chapters right here, the conclusions would be that, yes, Laplacian determinism really does appear to fall apart down at the subatomic level; however, such eensy-weensy indeterminism is vastly unlikely to influence anything about behavior; even if it did, it’s even more unlikely that it would produce something resembling free will; scholarly attempts to find free will in this realm frequently strain credulity.

transcription factors, which turn genes on or off; the uneven split of transcription factors when the cell divides means the two cells will differ in their gene regulation.

Yup, the single electron passes through both slits simultaneously. It’s in two places at once. Turns out that it’s more than just two places. The exact location of the electron is indeterministic, distributed probabilistically across a cloud of locations at once, something termed superposition.

You already know what will happen—each individual electron passes through both slits at once, as a wave. But no; each electron now passes through one slit or the other, randomly. The mere process of measuring, documenting what happens at the double-slit wall causes the electrons (and, as it turns out, streams of light, made up of photons) to stop acting as waves. The wave function “collapses,” and each electron passes through the double-slit wall as a singular particle. Thus, electrons and photons show particle/wave duality, with the process of measurement turning waves into particles.

known as the Copenhagen interpretation, reflecting its being championed by the Copenhagen-based Niels Bohr. In his words, “Those who are not shocked when they first come across quantum theory cannot possibly have understood it.”[*8]

Next weirdness.[*9] Two particles (say, two electrons in different shells of an atom) can become “entangled,” where their properties (such as their direction of spin) are linked and perfectly correlated. The correlation is always negative—if one electron spins in one direction, its coupled partner spins the opposite way.

And as the strangest feature, when the state of one particle is altered, the complementary change in the other occurs instantaneously[*11]

Shoot a stream of electrons at a wall. As we know, each travels as a wave, superposition dictating that until you measure its location, each electron is probabilistically in numerous places at once.

Particles can be in multiple places at once, can communicate with each other over vast distances faster than the speed of light, making both space and time fundamentally suspect, and can tunnel through solid objects.

Then there’s New Age entrepreneur Deepak Chopra, who, in his 1989 book Quantum Healing, promises a pathway to curing cancer, reversing aging, and, heavens to Betsy, even immortality.[*2]

The starting point here is the idea that quantum effects, down there at the level of electrons entangling with each other, will affect “biology.” There is precedent for this concerning photosynthesis.

Trying to pull free will out of electrons in the brain is the immediate challenge—can quantal effects bubble upward, amplify in their effects, so that they can influence gigantic things, like a single molecule, or a single neuron, or a single person’s moral beliefs? Nearly everyone thinking about the subject concludes that it cannot happen because, as we’ll soon cover, quantal effects get washed out, cancel each other out in the noise—the waves of superposition “decohere.”

As summarized by one philosopher, “The law of large numbers, combined with the sheer number of quantum events occurring in any macro-level object, assure us that the effects of random quantum-level fluctuations are entirely predictable at the macro level, much the way that the profits of casinos are predictable, even though based on millions of ‘purely chance’ events.”

So the notion that random, indeterministic quantum effects can bubble all the way up to behavior strikes me as a little dubious. Moreover, nearly all the scientists with the appropriate expertise think it is resoundingly dubious.

As a brief reminder: When an action potential occurs in a neuron, it goes hurtling down the axon, eventually reaching all of the thousands of that neuron’s axon terminals. As a result, packets of neurotransmitter are released from each terminal.

Therefore, an action potential doesn’t really cause the release of neurotransmitter from all the vesicles in each axon terminal. More correctly, it causes releases from all of the vesicles in the “readily releasable pool.” And neurons can regulate what percentage of their vesicles are readily releasable versus in storage, a way of changing the strength of the signal across the synapse.

There’s a whole cascade of molecules involved in the process of an action potential causing vesicles to dump their neurotransmitter into the synapse—ion channels open or close, ion-sensitive enzymes are activated, a matrix of proteins holding a vesicle still in its inactive state has to be cleaved, a molecular machete has to cut through more matrix to allow the vesicle to then move toward the neuron’s membrane, the vesicle has to now dock to a specific release portal in the membrane.

because it turns out that the mechanistic cascade for spontaneous vesicular release is different from the cascade for release evoked by an action potential.

—Moreover, the process of spontaneous vesicular release is regulated by factors extrinsic to the axon terminal—other neurotransmitters, hormones, alcohol, having a disease like diabetes, or having a particular visual experience can all alter spontaneous release

It turns out that when the muscle has been quiet for a while, a part of it (called the muscle spindle) can make the neurons more likely to have spontaneous action potentials—when

the default network is very active when they are daydreaming, aka “mind-wandering.” The network is most heavily regulated by the dlPFC.

if you stimulate someone’s dlPFC, you increase activity of the default network.

Why? Speculation is that it’s to take advantage of the creative problem solving that we do when mind-wandering.[19]

Back, once again, to the show-me scenario—if free will exists, show me a neuron(s) that just caused a behavior to occur in the complete absence of any influences coming from other neurons, from the neuron’s energy state, from hormones, from any environmental events stretching back through fetal life, from genes. On and on. And none of the versions of ostensibly spontaneous activation of a single vesicle, synapse, neuron, or neuronal network constitutes an example of this. None are truly random events that could be directly rooted in quantum effects;

If our behavior were rooted in quantum indeterminacy, it would be random.

“Quantum indeterminism gives us no help with the free will problem because that indeterminism introduces randomness into the basic structure of the universe, and the hypothesis that some of our acts occur freely is not at all the same as the hypothesis that some of our acts occur at random….

if quantum mechanics actually played a role in supposed free will, “every thought and action would seem to merit the statement ‘I don’t know what came over me.’ ” Except, I’d add, you wouldn’t actually be able to make that statement, since you’d just be making gargly sounds because the muscles in your tongue would be doing all sorts of random things.

When we argue about whether our behavior is the product of our agency, we’re not interested in random behavior,

We’re interested in the consistency of behavior that constitutes our moral character.

It’s why funerals so often include a eulogy from that person’s oldest friend, a historical witness to consistency: “Even when we were in grade school, she already was the sort of person who…”

The first is evolution—the random physical chemistry of mutations occurring in DNA provides genotypic variety, and natural selection is then the filter choosing which mutations get through and become more common in a gene pool.

Filtering out nonsense might prevent quantum indeterminacy from generating random behavior, but how you came to have that filter is the antithesis of free will.

Quantum indeterminacy is beyond strange, and in the legendary words of physics god Richard Feynman, “If you think you understand quantum mechanics, you don’t understand quantum mechanics.”[*25]

However, there is no evidence that those sorts of quantum effects bubble up enough to alter behavior, and most experts think that it is actually impossible—quantum strangeness is not that strange, and quantum effects are washed away amid the decohering warm, wet noise of the brain as one scales up.

there is the fatal problem that all it would produce is randomness. Do you really want to claim that the free will for which you’d deserve punishment or reward is based on randomness?

Why did that behavior—dastardly, noble, or ambiguously in between—just occur? Because of what happened a second before, and a minute before, and a…The easy takeaway from the first half of this book is that the biological determinants of our behavior stretch widely over space and time—responding

Just to restate that irritatingly-familiar-by-now notion, we are nothing more or less than the sum of that which we could not control—our biology, our environments, their interactions.

evolution produces genes marked by the epigenetics of early environment, which produce proteins that, facilitated by hormones in a particular context, work in the brain to produce you. A seamless continuum leaving no cracks between the disciplines into which to slip some free will.

We can’t successfully wish to not wish for what we wish for; we can’t announce that good and bad luck even out over time, since they’re far more likely to progressively diverge.

It’s not the case that while our natural attributes and aptitudes are made of sciencey stuff, our character, resilience, and backbone come packaged in a soul. Everything is turtles all the way down,

your frontal cortex’s actions are the result of the exact same one-second-before-one-minute-before as everything else in your brain.

And as a result, there are really important things that can’t be predicted, that can never be predicted. But nonetheless, every step in the progression of a chaotic system is made of determinism, not whim.

the component parts remain precisely as simple, and they can’t transcend their biological constraints to contain magical things like free will—a

And yes, truly indeterministic things seem to happen way down at the subatomic level. Nonetheless, it’s not possible for that level of weirdness to percolate all the way up to influence behavior, and besides, if you base your notion of being a free, willful agent on randomness, you got problems.

people hold on to the notion of free will with ferocious tenacity.

In the time it has taken you to read this paragraph, two different scientists have discovered the function in the brain of some gene and are already squabbling about who did it first. Unless the process of discovery in science grinds to a halt tonight at midnight, the vacuum of ignorance that we try to fill with a sense of agency will just keep shrinking.

If free will is a myth, and our actions are the mere amoral outcome of biological luck for which we are not responsible, why not just run amok?

So if people accept that there is no free will, will everyone just run amok? Some research appears to suggest exactly that.