Sapolsky's late-career book, Determined, makes a claim so unfashionable that even other neuroscientists who basically agree with him try to soften it. He doesn't soften.
His argument is that free will, in any meaningful sense, doesn't exist. You don't choose your choices. They come pre-cooked by biology, history, hormones, and circumstance. By the time you experience yourself 'deciding,' the decision is already made — you're just narrating it afterward.
This sounds nihilistic. Sapolsky thinks it's actually the most compassionate thing you could believe.
the long backward look
His method in his earlier book, Behave, was a kind of forensic zoom-out. Pick any human action — say, you snap at your partner at 9 PM on a Tuesday. Then ask: what caused that?
Seconds before: your brain's amygdala was activated by a face expression or a tone of voice. Your prefrontal cortex (the brake) was tired. There were chemicals — cortisol, glucose levels, serotonin — at specific levels.
Hours before: did you sleep enough? Did you eat? Hormones?
Years before: was this dynamic familiar from your parents? Did you absorb a way of handling conflict that's playing out automatically right now?
Decades before: were you a kid in a stable home with enough food, or were you a kid whose nervous system learned that connection was dangerous?
Millennia before: humans evolved certain emotional reactions to certain cues because those reactions kept ancestors alive.
Once you do that exercise honestly, Sapolsky says, the 'I just chose to snap' explanation looks really thin. You snapped because every single one of those layers nudged you toward snapping at that exact moment.
where does 'you' come into it
The honest answer: barely. There's no clean little ghost inside your head that floats above all the layers, considers them, and freely picks. The 'you' that experiences choice is the layers themselves, talking to themselves, then telling a story afterward about how it deliberated.
Sapolsky doesn't say this to be dark. He says it because he thinks the belief in free will is what makes us cruel to each other and to ourselves.
nobody chose to be poor, addicted, anxious, mean, or lost. they got there because the layers built them that way. that doesn't excuse harm. it just changes what response makes sense.
what changes if you actually believe it
Sapolsky's argument has practical consequences. They're uncomfortable.
Punishment as moral payback stops making sense. We still need to contain people who hurt others, but doing it with vengeance built in is incoherent if nobody really 'chose' anything. You start asking different questions — what changed this person? what intervention now would change them in the other direction?
Self-blame stops making sense the same way. If you're addicted, or anxious, or you can't stop scrolling at 2 AM — Sapolsky would say no, you didn't fail. The layers — your wiring, your environment, your sleep, your dopamine system, your history — built that behaviour. The shame is a cherry on top of the wreckage. Take it off.
What's left is something closer to fierce compassion. People are doing exactly what their stack of causes makes them do, and the way to change the behaviour is to change the stack — sleep, food, environment, relationships, who you spend time with, what apps you let near your brain — not by trying harder to be 'a better person.'
the trap
There's a way to read all of this and just go limp — 'nothing's my fault, nothing I do matters.' Sapolsky would say that's also a stack of causes; you can change it.
The point isn't to dissolve. It's to soften. To stop treating yourself and other people like there's a guilty driver inside who deserves to be punished. To start treating the wiring like wiring — adjustable, responsive to inputs, deeply human.
If you've spent your life beating yourself up for not being who you think you should be by now, Sapolsky might be the most quietly liberating thinker you can read. Not because nothing matters. Because the thing in there beating you up was never the right tool to fix you.