Brain Signals Show Up Seven Seconds Early, and the Researcher Still Says Free Will Survives
The Libet and Haynes experiments show brain signals appearing half a second to seven seconds before ‘you decide’, but the researcher behind them denies this amounts to the absence of free will; compatibilism holds that will may be a macro-level emergent property of microscopic brain processes, the way temperature emerges from atoms.
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If choice is an illusion, then ‘I’ am not the one deciding
A genre of video circulates on social platforms: people announce ‘I just remembered I have free will’ and then do something arbitrary — dumping all the cutlery into a drawer unsorted, climbing into the attic to keep eating chips like a goat. The whole performance celebrates freedom, while another corner of the internet insists everything was settled in advance. The host points out that scientists have been publishing papers arguing free will does not exist for decades, so the question is not a joke: if choice is an illusion, is ‘I’ still the one making decisions?
— Wendy ZuckermanRead one line saying free will is an illusion and people cheat more
Merrill cites a body of psychology experiments: subjects are given something to read along the lines of ‘science has proven free will is an illusion’, and then their behaviour is observed. People turn out to be more willing to cheat, less willing to help others, and more likely to behave aggressively. Wendy's reaction is blunt: if I come away from this episode convinced I have no free will, I can just say ‘I had no choice’ and dodge responsibility for everything. Merrill corrects her — it does not necessarily play out that way — but the answer to the free will question really does affect people's sense of responsibility and their moral behaviour.
— Merrill HornPeople are trains stuck on rails, unable to escape the laws of physics
The usual definition of free will is this: when choosing between chocolate and caramel, it is ‘I’ who decides, and it is not a roll of the dice. But classical physics describes a clockwork universe: a ball rolls down a hill because of gravity, and every event is determined by prior causes. A human body is likewise a collection of molecules, and in principle the next step could be predicted from the laws of physics and biology. John Dylan Haynes, at the Charité in Berlin, uses the image of railway tracks: a person is like a train stuck on rails, unable to leave the path that natural law has laid out.
— Merrill HornThe brain settles it seven seconds early and consciousness is just a passenger
Benjamin Libet's experiments in the 1980s had already found that roughly half a second before subjects reported ‘deciding to move’, a small signal appeared in the scalp EEG. John replicated and extended this with fMRI: 14 subjects freely chose to press a left or right button, and the brain signal appeared a full 7 seconds before people reported making the decision. Wendy times out 7 seconds live on air to show how long that is — your brain may have prepared the decision well in advance, with consciousness riding along as a passenger who finds out afterwards.
— Merrill HornSixty percent accuracy cannot carry the claim that the decision is already made
John used machine learning on the brain signals to see whether left or right could be predicted before the subject was aware of choosing. Accuracy came out around 60% — better than a coin flip's 50%, but far from perfect. Merrill does not buy 60%; another group, using a different technique, pushed the prediction rate to 80% in the instant before the decision. This research became ammunition in the argument: John's paper has been cited by other papers nearly 3,000 times. For those on the opposing side, the core message is that the brain has already leaned toward one option while you have no idea.
— Merrill HornTemperature isn't in any single atom, and choice is just as real
The theoretical physicist Sean Carroll offers a compatibilist framework: weather forecasting relies on temperature, pressure and humidity, but you cannot find temperature in a single atom — those quantities only appear once a great many atoms are gathered together, which is what emergence means. Waves in the ocean likewise exist only at the macro level, yet nobody doubts the ocean is real. By analogy, he argues, the ‘you’ that makes decisions is the macro-level emergence of all the brain's microscopic processes. Every neuron underneath obeying the laws of physics does not make the experience of choosing at the higher level an illusion.
— Merrill Horn / Sean CarrollPressing a button tells you nothing about whether to have children
Merrill aims at the weak point of the skeptics' case: the laboratory task is pressing one button or flicking a wrist, which is a long way from ‘should I have children’ or ‘should I marry this person’. Extrapolating from the most basic motor decisions to major life choices is itself an untested assumption. Even granting that brain signals precede awareness, that does not falsify free will — it only shows that decision-making is a more complicated process than we assumed.
— Merrill HornNeurons fire first, and it is still ‘you’ doing the deciding
John Dylan Haynes, who ran the 7-second experiment, clarifies it himself: the 2008 paper deliberately did not say ‘there is no free will’, because he wanted to publish the finding first and leave the philosophical dispute aside. He personally leans toward the view that even if neurons fire before the decision, it is still ‘you’ who is deciding — which requires bringing unconscious processes into the definition of the self. The episode therefore lands not on ‘free will has been defeated’ but on ‘free will needs to be understood differently’.
— John Dylan HaynesIn their own words · checked verbatim
in these videos, you'll see people saying, I just remember, I have free will.
Wendy Zuckerman0:00
And these studies find that people will act worse.They're more likely to cheat less likely.
Merrill Horn5:00
Like you can't look at one little atom and see that it's 20 degrees outside.
Merrill Horn23:11
We were quite careful, So, by the way.Not to say in that 2008 paper that there's no free will.
John Dylan Haynes30:00
Figures
| How far the readiness potential preceded the conscious decision in Libet's experiment | about half a second | 9:41 |
| How far the brain signal preceded the reported decision in Haynes's fMRI experiment | 7 seconds | 14:05 |
| Machine-learning accuracy predicting the left/right button press (John's experiment) | about 60% | 16:25 |
| Prediction accuracy in another group's experiment | over 80% | 17:36 |
| Citations of Haynes's 2008 paper by other papers | close to 3,000 | 17:36 |
| Number of subjects in the fMRI experiment | 14 | 14:05 |
| References cited in this episode | 22 | 31:15 |
Glossary
- Emergence
- A new property that appears once a great many microscopic parts form a whole, the way temperature emerges from atoms.
- Clockwork universe
- The classical-physics picture in which everything runs like a wound-up clock and every event is determined by the prior state.
- fMRI (functional magnetic resonance imaging)
- An imaging technique that measures where brain activity is located; Haynes used it to record signals preceding a decision.
- EEG (electroencephalography)
- Electrodes placed on the scalp to measure electrical activity; Libet used it to discover the readiness potential.
How to listen
Founders who keep circling the question of whether their choices are really their own, product leads who have to draw lines of decision-making responsibility, and tech readers who have been fed fatalism by algorithmic feeds without ever encountering compatibilism.
The sponsor reads at the front and back can be skipped; the substance runs from 0:00 to 31:15.