I recently read this scientific study: Soon, C. S., Brass, M., Heinze, H. J., & Haynes, J. D. (2008). Unconscious determinants of free decisions in the human brain. Nature neuroscience, 11(5), 543.

It provides strong evidence that what we thought of as a free conscious decision is already unconsciously decided in the human brain, sometimes up to 10 seconds before. They claim a 60% success rate in prediction which is only 10% above chance which I don't see as significant but maybe it depends on the number of tests done.

Many on the internet are using the results of this study to speak out against free will. But is this study really decisive? I have observed myself and it is true I am normally an unconscious machine moving and making selections around my house without being aware that I am consciously making choices. I just get off from my computer chair and go somewhere without consciously deciding to. I select from my breakfast cereals without consciously deciding to. I run on automatic and this speaks to the wonder of the brain. But I am not a slave of the unconscious brain. If I get an itch, I can consciously choose not to act on the unconscious urge to scratch it. If I am on a no-carb diet and the smell of that baked bread is making my unconscious brain present me a desire to eat it, I can ignore it. If I am holding onto a plate so hot that it will leave blisters on my hand and BOTH my instinctual unconscious and sensible conscious brain is telling me to drop, I can consciously ignore it until the pain is gone. I have actually tried the last to see the difference between physical and mental suffering.

So what does this study prove? That what we thought was a conscious free choice was an unconscious predetermined process in the brain? Maybe. They CAN be. Do they all HAVE to be? We know that the conscious self can choose while the unconscious brain reacts. I think the key here is if the test subjects were really making conscious decisions. Is just sitting without thinking until the idea of one button presents itself to the mind a CONSCIOUS decision? Or is it letting the unconscious mind present an idea that you then feel you 'picked'? What if instead the test were done with subjects consciously flipping back and forth between concepts of "this button, that button" until they decide to stop at one? I wonder what the success rate of prediction would be then.

Maybe what this study really proves is that many of the selections we make ARE unconscious. Most of our life we are automatic. There is no free will. We are robots following a learned program. But not when there is conflict. Not when the choice matters. Then it really is a conscious decision. Maybe they could also do a study with homeless people and selection of buttons deciding whether they gain a dollar or lose a dollar.

  • 1
    It shows that scientists usually know nothing about philosophy and therefore sometimes have major glitches in the interpretations of their results. In Neurobiology, the rate is much higher.
    – Philip Klöcking
    Commented Dec 13, 2016 at 23:20
  • Also, is this a question or a question and answer paired together?
    – virmaior
    Commented Dec 14, 2016 at 1:41
  • @PhilipKlöcking - Amen to that. I wonder how cricketers manage to play their shots in the fractions of seconds they have before the ball arrives.
    – user20253
    Commented Dec 10, 2018 at 10:18

3 Answers 3


Being unconscious of a decision does not mean that you are not the one making the decision, or say anything about free will. When a trained cook adds just the right amount of salt by taste and touch "without consideration" that is still her mind, and her decision, even though it is unconscious. When athletes place their feet on slippery turf perfectly by training and instinct "without thinking" it is not like they really aren't thinking. And as automatic as these responses are, that unconscious thinking could still be either determined or free.

According to the modern theory of expertise, (grown out of experimental validation of Heidegger's analysis of modes of Being,) we all do our best work when our consciousness is not trapped into making each individual decision that determines our next step, but is instead free to plan and to observe at a higher level.

What this kind of study of thought timing in general indicates is that decision making is a continuous process and not an instantaneous event. It upholds a psychoanalytic prediction that the unconscious wish slowly becomes powerful enough to be an action, and goes through conscious processing only if it needs to be reconciled with competing alternatives in a specific way that requires explicit sequencing or particular responsibility.

Even then, the conscious event is not the decision process, it is just one stage that the decision might go through. Most of the time, this is not necessary, so it does not happen, in which case your later memory of deciding is a story you make up for memory's sake.

  • I am intrigued by your reference to Heidegger since my question was actually born out of contemplation of the question "Am I just the material brain?" due to my recent interest in nonduality. I dont know if you are familiar with the work but would you recommend his Being and Time in uncovering the nondualistic path or is it merely a dualistic work?
    – Anoop Alex
    Commented Dec 14, 2016 at 6:17
  • Heidegger is standard Western phenomenology and further subdivides experience. I think there is a path to a sort of Western take on non-dualism related to this subject, but more obliquely: through analysis of unconscious processing and the 'primary process' in psychoanalysis, which does not have a well-constructed sense of negation. Ken Wilber in 'No Boundary' tries to mine pyschoanalysis for this thread.
    – user9166
    Commented Dec 18, 2016 at 1:04

The question is: So what does this study prove? The study is Soon, et., al., "Unconscious determinants of free decisions in the human brain".

Alfred R. Mele considers this study and offers a suggestion about what these researchers were actually studying: (page28)

What are the scientists measuring or detecting several seconds before a button press? What is the neural activity associated with? My bet is a slight unconscious bias toward a particular button on the next press. Possibly, the bias gives the participant about a 60 percent chance of pressing that button next.

The question then arises what does this have to do with making a conscious decision. Mele then remarks: (page 29-30)

The participants in the fMRI study did arbitrarily pick a button to press - sometimes the one on the left, and sometimes the one on the right. My concern now is that this kind of picking may not be very similar to choosing or deciding in situations in which a lot of conscious weighing of reasons - pros and cons - goes into the choice or decision. How similar is the arbitrary picking of a button to a decision to ask one's spouse for a divorce - or to change careers or start a small business - after protracted reflection on reasons for and against that decision? If arbitrary picking is not very similar to these other decisions, claiming that what happens in instances of arbitrary picking also happens in instances of complicated, painstaking decision making is a huge stretch.

Mele's conclusion is the following: (page 30)

But slight biases certainly don't seem to rule out free will. They don't dictate or compel behavior. They're nothing more than nudges.

The OP notes: Many on the internet are using the results of this study to speak out against free will.

Bo Bennett describes a logical fallacy that he calls the "Far-Fetched Hypothesis" fallacy. He describes it as follows:

Offering a bizarre (far-fetched) hypothesis as the correct explanation without first ruling out more mundane explanations.

The claim that this experiment rules out free will could be viewed as a far-fetched hypothesis especially given Mele's explanation of unconscious bias to press one button over the other.

Bennett, B. "Far-Fetched Hypothesis" Logically Fallacious https://www.logicallyfallacious.com/tools/lp/Bo/LogicalFallacies/96/Far-Fetched-Hypothesis

Mele, A. R. (2014). Free: why science hasn't disproved free will. Oxford University Press.

Soon, C. S., Brass, M., Heinze, H. J., & Haynes, J. D. (2008). Unconscious determinants of free decisions in the human brain. Nature neuroscience, 11(5), 543. https://www.researchgate.net/publication/5443390_Unconscious_determinants_of_free_decisions_in_the_human_brain

  • Is Mele discussing this specific study? It's not clear from your answer.
    – E...
    Commented Dec 9, 2018 at 18:37
  • @Eliran Yes, he refers to this specific study. I updated the answer to hopefully make that clear. Commented Dec 9, 2018 at 19:30

Not an answer to the question, rather support for a counter argument.

The brain has two modes of operation: automatic and voluntary. But the distinction isn't as discrete as one might think. For example learning a new skill like juggling or playing tennis. At first there is a lot of conscious intervention in how you move, the timing of your actions etc. As your proficiency increase many actions (mostly the successful ones) will become reflex (automatic). Succinctly: (most) reflexes are conscious actions that were judged to be effective.

We can already identify several different (relevant) kinds of decisions. In order, firstly :conscious action decisions, second: conscious value judgments of actions, third: fully reflexive action decisions, fourth: Automatic (subconscious) value judgments on reflexive actions, fifth: conscious value judgments of reflexive actions. Rinse and repeat.

Now think of how awkward one feels when trying to do something novel, consciously driving every action, and how fluid your motions are in automatic (reflex) mode. The reason for this is that a fully conscious decision takes longer(more processing power) than a reflex. Furthermore the types of decisions are carried out in different parts of the brain i.e. in parallel, so sometimes voluntary action may countermand an involuntary action already in progress.

Now for Soon Et al to say something about Consciousness they would have to take into account all the types of decisions. They would also have to look at the situation i.e. is the task new or well practiced, which mental functions are engaged: visual, language, auditory... and what functions each subject have preference for...

But wait there is more: stress, health, glucose levels, and many more factors can influence different decision types in various ways. And then: a subject can be passively waiting to be presented with a choice, in which case the (thought) process is, make a decision on the choice, decide which button corresponds, decide on the action; or: a subject can decide, prior the choice, which button corresponds to which choice (automating it) and subsequently have a shorter decision process.

  • There is most likely many more "types" of decisions. Individuals may have different sets of types. All types aren't always engaged in every task.
    – christo183
    Commented Dec 10, 2018 at 6:08

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