Sometimes we make decisions which our subconscious might have already decided for us. Another look at the nature of free will, this time from the point of view of psychology and the famous Libet experiments.
Can human decisions be predicted? Is free will really free? In the first episode I looked at these questions from the point of view of particle physics and the difficulties in determining outcomes that chaos injects into systems. But the true authority on this question should probably be reserved for philosophers. So what do they say? There are many engaging arguments for and against free will but, unfortunately, there is no consensus. In fact philosophical positions get even more divided if we take a look at considerations of determinism and free will. Determinism, which implies that all future actions are pre-ordained and may be derived from the current state of things would seem to point in the opposite direction of free will, and conversely free will should mean that determinism is not true.
Surprisingly philosophers are not in agreement on this and there are actually those who argue that determinism and free will are compatible in what is known as the Soft Determinism Theory ( as opposed to the Hard Determinism Theory in which free will and determinism are incompatible). Without getting lost in the many paths these discussions explore let's take a look at one central argument which I have seen in serious philosophical essays as well as in recent best selling books which claims that free will is an illusion because decisions are not really made by our conscious minds. The argument is that, when a decision is made, our brains have already processed the information before it arrives at the state of consciousness and all our thought process of evaluation of the issue is irrelevant, we believe we made a decision consciously but the decision was already arrived at a few tenths of a second before by our subconscious. It is as if we are watching a drama unfold believing that we are in control of the main character's actions, when actually she is not affected by our instructions at all.
This argument is based on a series of famous experiments by Benjamin Libet. It is worth taking a moment to describe them. In Libet's experiments subjects would be asked to perform a simple action, such as moving a finger whenever they wanted to. They would also note the position of a moving dot on an oscilloscope which was used as a timer, the precise moment they felt the urge to act. Using an electroencephalogram to monitor the subject's brain activity, Libet discovered that brain activity which appeared to be related to the action of moving the finger began about a half of a second before the finger was moved, but the feeling of the urge to act was reported by subjects afterward: about 0.2 seconds before the finger was moved. In other words, when subjects were told to move a finger whenever they wished, the brain activity related to the finger's movement began before the subject reported the decision to move her finger. This is a truly amazing result, and it has many implications which I believe cannot be underestimated. But does it prove that free will does not exist?
Consider all the actions we perform in the course of a day. Many of them are executed with no input from our awareness at all.. Our conscious brain has no decision-making authority over a host of functions. the muscles in our heart which are constantly active pumping blood, the movements of our gut, the control of our body temperature and blood pressure, our immune response, the dilation of our pupils to name a few. In fact, although our emotional state can affect these functions: our blood pressure may rise with anger or excitement, our digestion may suffer when we are unhappy, our conscious brain is actually blocked from being able to control them. Since consciousness is interrupted for around eight hours every day when we sleep, it makes sense that these functions be kept going by a part of the brain that is not conscious.
Then there are activities which require us to be in a conscious state but which we are minimally aware of. Any activity we have repeated many times and have become fluent at performing falls into this category. You might take a good while pondering a decision on whether to drive to the gym for a workout, but once you are in your car, you do not take long to decide whether to brake or accelerate when the traffic light turns red.
So let's return to Libet's experiment and see what it shows us. We know that some activities are performed by our brains without the need for consciousness, like keeping our hearts beating. Some activities, like driving a car, require us to be conscious but not to make conscious decisions on our car control movements like moving our foot to press the brake pedal. But what about moving a finger during a Libet experiment at a random moment? The subject must be conscious, and believes she has initiated the action by her own volition but actually that does not appear to be the case. What Libet's experiments strongly suggest is that there are activities we think we consciously decide to do but actually have initiated already. Is free will an illusion? It appears to be in these cases, but would it be possible to say that all our conscious decisions are pre-ordered by our brains before we are aware of them?
American psychologist Edwin Locke, in his book The illusion of Determinism gives a series of energetic arguments against the idea that everything we decide is really determined through a non-conscious thought process. One interesting point that he notes is that subjects sometimes decided against moving their finger even though the electroencephalogram had already shown the activity that precedes it. Locke says that what this means is that our conscious brain may be tricked into believing it initiated an action but retains the power to veto that action.
It is certainly true that free will is not present in all of our decisions, and as Libet shows us, we may think it was through conscious volition to do some things which actually had already been initiated about a third of a second earlier by our brains. But there are also decisions which Locke calls goal-oriented, and as an example he mentions the experimental subject's decision go to the lab and participate in one of these experiments. Could that decision also be made without our being aware of it? How do we make a goal-oriented decision?
If you were invited to be a subject in an experiment, you would probably not immediately agree to go. You might first want to know a few things about it. How long will it take? Does it hurt? Do I get paid? Based on the answers to these and maybe other questions, you would make a decision. Was that decision actually arrived at 0.3 seconds before you thought you had decided? Does that really matter? Clearly a goal-oriented decision such as this one requires rational thinking and inner evaluation of the pro's and con's involved. Maybe the decision was arrived at before you are aware of it, but it was still a decision which you consciously weighed and analyzed, and the conclusion is consistent with the information you processed. In short, you were offered to participate in an experiment, you asked some relevant questions, made a decision based on the information you were given and then acted on that by going to the lab the day the experiment was scheduled. You were not obligated to go, and the decision was made consciously.
Which brings us to the insights of Nobel prize winning Israeli psychologist Daniel Kahneman and his method of dividing the thought process in two categories, which is presented in detail in his book "Thinking Fast and Slow". Thinking Fast is the way we make quick decisions which are made more reflexively, and is an almost automatic, intuitive, method of thinking, for example, the way we think about driving to the lab Thinking Slow is a deliberative thought process used for making decisions such as the ones subjects had to evaluate to decide on participating in Libet's experiments.
As I mentioned in the first episode, the definition of free will is an issue which I believe has not been fully resolved. Driving absent-mindedly and moving your finger randomly may fall into a category of actions which are not freely willed. But the series of events leading up to your acting on the "Thinking Slow" type decision to go to the lab as a subject in an experiment requires two main ingredients, namely, the combination of a non-pre-determined decision plus volition. A non-pre-determined decision PLUS volition. I offer this as the definition of Free Will.
LINKS
Quick animated explanation of Libet experiment from BBC (YouTube)
Daniel Kahneman: Thinking Fast and Slow, Talks at Google (YouTube)
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