1.2 The Illusion of Free Will

summary

Belief in free will influences behavior

Determinism is the philosophical idea that all events in reality follow a set course laid out by the initial physical conditions of the universe and the laws of nature. In the context of human free will, determinism can be summarized by the notion that the physical brain controls the mind.
Recent studies by Kathleen Vohs, Jonathan Schooler, and Roy Baumeister have provided insight into the influence that notions of determinism and free will have on human behavior. In their experiments, subjects were primed with literature that argued for determinism (no free will), free will, or were neutral.
One such study found that subjects primed with determinism were significantly more likely to cheat on a math test than those primed with free will or neutral literature.
In another experiment that had subjects provide food to volunteers, those subjects that read no-free-will literature served significantly more food that they knew the volunteers did not like compared to the neutral subjects.
These experiments show that decreased confidence in free will increases aggressive or dishonest behavior. This might be a result of the perceived lack of personal responsibility for one’s actions.
The first experiment also found that the behavior of the free will group and the control group was essentially the same, suggesting that belief in free will is a default assumption of the human mind.

Defining decisions and intentions

The study of free will focuses heavily on decision-making. A decision can be defined as a momentary mental action that forms an intention to do something. An intention can be thought of as a commitment or plan to perform an action in the future.
Decisions and intentions can be proximal or distal in time–some are for immediate action, while others are for future action.
Decisions do not necessarily need to be conscious for intentions to form.

Libet’s experiments

In the early 1980s Benjamin Libet performed an experiment that many people have claimed provided evidence against conscious free will in humans.
The experiment itself was simple: subjects were asked to flex their wrists whenever the urge arose, while they watched a fast-moving clock. They were told to record the point on the clock when their urge first consciously appeared. Subjects were regularly reminded to be spontaneous and not think in advance about when to flex.
The subjects wore EEG caps that recorded their brains’ electrical activity, as well as electrodes that recorded the muscle activity in the arm they flexed.
Libet found an interesting result: while subjects reported feeling the mental urge to flex about 200 milliseconds before actual muscle motion, EEG recordings showed elevated brain activity about 550 milliseconds before muscle motion. Libet said that, because the decision to flex was being processed unconsciously, conscious free will was not controlling the action.

Veto power as a modified form of free will

Libet did not himself argue against the existence of free will, though he did not believe it could initiate actions. Instead, he thought that there was a tiny window of opportunity for free will to veto or cancel an intention.
According to Libet, when a person becomes conscious of their intention to perform an impending action they have a 100 millisecond opportunity to prevent themselves from acting.
To find evidence for this idea Libet performed another study. Participants were instructed to prepare to flex their hands when the clock reached a certain time, but not to actually perform the action.
The experiment found that EEG activity began to increase about 1 second before the time of action and started to decrease between 250-150 milliseconds before the actual time of action, perfectly in line with Libet’s predictions about veto power.
This experiment had one major flaw: the participants never actually intended to flex, they intended to prepare to flex but then to not take the action. Libet did not measure veto power over an intention, but possibly preparation or forethought.