This is the final post in a four-part blog series on the science of free will.
So far in this series we have heard from scientists on both sides of the debate over free will. Now, we'll go after a different question: Does free will matter?
Experimental psychologists have been studying what happens when our beliefs about free will are altered. Their results suggest that our opinions about free will may be even more important than free will itself, for if we come to believe that free will is truly an illusion, society might become a less friendly place.
In 2008, Kathleen Vohs, a psychologist and marketing professor at the University of Minnesota, ran an experiment to probe how subjects' beliefs about free will influence their behavior. In each trial, one group of subjects read statements asserting that that our actions are completely predetermined by environmental and genetic factors--that there is no free will. A second group read neutral statements. Then, the participants were given a test of character. In one case, they were asked to complete a computerized math test that was "flawed"--it sometimes "accidentally" showed the correct answer. Subjects were instructed to quickly click away the answer and ignore it, but they had the opportunity to cheat of course.
In a similar experiment, subjects completed another test and were instructed to take a certain amount of money from an unattended source for each correct answer that they scored. Though subjects believed no one was watching--and thus they could take as much money as they wanted--Vohs and her colleagues were actually monitoring the pot.In both experiments, Vohs discovered that subjects who read the deterministic statements were more likely to cheat: They were more likely to "peek" at the answers on the computer test and they took more money than they deserved.
Marcel Brass, an experimental psychologist at the University of Ghent in Belgium, has taken studies like Vohs's one step further. He found that beyond shaping petty behaviors, the induced disbelief in free will can actually influence how our brains function. Brass looked at what happens to the signals in the brain involved in movement preparation when subject's beliefs about free will are altered. Brass and his team found that a signal believed to indicate movement preparation was reduced in those induced to disbelieve in free will, as recorded by EEG. This means belief in free will alters us both psychologically and physically.
In another experiment, Brass and his team showed that subjects believe they have made conscious decisions even when they have acted on impulse. In the trials, subjects were seated in front of a computer and a button. Subjects were instructed to be ready to push the button at any time. The computer would say, "GO" which meant that the subject should immediately press the button, or "STOP" where they should stop themselves. Sometimes it would say "DECIDE," meaning that they should not act impulsively but should consciously take time to think about whether or not to press the button and then either press it or not.
Some subjects accidentally immediately hit the button at the "DECIDE" signal. Subjects were questioned after each trial about whether or not they actually took time and consciously decided to press the button or not. Interestingly, some subjects who said they did take time to decide had the same reaction time as those who could not stop themselves and accidentally pressed the button. So we are not perfect at judging whether we used our conscious will to make a decision or acted spontaneously. Conscious intention may be less of a driving force in our actions than we realize.
Brass notes that this does not mean we have no intentionality at all; it is just another piece of data in this complicated problem. "You have to look at what the science is saying. It is not saying intentionality is always a reconstructed thing. In this experiment it was, with certain people, in certain trials... In psychology we always have probabilistic statements. We never say with 100% certainty, we know what will happen."
We began this series asking whether science has brought us any closer to understanding whether free will exists. We've discovered that the brain works in ways that challenge our everyday intuition and that physical movements may very well begin before we have consciously planned them. But what about the big decisions that define our lives and who we are? What career to pursue, whether--and whom--to marry, what values to hold most tightly?
I know how I use my free will in my own life. It doesn't matter whether that is an illusion, it keeps me out of trouble. Vohs and others have proven this, and it works for me. We have to operate in a way that works with the world we can see and understand. But as for what free will actually is or is not in a scientific sense? I don't believe I have gotten any closer. In fact, I think the essential question--"What is free will?"--still has not been answered. Scientists and philosophers seem to take on the philosophy of Humpty Dumpty in Lewis Carroll's "Through the Looking Glass" when they talk about free will: "'When I use a word,' Humpty Dumpty said in a rather scornful tone, 'it means just what I choose it to mean--neither more nor less.'"