Does knowledge of neuroscience erode the idea of free will?

The Economist has an article that wonders whether new knowledge into neuroscience and more particularly social pathologies will erode our belief in free will. I roll my eyes every time I read an article like this one, mostly because they tend to express an uniformed view about how the brain works:

For millennia the question of free will was the province of philosophers and theologians, but it actually turns on how the brain works. Only in the past decade and a half, however, has it been possible to watch the living human brain in action in a way that begins to show in detail what happens while it is happening (see survey). This ability is doing more than merely adding to science's knowledge of the brain's mechanism. It is also emphasising to a wider public that the brain really is a just mechanism, rather than a magician's box that is somehow outside the normal laws of cause and effect.

Science is not yet threatening free will's existence: for the moment there seems little prospect of anybody being able to answer definitively the question of whether it really exists or not. But science will shrink the space in which free will can operate by slowly exposing the mechanism of decision making.

At that point, the old French proverb "to understand all is to forgive all" will start to have a new resonance, though forgiveness may not always be the consequence. Indeed, that may already be happening. At the moment, the criminal law--in the West, at least--is based on the idea that the criminal exercised a choice: no choice, no criminal. The British government, though, is seeking to change the law in order to lock up people with personality disorders that are thought to make them likely to commit crimes, before any crime is committed.

Such disorders are serious pathologies. But the National DNA Database being built up by the British government (which includes material from many innocent people), would already allow the identification of those with milder predispositions to anger and violence. How soon before those people are subject to special surveillance? And if the state chose to carry out such surveillance, recognising that the people in question may pose particular risks merely because of their biology, it could hardly then argue that they were wholly responsible for any crime that they did go on to commit.

I roll my eyes a bit whenever I read articles like this one for several reasons:

  • 1) The British government may well be collecting information in a National DNA Database, but you would have to be insanely bullish about the utility of genetic information if you think that they could usefully use that information for social surveillance.

    Evidence from the genetics of behavioral disorders suggests that even for disorders which show very high heritability, there is always a necessary environmental component. Traits like anger and violence show low heritability to start out with, so we can expect their environmental components to be even larger. Furthermore, you are dealing with genetic associations that have not been fully explicated. We can identify single nucleotide polymorphisms (SNPs) associated with aggressive behavior. We cannot at present explain why they would be associated, and they may very well be associated by random chance. Finally, many of these SNPs are present in large numbers in the population. Are they going to surveil everyone?

    Taken as a whole, those who suggest that we can use genetic information to identify people prone to criminal behavior assume a level of genetic determinism not borne out by the facts. I agree that we shouldn't single people out by their genetic risks, but it would be insane to believe that we could.

  • 2) In my opinion, knowledge of the brain is just as likely to reinforce our belief in free will as it is to erode it.

    What we have learned in the past twenty years about the brain clearly suggests that it is not a simply genetic machine -- the environment plays a clear role in shaping behavior. Even more than that, environment does not predictably shape behavior. Instead, the more we know about environmental influences on behavior, the more we find out how cognition -- how the individuals interacts with the environment -- plays an important role. I would argue that this relative importance of cognition is strongly suggestive of free will.

    Consider the example of habit. I can train a rat to run a maze, and eventually it will learn to do so. After it has learned to do it, its behavior in the maze will be guided largely by habit -- by the string of contingencies that I have created, a sort of deterministic environment. However, before this habit becomes engrained there is a preparatory phase where the rat decides how to run the maze. It develops a strategy that can be based on spatial cues or perhaps on egocentric left-right considerations. This decision of how is what characterizes cognition, and it is present even in rats.

    The presence of a period where you have to choose before habit sets in -- the presence of a period where cognition is important -- reinforces the idea that genetics and environment cannot explain all the details of behavior. If there is room for the animal to interacts with its environment -- to choose -- then there is room for free will.

  • 3) Humans can manipulate their own environment, thereby expressing their free will.

    You could argue that human behavior is determined by genetics and environment. You could argue that if I possessed a certain genetic risk, and you placed me in the right environment I would develop that pathology.

    But I could respond that the situation is artificial. Environment is not always a predetermined thing; we have control over it in degrees. Say I know that I have a genetic tendency to be aggressive. Then I can try and avoid situations where this trait will manifest itself. Say I have a genetic tendency to overeat. Then I can try and avoid situations where I am likely to be tempted by unhealthy foods.

    It is true that environment and genetics collude to influence our behavior, but our behavior can also allow us to choose our environment. We can express our free will by selecting environments most likely to create behaviors we like.

Writers and science analysts tend to get all worked up about the death of free will. In my opinion at least, rumors of its demise have been exaggerated.


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The presence of a period where you have to choose before habit sets in -- the presence of a period where cognition is important -- reinforces the idea that genetics and environment cannot explain all the details of behavior. If there is room for the animal to interacts with its environment -- to choose -- then there is room for free will.

But that merely pushes the question back one level. What constrains (or doesn't constrain) the choices? "Free will" seems to connote something like unconstrained choice. Do you really want to argue that? Or is that a strawman?

I don't really think of free will as unconstrained choice because we don't live in a world filled with unconstrained options. I think of it more as unbiased choice. Something more like "genetics and environment bias our choices." My argument is that there is a period where choice is made based on the evaluation of rewards, goals, motivations, etc. -- a period where cognition rather than habit is taking place. During this period, it seems like the genetics and the environment matter less.

A good counter-argument could be made, however, that cognition is the product of environment and genetics. I am not entirely certain how I would respond to that counter-argument.

I think an answer might be that cognition -- in addition to environment and genetics -- is also the product of previous cognition -- the way we thought before is the way we think now. This leaves in the element of choice because you can shape the way you think.

My point with this post is that the problem of free will may not even be soluble in the sense the article describes. Thus, saying that science erodes the concept of free will is sort of silly.

I think the issue is less whether there is an absolute sense of Libertarian Free Will. I've seen nothing to establish that one way or an other. Rather the issue is a closely related one of whether we are free the way we think we are free. Clearly we are not and even if we have Libertarian Free Will it is much more narrow than historically thought.

"Free will" is an almost totally-nebulous concept. So, let's look at it this way: do we have any more "free will" than a rock?

By Caledonian (not verified) on 28 Dec 2006 #permalink

The 'cognition == free will' position founders on a problem I've personally summarized as:

You can do as you wish. But you can't wish as you wish.

IOW, all of your 'choices' are constrained and in fact not 'choices' at all in the 'free will' sense.

I expect it to take a century or so before our computers reach the point where they appear to be as intelligent (with just as much free will) as we are. But no one will be able to deny their choices are in fact deterministic (in the 'all their choices can be traced as being inevitable consequences of their programming and environment' sense).

And so are ours.

By Benjamin Franz (not verified) on 28 Dec 2006 #permalink

What would shape the structure and activity of the cognition if not the genetics and the environment? How at once it might get disconnected from those?

This once again raises a basic question about the ability or propriety of science to comment on non-scientific subjects. Simply understanding the mechanisms of brain function cannot itself cast any light or shadow on the notion of free will. However, looking at the mechanisms of brain function through deterministic spectacles might. In a sense, to fear that neuroscience will erode the notion of free will is to have already invalidated the notion of free will, since this concern assumes that the only room left for free will is in the area of our scientific ignorance.

The mistake is in assuming that science necessarily entails a philosophical orientation that precludes the notion of free will. Science only precludes non-deterministic notions if one has defined science to be deterministic, but such a definition is not a necessity. The effects of scientific findings on philosophical issues will largely depend on the philosophical positions chosen beforehand by those who interpret the findings.

Besides, neuroscience could very well discover that there are normal neural processes that introduce indeterminacy into brain function. Maybe it will eventually demostrate a neurological basis for free will!

By Millard Melnyk (not verified) on 30 Dec 2006 #permalink


How does one practice science if it isn't defined to be deterministic? Why is free will not a scientific subject?

Why does indeterminacy in the brain give you free will? It just seems to make you random, completely out of control of any agent you might call the self.

You seem to be of the philosophy that things are completely relative, and that looking at the world from a different perspective will give you different answers. While it may be true for politics or art, it isn't for science. If you go off redefining science and your new science gives you an answer that conflicts with the "old" science, there is a problem. The reason science works at all is because of determinism (and I'm not leaving out quantum physics by writing this) and the universality and atemporal nature of the physical laws we've found.