Interview with David Eagleman – “Brains are like fingerprints”

How much free will does a criminal have? I sat down with neuroscientist David Eagleman to talk about the prediction of criminal behavior, the mind of Anders Breivik and attractive psychopaths.

Mensel: In your book, you describe how what we believe to perceive is actually just a fraction of what processes go on in our minds. From that, you conclude that a person’s ability to choose depends to a large part on factors we aren’t necessarily aware of. Does that mean decision-making works different for everyone?
Eagleman: Exactly – brains are like fingerprints, in the sense that they are different for each person. Part of the problem is that we always assume everybody to be just like us. For the most part, as a species, that is true: People are generally alike, there is a circle of cooperativity. But even though some people are artists, accountants, some are Democrats and some Republicans – but it also turns out that they can be quite different even way outside those circles. If you look at someone like Anders Breivik in Norway, he’s got a brain that essentially looks like yours from the outside, its got the same pieces and part, but it also has fundamental differences in it. It is impossible to step into his shoes. Neurally, you can’t get into his head and really know what it is like to be him because it can be very different on the inside of different people.

Mensel: So if the way people like Breivik think is so fundamentally different from other people do, how does this difference develop?
Eagleman: The way your brain develops is a complex interaction of genes and environment, so all the genes you come to the table with plus every experience you ever have, including what happens in your mothers womb, all your childhood experiences, whether there is lead paint on the wall and certain toxins in the air or whether there’s abuse or drugs. Everyone of these things changes the trajectory of brain development. As a result, brains come out very individualized – sort of the same process as snowflakes – since just the tiny details like the wind and temperature makes each snowflake come out being quite different.

Mensel: Yet we believe that everyone has the same general preconditions when it comes to making decisions. If our environment affects our thinking this much, it also affect the morality that underlies out actions.
Eagleman: That’s right: But because of the rules of natural selection, most of the population ends up in the same general arena. Most of us would not murder somebody. But it is also the case that most people will cheat in little ways and will break small laws. But generally, people have a group morality that’s held into place by social fabric.

Mensel: But within that group, there’s a certain legroom for people to interpret the rules?*
Eagleman: Something that I think is just getting appreciated in neuroscience is the power of the social fabric and its change. Things can become very different, if people start thinking “Alright, it’s okay to do that now”. Whole countries can display the most monstrous behavior just because somebody else did it.

Mensel: If all of these things, such as the social norm and the environment we live in affects our thinking, how much free do people even have?
Eagleman: It is not clear that we have free will at all. I happen to be hopeful that maybe there is something and that free will does exist. But if it does, it is clear that our science is too young to understand what that means. Currently we do not have any way of understanding how to fit that into a story with pieces, parts and machinery. But what seems clear to me and what I argue in the book is that if we have free will, it is much smaller than what anybody has ever thought. It is constrained in how much it can steer the system. All your genes and environments create a particular brain, which has a certain direction to it. Free will, if it exists, might be able to modulate it just a little bit – steer you a bit to the left of the right – but you cannot become like Anders Breivik and he cannot become like you by using free will, because your brains are too different.

Mensel: Does that mean that the path he ended up taking has been set a long time ago?
Eagleman: When something really tragic like this happens, if feel like the general public really wants some satisfaction of blame, and they want to feel their anger – which is totally understandable. But it is the case that events in his life or even before he came into existence, such as his genetics, gave him the kind of brain that he has.

Mensel: I guess what I find most puzzling are the ramifications: Breivik, to stick with the example, is now being put in front of court, where it is assumed that his actions were guided by nobody else but him.
Eagleman: I think that is really easy to fix. We will of course continue to take bad people off the streets, people who are breaking the social contract we all agree on, but the whole point of a trial, aside from assessing guilt, is to figure out what to do with the person. With a brain-compatible legal system, the idea is to understand the future dangerousness of a person. With somebody like Breivik, it makes sense to go to court, talk to him and figure out what made him do what he did. That is of course an extreme example, where the outcome is clear – he will be locked away for the rest of his life. Norway has a maximum sentence of 21 years, after which they can revisit the case and re-sentence for an additional 5 years. I suspect they will keep him locked up forever, because his actions alone already suggest to us that there’s something really abnormal about his brain. Even if a brain scan does not reveal anything obvious, or if for some reason we did not have a psychotic label for what he did, his actions are so statistically abnormal that his brain is statistically abnormal.

Mensel: In Germany we had a large controversy over doing just that – there had been a law to keep people locked up, even after their sentence had expired – the reasoning was, that someone like a serial rapist should not be let back on the streets. That law was overturned in court, among other things also because it punishes people without acknowledging their ability to change. Don’t you think we may be overstepping that reasoning, if we assume that someone with the brain to be bad will continue to break the law?
Eagleman: I think it is right to repeal such a law – because people can change. One of the purposes of jail is to serve as punishment and the purpose of punishment is to rewire peoples’ brains and decision-making mechanisms. In the best scenario, jail changes people so that they don’t commit a crime again. That is one of the hopes of incarceration. Once somebody has served their sentence, we should allow for the case that they have changed. In Norway, in particular, they feel the same way, but with their preventive detention law, they say “Look, we believe somebody really is still dangerous to society”, which is to say he has not changed. This gives them the ability to sentence for another five years. But the point is that to very specifically try to assess whether a person has changed. They hope that the person has changed, but have a backup plan, just in case.

Mensel: How can neuroscience help make that decision?
Eagleman: Nowadays only very crudely. But 20 years from now, we might have some real resolution, some really fine tools to use in 20 years. But I want to emphasize one point: Sometimes people worry about the Minority Report situation, the “precrime” scenario. But that will never happen, not now, not it 21 years, not in 2100 years. Crime is too complicated, life is too complicated and crime is circumstantial. Meaning it’s got to be just the right mix between social fabric, the people you are with, the opportunities you got. Science would never be able to predict crime in particular, because is just way too complicated for that.

Mensel: I imagine that ongoing brain development complicates the picture…
Eagleman: At a later age, the brain no longer change at the same speed, but it does change. It it depends on what happens in your life, the experiences you have, the community you end up being with. Brains continue to change and the circumstances and opportunities around you continue to change. It is an equation with almost infinite variables, and that is why the whole “precrime” thing could never exist. Nonetheless, it is the case that some people really are more dangerous in general than other people, because of the way they make decisions. Their cost-benefit analysis is so different from other people that they tend to be more dangerous. And that is the sense in which we can look at someone like Breivik after 21 years: Is he still the kind of person who does not value human life and is very turned on by political ideologies? Nobody would be able to predict if he would commit any particular crime, but you can ask a question about his dangerousness.

Mensel: There is a test called the “psychopath test”, which is administered to crime suspects and includes all sorts of questions about their behavior, even at a younger age. Often this means that people are not released from prison, simply because they did something in their youth that wasn’t part of the crime they are in jail for.
Eagleman: Unfortunately it is the case that psychopaths tend to re-offend. If you have a normal brain and you end up in jail, that whole experience will be very punishing for you and help to change your brain so that you do not want to come back to jail. But psychopaths are very different: They do not learn from experience nor do the care about punishment. They also fundamentally do not care about other people. If they happen to be aggressive, than that is a very dangerous combination. Unfortunately, the way is stands now, there is no rehabilitative program for psychopaths. And as a result, if somebody is psychopathic – which might not be their fault – it makes them much more dangerous, like a rabid dog. Clearly, it is not fair, because it is not something they chose to be. But if it the point of the penal system is to keep dangerous people of the street, than that is what you have to do.

Mensel: I am concerned about what seems like a large grey area: There is really no way of knowing exactly what goes on inside of people, and so there is still a lot of speculation underlying that decision. You actually look at their brains, is there any physical evidence?
Eagleman: There is actually a lot of good neuroscience of psychopathy. From a psychological point of view, there have been studies for a long time, but in the last ten years, Neuroscience has studied it a lot as well. You can measure difference in the psychopathic brain versus the average brain, you can see major anatomical differences by the naked eye – at least on a group level. So there is real neuroscience behind this. It would be the same as asking: Who is more likely to be the playground bully? Would it be this giant overgrown child over here or this really skinny, tiny, short kid over there, with other heights in between? Even though it’s a grey area and the little kid could be a bully, it is still a pretty good guess about what the outcome is going to be. My analogy is not even as good as the real science, which is much better than what I am telling you. There are lot of things in life that are spectra, but that does not mean that they are not smart. People often ask: Isn’t it creepy to bring science into the courtroom? People get treated like statistics! But compared to what? What we have now is that pretty people get much short jail sentences than ugly people. If you are a psychopath that happens to be a pretty female, you can get away with anything. If you are a non-psychopathic, ugly male, you get thrown in jail! Every country has got their own form of racism going on. So it is not like the current system is perfect or fair. I think that by importing real data and making a legal system that is a lot more brain-compatible, we would be much better of than we are now.

This interview appeared in The European on August 10th, 2011.

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