law and Neuropsychology

Wired.com: You argue that brain science could improve our legal system. How would that work?

Eagleman: As part of my day job I direct the Initiative on Neuroscience and Law. What I’m asking is, given the situation that much of what we do and think and act and believe is all generated by parts of our brain that we have no access to, what does this mean when we think about responsibility and blameworthiness when people are bad actors in society?

I’ve been working on this topic for years and it’s become clear to me that our legal system as it stands now is so broken and outdated. It essentially rests on this myth of equality, which says all brains are created equal. As long as you’re over 18 and you’re over an IQ of 70, then all brains are treated as though they have an equal capacity for decision making, for simulating possible futures for understanding consequences and so on. And it’s simply not true.

Along any axis that we measure brains, they are very different. There’s as much variation neurally as there is with people’s external physical characteristics. So an enlightened legal system, and one that’s also more humane and more cost effective, will instead of treating everybody equally and treating incarceration as a one-size-fits-all solution, will do customized sentencing and customized rehabilitation. It will try to understand people better, in terms of what can be done with them and for them. It can have better risk assessment to understand, “How dangerous is this person?”

We still have to take people who break the law off the streets to have a good society, so this doesn’t forgive anybody. But what it means is we have a forward-looking legal system that just worries about the probability of recidivism, or in other words, what is the probability that this person’s behavior will transfer to other future situations? That makes a forward-looking legal system instead of a backward-looking one like we have now, which is just a matter of blame and saying, “How blameworthy are you and we’re going to punish you for that.”

What’s happening more and more in courtrooms is defense lawyers will argue that their client has bad genes, that he was sexually abused as a child or he had in utero cocaine poisoning, so it wasn’t really his fault. It turns out that’s the wrong question to ask, because the interaction of genes and environment is so complex that we will never be able to say how somebody came to be who he is now and whether he had any real choice in the matter of whether he behaved this way or that way. So the only logical thing is to have a forward-looking system that says, “We can’t know the answer to that, all we need to know is how dangerous is this person into the future?”

Beyond that there’s this issue that our prison system has become our de facto mental health care system. The estimates now are that 30 percent of the prison population suffers from some sort of mental illness. It’s much more humane and enlightened and cost effective to have a system that deals with the mentally ill separately, deals with drug addicts separately. and so on. Incarceration is the right solution for some people because it will be a deterrent. But it doesn’t work if your brain’s not functioning properly. If you’re suffering from a psychosis, for example, putting you in prison isn’t going to fix that.

Wired.com: So do we need, next to the jury of your peers, a jury of brain experts?

Eagleman: So here’s what I think. Trials have two phases. There’s the guilt phase, or the fact finding phase, and of course that should always remain with a jury of your peers, there are many reasons for that. But the sentencing phase should be done with statistics and sophisticated risk assessment instruments. And I should mention, these are already underway.

For example, with sex offenders, people have done very good studies where they have followed tens of thousands of sex offenders for years after they are released form prison, and they find out who recidivates and who doesn’t. Then they correlate that with all of these things they can measure about the person. And it turns out that that gives really good predictive power about who’s likely to recidivate and who’s not.

Now I need to specify here that we will never be able to know whether any individual will commit a crime again or not, because life’s too complicated and crime is often circumstantial. Nonetheless, it is the case that some people are more dangerous than others. And these statistical tests are incredibly powerful tools for understanding who on average is going to be more dangerous than whom and thereby how long we should sentence them for.