People from all across the political spectrum have their problems with Adrian Raine.

From the left, Raine hears complaints that his research connecting brain dysfunction to crime—work that hints at the possibility of one day being able to identify potential criminals early in life—could infringe upon civil liberties. From the right, he is scolded for even suggesting that some violent offenders may not be able to control their actions. Even some of Raine’s colleagues consider the research dangerous.

Raine understands all of the complaints and worry. But he also says he must continue. Besides, he says, unless we can understand what causes people to become violent criminals, we’ll be stuck with crime forever.

“If we ignore the brain and genetic basis for crime, we’ll never stop it,” says Raine, a neurologist and psychologist who came to Penn in early 2007 as the fourth Penn Integrates Knowledge professor. “In the future, we’ll just be living out the same headlines that we’re living with today—murder, rape, arson, the whole thing. Do we really want that? Or are we going to act?”

Q. How would you describe your work?
A. I study the biological basis of crime and violence. I study this in both children and adults. We’re trying to work out, for instance, what causes these young children to grow up and become criminals. You have little innocent children, out playing in the playground, and some of them just grow up to be psychopaths. So the question is, what transforms this mild-mannered little child into this evil terror? That’s the question I’m trying to answer.
Starting early in life, we have seen some evidence that criminals are created early in development. Some work has been conducted on birth complications, and how when you combine birth complications with a mother rejecting a child in the first year of life, that can contribute to an individual becoming a violent offender later in life. But there is no destiny here. It’s not the case that these kids who take the double hit of complications and rejection will definitely become a violent criminal. It’s really a very complex puzzle made up of many different pieces, and we’re just starting to turn over these pieces of the puzzle. Part of it is about child abuse. Part of it is about prefrontal brain dysfunction, part of it is low physiological arousal. That’s where we’re at now.

Q. Can you describe some of the research you’ve done in relation to children?
A. One study we’ve been doing is on the island of Maurisus. We’ve been following 1,800 children there since the age of three, and trying to figure out what early factors might shape antisocial behaviors. For instance, we’ve found that children who have a fearless temperament at age three, and those that are stimulation seekers at age three, they become more aggressive later in life. The idea is that if you’re lacking in fear, then you don’t mind getting in a fight, or having your nose broken, because you lack fear. It’s that fear that stops the rest of us from going out and robbing the bank or the 7-Eleven. Meanwhile, some of our newer research has shown that those with low-resting heart rates are also more likely to be aggressive. That’s because if you have low physiological arousal, you may seek out situations to get that arousal level up to normal—maybe join a gang, rob a store, beat somebody up.

Q. How does this all tie in to your brain-imaging work?
A. Well, I haven’t touched on the brain yet, but I wanted to discuss one more thing, because it ties into that. We’ve always known that kids with poor nutrition are more likely to be aggressive and antisocial, and that’s at ages 8, 11 and 17. But poor nutrition is going to actually affect the brain structure and brain function, and that fits into our model, which is that poor brain function predisposes people to antisocial behavior.

Q. How long have you been working to make this connection?
A. Over 20 years. What we’ve been able to find out is a number of things showing that some people who are repeat violent offenders—your violent criminal—have a structural impairment of the prefrontal cortex. Their brains are literally physically different than ours. They have an 11 percent reduction in gray matter in the prefrontal cortex, which is the part of the brain that … sits just above the eyes and just behind the forehead. It’s the part of the brain that is involved with regulation and control of behavior. But where does aggression come from? From the deeper part of the brain, the limbic system for instance, which gives rise to aggressive feelings. This prefrontal cortex is there to regulate these deeper and more primitive parts of the brain. It sort of acts as a guardian angel for behavior. We all get angry. We all get fuming mad. But we don’t all lash out, because of the prefrontal cortex. It says to us, ‘Don’t do this.’ But if that prefrontal cortex is damaged functionally or physically, the emergency break, if you will, is not there to be turned on. That can give rise to unbridled violent behavior.

Q. How do you see that damage or dysfunction in a brain scan?
A. Well, for example, we recently studied 41 murderers and compared their [scans] to 41 control subjects. Now the prefrontal cortex is the part of the brain that regulates emotions and informs decision-making. Criminals are bad decision makers. Think about it: People go into prison and it’s like a revolving door, because they go right back in. They’re just bad decision makers. We used the brain scans to look at glucose metabolism in the prefrontal cortex. And we’ve found that murderers as a group have a significant reduction in glucose metabolism there. But then we also [scanned] a man who killed 64 people over a 12-year period. He was a pretty successful serial killer, and was actually somewhat unlucky to be caught—he got pulled over for a traffic violation at night on the freeway and police got suspicious when there was a dead body in the passenger seat. If not for that, he would likely still be killing now. But when we looked at his brain, it didn’t look like the brains of the one-off killers. In fact, he had good activity in his prefrontal cortex. To me, that’s the exception that proves the rule, because he had to carefully plan his kills over a 12-year-period. He had to carefully cover his tracks. You need good functioning in the prefrontal cortex for that. Then we also have here another individual whose brain scan looks very much like that of the serial killer. And what’s interesting here is that it’s my brain scan [laughs]. So the point I want to make is that, of course, brain scans are not exactly a diagnostic tool. You can have normal people like myself who have brain function like this or you can have murderers who have quite normal brain function. Environment is important too.

Q. In what ways?
A. Well, the way the brain sits in the skull, there is a sort of bony protrusion in the front. And if you were, for example, shaken vigorously as an infant, that prefrontal cortex could become bruised and lead to impairments.

Q. So it’s like you said—there are many pieces to this puzzle.
A. Absolutely. And now the other work we’re getting involved in is related to moral decision making. … The question becomes, is one of the reasons that people commit crime because the moral circuitry [in their brain] is dysfunctional? These people break the rules. They don’t care about other people. But is their fundamental moral decision-making gone awry? That leads then into a lot of even more complex issues that effect the judicial system and neuroethics. Such as, if somebody has a brain dysfunction that causes antisocial behavior, to what extent can we punish them? Is there truly free will for 100 percent of all people? Or is there, for some, some constraints? Are they fully responsible for their actions in the same way as you or I? Is it morally right of us to be punishing them and executing them as we do?

Q. I can see, obviously, how this all becomes political.
A. It’s a bit of a minefield. But I do believe there is a brain basis for crime. I equally believe that there is a social and environmental basis, both of which are equally important. So that’s the intellectual challenge—to work out how all of these factors come together and interact to create the violent offender.

Q. I assume there are those who would rather you not do this work.
A. Yes. I would bet the majority of the people of the field I’m in, which is criminology, believe there is not a brain basis for crime. There are serious and well-respected people who would say no good could ever come of probing the genetic basis for crime. ... So one of the goals I have is to convince more people in my discipline that there is a genuine and significant brain and genetic basis for crime. We can be ostriches with our heads in the sand, but if we do that, you know what? The ostrich is going to be shot.

Originally published March 27, 2008