Will testing the brain, even before birth, separate the good seeds from the bad?
When he was in his late 20s and living in his native England, Adrian Raine spent a lot of time locked in a van with violent criminals.
Raine worked at a maximum security prison in Hull, where his job involved attaching polygraph-type sensors to the prisoners’ skin to measure their agitation as he bothered them with loud sounds and flashes of light. His lab was in the back of a van, he says, “and the guards were very concerned these men would commandeer the vehicle and escape.”
Their solution? “Take my keys away and lock the doors from the outside.”
“So there I was, in this very tiny space,” recalls Raine, who is now in his 50s and is the chair of the criminology department at the University of Pennsylvania. “And I kept watching the needles these sensors were connected to, for I imagined that the first sign these men were about to rush me would be the needles starting to swing wildly as the men got excited and prepared to attack.”
They never did. And since then, Raine has never strayed far from the company of killers, wife batterers, and psychopaths—searching for clues to bad behavior or even criminal intent. Along with several other researchers, he has pioneered the science of neurodevelopmental criminology, which has established that among adult offenders, juvenile delinquents, and even younger children there are features in the brain that seem to reduce fear, impair decision making, and blunt emotional reactions to others’ distress.
While Raine was attending Oxford, he vacillated between wanting to be an experimental psychologist and wanting to teach primary school. As a result, he did some student teaching, which showed him that “there were some kids who were just bullies, very extreme, and I wondered, Why? Where did the behavior come from? Why were some kids angels and some devils?”
He made the topic into his doctoral research at the University of York, where he began using the lie detector–like sensors to measure heart rates and changes in the way the skin conducts electricity in teenagers with varying degrees of aggression.
After graduating, Raine began his work at Hull, where he did time with murderers, rapists, and pedophiles. “The main thing I learned was that I really can’t change these people,” he says. “It brought me back to kids, to earlier stages, thinking we’ve got to look at the earlier, predisposing factors, when maybe we can do something.”
Raine eventually broke out of jail and into academe, first at the University of Nottingham and then at the University of Southern California. One of his major lines of research was long-term studies of children, measuring physiological reactivity at young ages to see if any pattern related to bad behavior decades later.
Raine lucked into a major source of data. In the late 1960s, the World Health Organization had started to follow about 1,800 children on Mauritius, a small island nation in the Indian Ocean.
Over the years, Raine and several colleagues have shown that children from Mauritius who have slower heart rates and reduced skin responses when they are exposed to loud tones or challenging questions tend to run afoul of the law when they get older. In 1996 the researchers learned that 15-year-olds with this pattern tended to have criminal records by age 29. In 2010 the age was pushed back further: 3-year-olds who had similar physical responses were rated by teachers as more aggressive than other children five years later.
Normally, a startling noise races the heart and sends the body into a high state of alert, which is what the skin electrodes pick up. But there’s evidence that children who are not alarmed don’t react to the threat of punishment when they misbehave. Nor do they react to other people’s distress.
At Southern California, Raine was part of a team studying 605 families of twins. Some of the twins were identical, sharing 100 percent of their genes, and some were nonidentical, sharing 50 percent. When the children were ages 9 and 10, researchers gave them a battery of psychological tests to assess aggression and antisocial behavior. They also asked parents, teachers, and other children to rate the subjects’ antisocial tendencies. The results showed that these traits were more consistent in the identical pairs. “I think at least 50 percent of this can be attributed to genetics,” Raine says.
Raine then began wondering what blunted the senses. Was there something actually in the brains of these people that tied into this lack of fear, lack of sensitivity, and abundance of mayhem?
Others had wondered the same thing.
During the 1990s, Antonio R. Damasio, then a pioneering professor of neuroscience at the University of Iowa, focused on the amygdala, a small, almond-shaped area in the middle of the brain known to help process emotions. In patients with lesions in the region, he observed a repeated pattern of bad decisions, like making risky bets while they were gambling. Cut off from emotional reactions, these people lacked an alarm bell that signaled a poor choice. They could see many courses of action but, shorn of feedback from the amygdala, couldn’t tell good from bad. This extended to reading other people’s emotions, as well.
Damasio also found that damage to the prefrontal cortex, a brain area involved in decision making, could turn mild-mannered patients into rash, destructive individuals, seeming to rob them of a brake on their impulses. This led him to propose that the two regions normally link up to prevent people from harming others by generating emotional alarm (the amygdala) and acting on it (the prefrontal cortex). When either part of the chain is damaged, antisocial actions result. Damasio called this “acquired sociopathy.”
In 1997 Raine and several colleagues put the theory to the test on real killers. They compared the functioning of the brains of 41 convicted murderers with that of 41 normal people. Using positron emission tomography, or PET, a type of scan that measures the activity in areas of the brain, they saw lower activity in both the prefrontal cortex and the amygdala of the murderers’ brains.
When they further divided murderers into those who came from “good” homes and those who came from “bad” homes—those filled with neglect, abuse, and poverty—the first group showed lower activity in the prefrontal cortex, in particular an area called the orbitofrontal cortex. Raine’s interpretation: Genetics and anatomy were more influential on their development than was the way they grew up.
What’s more, a series of studies using magnetic resonance imaging, which reveals structures and shapes, showed that criminals and people who scored high on tests of antisocial disorders had a smaller than normal orbitofrontal region and amygdala. And the corpus callosum, the communications bridge between the brain’s two hemispheres, was abnormally large.
But those findings raised a chicken-and-egg-type question: Did the brain features produce the behavior, or did the behavior change the brain? Violent criminals are known to bang their heads into walls and abuse drugs, and both of those things damage the brain, possibly producing the shrinkage Raine was seeing on the brain scans. He needed to go back even further and look for a defect that begins before birth and can still be detected in adults. Raine found it in a hole in the head. More precisely, a thin wall of brain tissue that separates a hole—all brains have these spaces—into two. The hole appears during the 12th week of a fetus’s development, and the wall—pushed forward by a normally developing amygdala and other brain areas—divides it by the 20th week. When the wall doesn’t form completely, a condition known by the jawbreaking name of cavum septum pellucidum, it’s usually a sign of abnormal development in the amygdala and other structures. Years later, in adults, the failed wall can be spotted in a brain scan.
In a 2010 paper, Raine and his colleagues compared people with and without the feature on several fronts. The groups were tested for antisocial personality disorder, psychopathy, and aggression. Their records were searched for criminal arrests and convictions. In every single one of those areas, there were a lot more men and women with the wall defect. Here, finally, was evidence tracing criminality back to the womb, before any head-banging could occur.
“I think there’s no longer any question, scientifically, that there’s an association between the brain and criminal behavior. We’re beyond the point of debating that,” says Raine. “Every study can be criticized on methodology. But when you look at the whole, at all the different designs, it’s just hard to deny there is something going on with biology.”
So what do we do now?
One thing we don’t do, says Nathalie M.G. Fontaine, an assistant professor of criminology at Indiana University at Bloomington, is mark children as future criminals. “I would never put a risk number on a specific child,” says Fontaine, who has studied callousness among children as a predictor of bad behavior. “We are talking about groups, not individuals. We don’t know what will happen with any one child, because there are also protective factors.” A strongly supportive family, or an influential schoolteacher, or religion could blunt the effects of a hole in the head on the plastic, changeable brain.
Raine is a big believer in protective factors. “You can’t make a lesion to the prefrontal cortex and, hey presto, you get a criminal. It’s not like that,” he says. “Of course social factors are critically important.” In his current study of Philadelphia children with the slow physical reactivity that has been linked to trouble, some are getting a diet rich in omega-3 fatty acids and calcium to see if they protect brain cells, some are getting cognitive-behavioral therapy, and some are getting both to see if trouble can be staved off.
Still, the time is coming, Raine believes, when putting numbers on children will be tempting. If a 75 percent chance of a bad seed isn’t high enough, he wonders, what about 80 percent? Or 95? “Look, I have two children, 9-year-old nonidentical twin boys,” he says. “And I’d definitely want to know, especially if there was a treatment that has a chance of success. But I realize not every parent will. We have to start having this conversation now, though, so we understand the risks and the benefits. It’s easy to get on your moral high horse about stigma and civil liberties, but are you going to have blood on your hands in the future because you’ve blocked an approach that could lead to lives being saved?”
Josh Fischman is a senior editor at The Chronicle Review. Excerpted from The Chronicle Review, an award-winning weekly newspaper for college and university faculty members, administrators, and students. www.chronicle.com