A Destined Crime
When a murder occurs, people seek justice. They want that criminal put in jail (maybe even worse), and that’s that. However, not a lot of people are actually curious about why somebody would take another person’s life. Turns out, it has a lot to do with the human brain.
Obviously, committing such a serious crime is appalling, but a murderer’s brain is powerful. The human brain is coded for compassion, guilt, and empathy that causes the person inflicting harm to feel a degree of suffering that is in many ways as intense as what the victim is experiencing. The brute that commits these crimes have to overcome hefty neural wiring to do what they did. But the scary thing is, everybody is capable of ending someone else’s life. However, others are more predisposed to do so- even children.
The amygdala- the part of the brain that is involved in fear,aggression and social interactions- is implicated in crime. Dustin Pardini, PhD, of the University of Pittsburgh and his team found that 26-year-old men with lower amygdala volumes were three times more likely to be violent, aggressive, and show psychopathic traits three years later than men of the same age with more normal-sized amygdalas. This study was independent of factors including history of violence and social background. Other research also suggests that amygdala functioning, not just size, is more likely to be reduced among those with psychopathic tendencies.
At least one study indicates that such deficits may appear long before people commit crimes. Adrian Raine, DPhil, of the department of criminology at the University of Pennsylvania, led a study with Yu Gao, PhD, at CUNY-Brooklyn to examine fear conditioning, which is dependent on amygdala function. They conducted this experiment on a group of 1,795 three-year-olds whose fingers were equipped with electrodes. Simultaneously, the researchers were repeatedly playing two tones: one that was followed by a loud, unpleasant sound and another that was played alone. The difference in sweat responses to each tone by itself yielded a measurement of each toddler’s fear conditioning. Twenty years later, the team identified participants who had gone on to commit crimes and then compared them with noncriminal counterparts, matching them on gender, ethnicity and social adversity. They results showed that those children who went on to commit crimes had “simply failed” to demonstrate fear conditioning. In other words, they were not fearful when most people would be. The outcome of this experiment suggests that deficits in the amygdala, which are indirectly identifiable as early as age three, predispose people to crime at age twenty-three.
The anterior cingulate cortex (ACC) has also been linked to crime. The ACC plays a major role in impulsivity and behavior regulation. Psychologist Kent Kiehl, PhD, and colleagues at the University of New Mexico used fMRI (functional magnetic resonance imaging) to look at the brains of about 100 adult male inmates while they completed a cognitive task involving inhibitory control. It was discovered that prisoners with lower ACC activity were twice as likely to reoffend four years after they left prison than those with higher ACC activity (PNAS, 2013).
Psychologist Pascal Molenberghs of Monash University in Melbourne, Australia wanted to know more about what happens to your brain when you are killing someone else specifically. But because it would be illogical and unethical to ask a test subject to murder somebody just to see results, Molenberghs decided to recruit 48 subjects and asked them to submit to functional magnetic resonance imaging, which could scan their brains while they watched three different scenarios on video loops.
In one clip, a soldier would kill an enemy soldier. In the next, they would be killing a civilian. And in the last video, used as a control, the soldier would shoot a weapon without hitting anybody. In each case, the subject saw the scene from the shooter’s point of view. At the end of each loop, they were asked “Who did you shoot?” and were required to press one of three buttons on a keypad indicating solder, civilian, or no one- a way of making certain they were aware of what they had done. After the fMRI scans, they were also asked to rate on a scale of 1 to 7 how guilty they felt in each scenario.
Molenberghs knew that when he read the scans he would first focus on the activity in the orbitofrontal cortex (OFC), a region of the forebrain that has long been known to be involved with moral sensitivity, moral judgments, and making choices about how to behave. The nearby temporoparietal junction (TPJ) also bears some of this moral load. It processes the sense of agency- the act of doing something deliberately, and therefore owning the responsibility for it. However, that does not always make much of a difference in the real world. Whether a person deliberately shoots someone or the gun goes off accidentally, it would not matter because the victim would be dead regardless. On the other hand, it is significant in affecting how the criminal will later reckon with what they’ve done.
In the study, there was consistently greater activity in the lateral portion of the OFC when subjects imagined shooting civilians than when they shot soldiers. There was also more coinciding between the OFC and the TPJ- with the OFC effectively saying I feel guilty and the TPJ effectively answering You should. It was also found that the degree of OFC activation also correlated well with how bad the subjects reported they felt on their 1 to 7 scale, with more activity in the brains of the people who reported feeling greater guilt.
The OFC and TPJ shared moral processing with yet another region of the brain, known as the fusiform gyrus. This part of the brain was more active when subjects imagined themselves killing civilians- a telling finding since the fusiform gyrus is involved in analyzing faces, suggesting that the subjects were studying the expressions of their imaginary victims and, in doing so, humanized them. There was greater activity in a region named the lingual gyrus when subjects were killing soldiers. The lingual gyrus is involved in the much more dispassionate business of spatial reasoning- just the kind of thing you need when you’re going about the colder business of killing someone you feel justified killing.
Of course, soldiers and psychopaths are two different emotional species. But among people who kill criminally or promiscuously and those who kill legally, the same brain regions are surely involved, though may operate in different ways.
Now that researchers have a better understanding of the human brain when it comes to crime, what changes can be made in order to make sure violence doesn’t occur? Raine, the author of “The Anatomy of Violence,” says that intervention is the right way to go.
In one intervention, he and some colleagues discovered that 3-year-olds who had been assigned to an enrichment program focused on nutrition, exercise, and cognitive skills had better brain functioning at age eleven and a thirty-four percent reduction in criminal activity at age twenty-three when compared with a control group that did not receive this treatment (American Journal of Psychiatry, 2003). And not only is it important to help the children, but it is also equally beneficial when adults are helped out too. David Olds, PhD, of the University of Colorado has found that with intervening even earlier, pregnant low-income mothers who were visited regularly by home nurses that talked to them about health, education and parenting were less likely to have children who were arresting by age fifteen (Infant Mental Health Journal, 2006).
It’s clear that murder’s neural and moral roots are deeply entangled. However, learning to untangle these roots one day can be a big help for psychologists and criminologists to predict who will kill- and possibly stop them before they do.
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