The Anatomy of Violence (27 page)

Men, of course, were found to be more antisocial and criminal than women, replicating a worldwide finding. No big deal. But what if we look again at this sex difference in crime, this time controlling for the sex difference in ventral gray volume? If we make men and women statistically the same in terms of their ventral volume, we cut the sex difference in crime by 77 percent.
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So more than half of the reason men
and women differ in crime seems to be because their
brains are physically different.

I’m not saying that all the difference in crime between men and women can be put down to the brain. And I’m certainly not saying that we should ignore differences in socialization and other social and parenting influences. But what I am arguing is that there are fundamental neurobiological differences between men and women that can help explain the gender difference in crime. It’s also striking that we find sex differences in the very same frontal sectors that are linked to antisocial behavior—men and women did not differ in prefrontal sectors that are not related to crime.

These findings do not come out of the blue. Sex differences in prefrontal gray have been documented in several other
MRI studies. One imaging study found a 16.7 percent reduction in orbitofrontal volumes in men compared with women.
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Three other studies have found this same sex difference,
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including one large study of 465 normal adults.
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Men have also been reported to show lower activation of the orbito
frontal cortex compared with women when performing a wide variety of cognitive and emotional tasks, including
verbal fluency,
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working
memory,
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processing
threat stimuli,
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and working memory during a negative emotional context.
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Men simply have different brains from women, and it’s pointless to cover up and ignore these fundamental sex differences.

The position so far looks like this: We’ve seen that offenders have
structural impairment to the prefrontal cortex. We’ve also seen that they have poor functioning of this same brain region. We documented in a meta-analysis of forty-three brain-imaging studies of offenders involving 1,262 subjects that these structural and
functional prefrontal deficits are replicable findings.
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The structural prefrontal impairment partly explains the sex difference in crime. It’s hard to escape from the conclusion that impairment to this brain region—through either environmental or genetic causes or both—predisposes some to an antisocial, disinhibited, impulsive lifestyle.

But before moving on, let’s underscore an important fact: no proposed cause of offending—whether it be social or neurobiological—inevitably results in crime and
violence. While the dramatic case of
Phineas Gage from Vermont in 1848 originally set up the prefrontal dysfunction theory of psychopathic and antisocial behavior, three more clinical cases strike a chord of caution lest we take this theory too far.

The first is the remarkable case of an individual known as the Spanish Phineas Gage—referred to here as SPG—a twenty-one-year-old university student living in Barcelona. It was 1937, the
Spanish Civil War was raging, and nobody was safe. One fateful day he found himself upstairs in a house being pursued by the opposition in this civil struggle. Almost cornered, he threw open the window, climbed out onto the windowsill, and made a bold attempt to escape by shinnying down the drainpipe on the outside wall.

Unfortunately for SPG, the pipe was old, and it broke away from the wall. SPG clung on to it for dear life, falling down onto a spiked metal gate. His
head was impaled on the gate, with a spiked point entering the left side of his forehead, injuring his left eyeball, and coming out through the right side of his forehead. It selectively damaged his prefrontal cortex, just as the metal tamping rod had blasted a discrete hole through Phineas Gage’s
brain.

People came to the rescue. They were able to cut through the bar, with SPG conscious all the time throughout the ordeal. He even helped his rescuers to get him off the gate. As with Gage they quickly got him to medical care, delivering him to the Hospital de la Santa Creu i Sant Pau in Barcelona.
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The damage to his prefrontal cortex was quite extensive, and, just like Gage, he lost vision in his left eye. Again like Gage he survived the horrific accident, and it was not long before he was back on his feet, creating a new life for himself. And yet again it truly was a new life. Just like Gage, he was impatient, restless, impulsive, and would move from one thing to another, unable to properly finish any single task.

Yet here the striking parallel ends between the American and the Spanish Phineas Gages. Despite having the usual
executive dysfunction that one expects from such a
head injury, and despite his impulsivity, SPG did not develop the antisocial, psychopathic personality that characterized Gage. Why not?

The answer once again lies at least in part in the environment. At the time of the accident, he was engaged to his childhood sweetheart.
As they once said in Rome,
amore vincit omnia
—
love conquers all. And over in Barcelona love helped conquer the antisocial sequelae that we might normally have expected from this dreadful prefrontal damage. SPG’s sweetheart stood by him, and three years after the horrific accident, they were married. Unlike Gage, SPG had spousal support, and his support system did not end there. For the rest of his life he was able to hold down a steady job in one location, unlike Gage, who drifted around for a significant period of his life.

How could this be possible, you may say. You are by now becoming an adroit neuropsychologist, and you know that prefrontal damage invariably leads to the inability to sustain
attention, to complete a task, to shift strategies in tackling problems, and to plan ahead. This was indeed true of SPG, who showed significant impairments on
frontal-lobe executive tasks. But the environment is again the answer. His parents were wealthy and owned a family firm where SPG was employed for the rest of his life. His poor
executive functioning meant that he was never a particularly good worker. He could do only basic manual tasks and always had to be closely supervised and checked. Yet a job it was, and with it came security and occupational functioning.

Lady Luck was not finished with SPG. He not only had a devoted wife and caring, affluent parents to support him, but he also went on to have two loving children who were destined to play a role in his psychosocial rehabilitation. In the words of his daughter:

SPG could hold his broken head high throughout his life. He was always able to bring home the bacon after his hard day’s work. He had occupational functioning. He had family functioning. He had love in his life from all quarters. As many of you likely know if you reflect on episodes in your own lives, love truly can overcome enormous adversity. For me this case highlights the critical importance of psychosocial protective factors that can guard against a life of crime in the face of horrendous prefrontal damage.

As with Gage, we see in SPG a man who was not antisocial before the accident that caused the prefrontal damage. Let’s now turn to our
second chord of caution, but here our case was
antisocial
before
the head injury.

This second case study dates from approximately 2000 and concerns a thirteen-year-old-boy from Utah who by all accounts was a bit of a Johnny-gone-rotten.
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For most of his short life, he had been rotten to the core, with a well-documented history of
conduct disorder,
risk-taking,
hyperactivity, and
attention-deficit disorder. Sadly, his parents had long since lost their parental
rights, and he lived in a foster home. He was a bad kid, but bear in mind that genes and an early negative home environment likely worked against him to make him what he was.

One day the lonely lad was playing Russian roulette by himself with a .22-caliber pistol. After all, despite the natural beauty of the state, what else is there for a hyperactive, stimulation-seeking, conduct-disordered boy to do in Utah? With the pistol perched underneath his chin and the barrel pointing straight up, he pulled the trigger. The loaded chamber turned, the wheel of fortune spun, and the pistol went off. He succeeded in punching a hole right through his prefrontal cortex.

Again our case was rushed to the hospital. Yet again he miraculously survived his deadly game. The
CT scan taken soon after he arrived at the hospital showed that the bullet had punched a neat hole through his brain, selectively damaging the very middle part of his prefrontal cortex in much the same way that Phineas Gage’s medial prefrontal cortex was damaged by the tamping rod. If he had wanted to selectively take out this very midline part of the medial prefrontal cortex, frankly, the poor youngster could not have done a better job.

The really unusual aspect of this case is, well, nothing. I mean, nothing really unusual happened afterward. Despite losing at Russian roulette, the boy did not have such a bad ending. His social workers, foster parents, psychologist, and all legal authorities who had been managing his case agreed that he was completely unchanged by the brain damage. He was the same unruly, conduct-disordered urchin that he always had been. But he was not worse. He did not even show any additional cognitive deficits.

As the Americans say, “What gives?” The neuropsychologist
Erin
Bigler, who reported this case, reasoned that the young teenager had succeeded in knocking out only the piece of his medial prefrontal cortex that was
already
dysfunctional, the part that had been causing the conduct disorder in the first place. This second case study highlights a truism—that prefrontal damage does not by any means always result in behavioral change in the antisocial direction, particularly if, unlike the American and
Spanish Phineas Gage cases, the individual was not normal to begin with.

Our third case takes this principle to another level. It underscores the point that there can be marked differences in outcome when prefrontal damage strikes. It is yet another Gage-like accident, and, as with the Utah Russian-roulette case, we are dealing with an individual with a deeply entrenched preexisting antisocial condition. But on this occasion there is an astonishing change in behavior after the accident.

This chord of caution deals with a thirty-three-year-old man from Philadelphia who had a history replete with antisocial and aggressive behavior throughout his life—a life-course persistent offender who was pathologically aggressive. He was also
depressed. In fact, he was very depressed. He decided to end his life—but in an unusual way. He took a crossbow and—in a manner remarkably reminiscent of the Russian-roulette case—he placed the bow underneath his chin, with the arrow bolt pointing straight up, and he released the trigger.

Like a tamping rod, the bolt shot right up into his prefrontal cortex, and as was the case with the Spanish Phineas Gage, the deadly projectile lodged firmly in his brain. Like the other victims we have witnessed, he was rapidly rushed to medical care. Yet again it’s a strange survival story. This unhappy and deeply troubled man was taken to my university hospital—the
Hospital of the University of Pennsylvania—to have the bolt extracted from his brain. It selectively damaged the medial prefrontal cortex, just as it had been with Gage and our Russian-roulette case. The missiles in all three cases had essentially the same trajectory, entering from the lower part of the head and exiting from the top of the front part of the skull.

There was a new twist in this case. As with Gage, the Philadelphian Crossbow Man was radically changed by the prefrontal damage—but in the opposite direction. Gage had been transformed from a normal
man into a psychopathic-like individual. The Philadelphia Crossbow Man was instead transformed from an aggressive, irritable, emotionally labile antisocial into a quiet, docile, and content man.

The pathological aggression was eradicated overnight. The depression disappeared in a jiffy. It was a miracle cure. Indeed, the only neuropsychiatric symptom that resulted from the damage to a man who had been seriously depressed was that, in the words of his clinician, he became “inappropriately cheerful.”
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He simply cheered up.

This third case study again reveals the complexity of the relationship between
brain and behavior, and highlights the striking differences in outcome that can occur as a function of damage to the pre
frontal cortex. In the crossbow case, the fact that this disturbed and depressed individual became jolly after the accident is not entirely surprising.
Puerile jocularity is one neurological symptom of damage to the prefrontal cortex, and this is what we see here. Indeed, puerile jocularity also characterized the
Spanish Phineas Gage. Apparently, he spent a lot of time telling the same old lame jokes and being overly cheerful.
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So when at your next work party you meet that disinhibited, loquacious extravert who tells bad jokes and laughs at them like there is no tomorrow, make a neurological note to yourself and suspect either a spiked bar, a crossbow bolt—or perhaps just plain old frontal-lobe dysfunction.

Clearly we must be cautious with our prefrontal cortical explanation of crime. Prefrontal damage doesn’t always produce antisocial behavior. But let us not forget that overall there is a link between prefrontal structure and violence based on
MRI and neurological studies, so we have to be equally cautious not to discount the hypothesis that prefrontal brain damage causes violence.