Incognito (24 page)

The night before Whitman had sat at his typewriter and composed a suicide note:

As news of the shooting spread, all Austin police officers were ordered to the campus. After several hours, three officers and a quickly deputized citizen worked their way up the stairs and
managed to kill Whitman on the deck. Not including Whitman, thirteen people were killed and thirty-three wounded.

The story of Whitman’s rampage dominated national headlines the next day. And when police went to investigate his home for clues, the story became even more grim: in the early hours of the morning before the shooting, he had murdered his mother and stabbed his wife to death in her sleep. After these first killings, he had returned to his suicide note, now writing by hand.

Along with the shock of the murders lay another, more hidden surprise: the juxtaposition of his aberrant actions and his unremarkable personal life. Whitman was a former Eagle Scout and marine, worked as a teller in a bank, and volunteered as a scoutmaster for Austin Scout Troop 5. As a child he’d scored 138 on the Stanford Binet IQ test, placing him in the top 0.1 percentile. So after he launched his bloody, indiscriminate shooting from the University of Texas Tower, everyone wanted answers.

For that matter, so did Whitman. He requested in his suicide note that an autopsy be performed to determine if something had changed in his brain—because he suspected it had. A few months before the shooting, Whitman had written in his diary:

Whitman’s body was taken to the morgue, his skull was put under the bone saw, and the medical examiner lifted the brain from its
vault. He discovered that Whitman’s brain harbored a tumor about the diameter of a nickel. This tumor, called a glioblastoma, had blossomed from beneath a structure called the thalamus, impinged on the hypothalamus, and compressed a third region, called the
amygdala.
²
The amygdala is involved in emotional regulation, especially as regards fear and aggression. By the late 1800s, researchers had discovered that damage to the amygdala caused emotional and social disturbances.
³
In the 1930s, biologists Heinrich Klüver and
Paul Bucy demonstrated that damage to the amygdala in monkeys led to a constellation of symptoms including lack of fear, blunting of emotion, and overreaction.
⁴
Female monkeys with amygdala damage showed inappropriate maternal behavior, often neglecting or physically abusing their infants.
⁵
In normal humans, activity in the amygdala increases when people are shown threatening faces, are put into frightening situations, or experience social phobias.

Whitman’s intuition about himself—that something in his brain was changing his behavior—was spot-on.

Others had noticed the changes as well.
Elaine Fuess, a close friend of Whitman’s, observed, “Even when he looked perfectly normal, he gave you the feeling of trying to control something in himself.” Presumably, that “something” was his collection of angry, aggressive zombie programs. His cooler, rational parties were battling his reactive, violent parties, but damage from the tumor tipped the vote so it was no longer a fair fight.

Does the discovery of Whitman’s brain tumor modify your feelings about his senseless murdering? If Whitman had survived that day, would it adjust the sentencing you would consider appropriate
for him? Does the tumor change the degree to which you consider it “his fault”? Couldn’t you just as easily be unlucky enough to develop a tumor and lose control of your behavior?

On the other hand, wouldn’t it be dangerous to conclude that people with a tumor are somehow free of guilt, or that they should be let off the hook for their crimes?

The man on the tower with the mass in his brain gets us right into the heart of the question of blameworthiness. To put it in the legal argot: was he
culpable
? To what extent is someone at fault if his brain is
damaged in ways about which he has no choice? After all, we are not independent of our biology, right?

Whitman’s case is not isolated. At the interface between neuroscience and law, cases involving brain damage crop up increasingly often. As we develop better technologies for probing the brain, we detect more problems.

Take the case of a forty-year-old man we’ll call Alex. Alex’s wife, Julia, began to notice a change in his sexual preferences. For the first time in the two decades she had known him, he began to show an interest in child pornography. And not just a little interest, an overwhelming one. He poured his time and energy into visiting child pornography websites and collecting magazines. He also solicited prostitution from a young woman at a massage parlor, something he had never previously done. This was no longer the man Julia had married, and she was alarmed by the change in his behavior. At the same time, Alex was complaining of worsening headaches. And so Julia took him to the family doctor, who referred them on to a neurologist. Alex underwent a brain scan, which revealed a massive brain tumor in his
orbitofrontal cortex.
⁶
The neurosurgeons removed the tumor. Alex’s sexual appetite returned to normal.

Alex’s story highlights a deep central point: when your biology changes, so can your decision making, your appetites, and your desires. The drives you take for granted (“I’m a hetero/homosexual,” “I’m attracted to children/adults,” “I’m aggressive/not aggressive,” and so on) depend on the intricate details of your neural machinery. Although acting on such drives is popularly thought to be a free choice, the most cursory examination of the evidence demonstrates the limits of that assumption; we will see further examples in a moment.

The lesson of Alex’s story is reinforced by its unexpected follow-up. About six months after the brain surgery, his pedophilic behavior began to return. His wife took him back to the doctors. The neuroradiologist discovered that a portion of the tumor had been missed in the surgery and was regrowing—and Alex went back under the knife. After the removal of the remaining tumor, his behavior returned to normal.

Alex’s sudden pedophilia illustrates that hidden drives and desires can lurk undetected behind the neural machinery of socialization. When the frontal lobe is compromised, people become “disinhibited,” unmasking the presence of the seedier elements in the neural democracy. Would it be correct to say that Alex was “fundamentally” a pedophile, merely socialized to resist his impulses? Perhaps, but before we assign labels, consider that you probably would not want to discover the alien subroutines that lurk under your own frontal cortex.

A common example of this
disinhibited behavior is seen in patients with
frontotemporal dementia, a tragic disease in which the frontal and temporal lobes degenerate. With the loss of the brain tissue, patients lose the ability to control the hidden impulses. To the frustration of their loved ones, these patients unearth an endless variety of ways to violate social norms: shoplifting in front of store managers, removing their clothes in public, running stop signs, breaking out in song at inappropriate times, eating food scraps found in public trash cans, or being physically aggressive or sexually transgressive. Patients with frontotemporal dementia commonly end up in courtrooms, where their lawyers, doctors,
and embarrassed adult children must explain to the judge that the violation was not the perpetrator’s
fault
, exactly: much of their brains had degenerated, and there is currently no medication to stop it. Fifty-seven percent of frontotemporal dementia patients display socially violating behavior that sets them up for trouble with the law, as compared to only 7 percent of Alzheimer’s patients.
⁷

For another example of changes in the brain leading to changes in behavior, consider what has happened in the treatment of
Parkinson’s disease. In 2001, families and caretakers of Parkinson’s patients began to notice something strange. When patients were given a drug called
pramipexole, some of them turned into gamblers.
⁸
And not just casual gamblers—pathological gamblers. These were patients who had never before displayed gambling behavior, and now they were flying off to Vegas. One sixty-eight-year-old man amassed losses of over $200,000 in six months at a series of casinos. Some patients became consumed with internet poker, racking up unpayable credit card bills. Many did what they could to hide the losses from their families. For some, the new addiction reached beyond gambling to compulsive eating, alcohol consumption, and hypersexuality.

What was going on? You may have seen the awful plunder of Parkinson’s, a degenerative disorder in which the hands tremble, the limbs become stiff, facial expressions turn blank, and the patient’s balance progressively worsens. Parkinson’s results from the loss of cells in the brain that produce a neurotransmitter known as dopamine. The treatment for Parkinson’s is to increase the patients’ dopamine levels—usually by increasing the body’s production of the chemical, and sometimes by using medications that directly bind to dopamine receptors. But it turns out that dopamine is a chemical on double duty in the brain. Along with its role in motor commands, it also serves as the main messenger in the reward systems, guiding a person toward food, drink, mates, and all things useful for survival. Because of its role in the reward system, imbalances in dopamine can trigger gambling, overeating, and drug addiction—behaviors that result from a reward system gone awry.
⁹

Physicians now watch out for these behavioral changes as a
possible side effect of dopamine drugs like pramipexole, and a warning is clearly listed on the label. When a gambling situation crops up, families and caretakers are instructed to secure the credit cards of the patient and carefully monitor their online activities and local trips. Luckily, the effects of the drug are reversible—the physician simply lowers the dosage of the drug and the compulsive gambling goes away.

The lesson is clear: a slight change in the balance of brain chemistry can cause large changes in behavior. The behavior of the patient cannot be separated from his biology. If we like to believe that people make free choices about their behavior (as in, “I don’t gamble because I’m strong-willed”), cases like Alex the pedophile, the frontotemporal shoplifters, and the gambling Parkinson’s patients may encourage us to examine our views more carefully. Perhaps not everyone is equally “free” to make socially appropriate choices.

Many of us like to believe that all adults possess the same capacity to make sound choices. It’s a nice idea, but it’s wrong. People’s brains can be vastly different—influenced not only by genetics but by the environments in which they grew up. Many “pathogens” (both chemical and behavioral) can influence how you turn out; these include substance abuse by a mother during pregnancy, maternal stress, and low birth weight. As a child grows, neglect, physical abuse, and head injury can cause problems in mental development. Once the child is grown, substance abuse and exposure to a variety of toxins can damage the brain, modifying intelligence, aggression, and decision-making abilities.
¹⁰
The major public health movement to remove lead-based paint grew out of an understanding that even low levels of lead can cause brain damage that makes children less intelligent and, in some cases, more impulsive and aggressive. How you turn out depends on where you’ve been. So when it comes to thinking
about blameworthiness, the first difficulty to consider is that people do not choose their own developmental path.

As we’ll see, this understanding does not get criminals off the hook, but it’s important to lead off this discussion with a clear understanding that people have very different starting points. It is problematic to imagine yourself in the shoes of a criminal and conclude, “Well,
I
wouldn’t have done that”—because if you weren’t exposed to
in utero
cocaine, lead poisoning, or physical abuse, and he was, then you and he are not directly comparable. Your brains are different; you don’t fit in his shoes. Even if you would like to imagine what it’s like to be him, you won’t be very good at it.

Who you even have the possibility to be starts well before your childhood—it starts at conception. If you think genes don’t matter for how people behave, consider this amazing fact: if you are a carrier of a particular set of genes, your probability of committing a violent crime goes up by eight hundred and eighty-two
percent
. Here are statistics from the U.S. Department of Justice, which I’ve broken down into two groups: crimes committed by the population that carries this specific set of genes and by the population that does not: