How We Decide (23 page)

This is the danger of too much information: it can actually interfere with understanding. When the prefrontal cortex is overwhelmed, a person can no longer make sense of the situation. Correlation is confused with causation, and people make theories out of coincidences. They latch on to medical explanations, even when the explanations don't make very much sense. MRIs make it easy for doctors to see all sorts of disc "problems," and so they reasonably conclude that these structural abnormalities are causing the pain. They're usually wrong.

Medical experts are now encouraging doctors
not
to order MRIs when evaluating back pain. A recent report in the
New England Journal of Medicine
concluded that MRIs should be used to image the back only under specific clinical circumstances, such as when doctors are examining "patients for whom there is a strong clinical suggestion of underlying infection, cancer, or persistent neurologic deficit." In the latest clinical guidelines issued by the American College of Physicians and the American Pain Society, doctors were "strongly recommended ... not to obtain imaging or other diagnostic tests in patients with nonspecific low back pain." In too many cases, the expensive tests proved worse than useless. All of the extra detail just got in the way. The doctors performed better with less information.

And yet, despite these clear medical recommendations, MRIs continue to be routinely prescribed by physicians trying to diagnose causes of back pain. The addiction to information can be hard to break. A 2003 report in
JAMA
found that even when doctors were aware of medical studies criticizing the use of MRI, they still believed that imaging was necessary for their own patients. They wanted to find a
reason
for the pain so that the suffering could be given a clear anatomical cause, which could then be fixed with surgery. It didn't seem to matter that these reasons weren't empirically valid, or that the disc problems seen by MRI machines don't actually cause most cases of lower back pain. More data was seen as an unqualified good. The doctors thought it would be irresponsible not to conduct all of the relevant diagnostic tests. After all, wasn't that the rational thing to do? And shouldn't doctors always try to make rational decisions?

The problem of diagnosing the origins of back pain is really just another version of the strawberry-jam problem. In both cases, the rational methods of decision-making cause mistakes. Sometimes, more information and analysis can actually constrict thinking, making people understand less about what's really going on. Instead of focusing on the most pertinent variable—the percentage of patients who get better and experience less pain—doctors got sidetracked by the irrelevant MRI pictures.

When it comes to treating back pain, this wrong-headed approach comes with serious costs. "What's going on now is a disgrace," says Dr. John Sarno, a professor of clinical rehabilitation at New York University Medical Center. "You have well-meaning doctors making structural diagnoses despite a serious lack of evidence that these abnormalities are really causing the chronic pain. But they have these MRI pictures and the pictures seem so convincing. It's amazing how perfectly intelligent people will make foolish decisions if you give them lots of irrelevant stuff to consider."

The powers of the Platonic charioteer are fragile. The pre-frontal cortex is a magnificent evolutionary development, but it must be used carefully. It can monitor thoughts and help evaluate emotions, but it can also paralyze, making a person forget the words to an aria or lose a trusty golf swing. When someone falls into the trap of spending too much time thinking about fine-art posters or about the details of an MRI image, the rational brain is being used in the wrong way. The prefrontal cortex can't handle so much complexity by itself.

So far, this book has been about the brain's dueling systems. We've seen how both reason and feeling have important strengths and weaknesses, and how, as a result, different situations require different cognitive strategies. How we decide should depend on what we are deciding.

But before we learn how to take full advantage of our varied mental tools, we are going to explore a separate realm of decision-making. As it happens, some of our most important decisions are about how we treat other people. The human being is a social animal, endowed with a brain that shapes social behavior. By understanding how the brain makes these decisions, we can gain insight into one of most unique aspects of human nature: morality.

When John Wayne Gacy was a child, he liked to torture animals. He caught mice in a wire trap and then cut them open with scissors while they were still alive. The blood and guts didn't bother him. Neither did the squeals. Sadism was entertaining.

This streak of cruelty was one of the few noteworthy facts of Gacy's childhood. In just about every other respect, his early years were utterly normal. He grew up in the middle-class suburbs of Chicago, where he was a Boy Scout and delivered the local newspaper. He got good grades in school but didn't want to go to college. When his high school classmates were later asked what they remembered about Gacy, most couldn't remember anything. He blended in with the crowd.

Gacy grew up to become a successful construction contractor and a pillar of the community. He liked to throw big summer barbecues, grill hot dogs and hamburgers and invite the neighbors over. He dressed up as a clown for kids in the hospital and was active in local politics. The local chamber of commerce voted him Man of the Year. He was a typical suburban husband.

The normalcy, however, was a carefully crafted lie. One day, Gacy's wife noticed a pungent odor coming from the crawlspace underneath their house. It was probably just a dead rodent, Gacy said, or maybe a sewage leak. He bought a fifty-pound bag of lime and tried to erase the smell. But the smell wouldn't go away. Gacy filled in the space with concrete. The smell still wouldn't go away. There was something bad underneath those floorboards.

The smell was rotting bodies. On March 12, 1980, John Wayne Gacy was convicted of murdering thirty-three boys. He paid the boys for sex, and if something went awry with the transaction, he would kill them in his living room. Sometimes he killed one after he raised his price. Or if he thought the boy might tell somebody. Or if he didn't have enough cash in his wallet. Sometimes he killed a boy because it seemed like the easiest thing to do. He'd put a sock in his mouth, strangle him with a rope, and get rid of the corpse in the middle of the night. When the cops finally searched Gacy's home, they found skeletons everywhere: underneath his garage, in the basement, in the backyard. The graves were shallow, just a few inches deep.

John Wayne Gacy was a psychopath. Psychiatrists estimate that about 25 percent of the prison population have psychopathic tendencies, but the vast majority of these people will never kill anybody. While psychopaths are prone to violence—especially when the violence is used to achieve a goal, like satisfying a sexual desire—their neurological condition is best defined in terms of a specific brain malfunction: psychopaths make poor—sometimes disastrous—moral choices.

At first glance, it seems strange to think of psychopaths as decision-makers. We tend to label people like John Wayne Gacy as monsters, horrifying examples of humanity at its most inhuman. But every time Gacy murdered a boy, killing without the slightest sense of unease, he was making a decision. He was willingly violating one of the most ancient of moral laws:
thou shalt not kill.
And yet Gacy felt no remorse; his conscience was clean, and he slept like a baby.

Psychopaths shed light on a crucial subset of decision-making that's referred to as morality. Morality can be a squishy, vague concept, and yet, at its simplest level, it's nothing but a series of choices about how we treat other people. When you act in a moral manner—when you recoil from violence, treat others fairly, and help strangers in need—you are making decisions that take people besides yourself into account. You are thinking about the feelings of others, sympathizing with their states of mind. This is what psychopaths can't do.

What causes this profound deficit? On most psychological tests, psychopaths appear perfectly normal. The working memory isn't impaired, they use language normally, and they don't have reduced attention spans. In fact, several studies have found that psychopaths have above-average IQs and reasoning abilities. Their logic is impeccable. But this intact intelligence conceals a devastating disorder: psychopaths are dangerous because they have damaged emotional brains.

Just look at Gacy. According to a court-appointed psychiatrist, Gacy seemed incapable of experiencing regret, sadness, or joy. He never lost his temper or got particularly angry. Instead, his inner life consisted entirely of sexual impulses and ruthless rationality. He felt nothing, but planned everything. (Gacy's meticulous criminal preparations are what allowed him to evade the police for so long.) Alec Wilkinson, a journalist who spent hours interviewing Gacy on death row, described his eerily detached demeanor in
The New Yorker:

[Gacy] appears to have no inner being. I often had the feeling that he was like an actor who had created a role and polished it so carefully that he had become the role and the role had become him. In support of his innocence, he often says things that are deranged in their logic, but he says them so calmly that he appears to be rational and reasonable ... Compared to other murderers at the prison, Gacy seemed tranquil.

This sort of emotional emptiness is typical of psychopaths. When normal people are shown staged videos of strangers being subjected to pain—for example, receiving powerful electric shocks—they automatically generate visceral emotional reactions. Their hands start to sweat and their blood pressure surges. But psychopaths feel nothing. It's as if they were watching a blank screen. Most people react differently to emotionally charged verbs such as
kill
or
rape
than they do to neutral words such as
sit
or
walk,
but that's not the case with psychopaths. For them, the words all seem equivalent. When normal people tell lies, they exhibit the classic symptoms of nervousness; lie detectors work by measuring these signals. But psychopaths are able to consistently fool the machines. Dishonesty doesn't make them anxious because nothing makes them anxious. They can lie with impunity. When criminologists looked at the most violent wife batterers, they discovered that as those men became more and more aggressive, their blood pressure and pulse rates actually
dropped.
The acts of violence had a calming effect.

"Psychopaths have a fundamental emotional disorder," says James Blair, a cognitive psychologist at the National Institute of Mental Health and coauthor of
The Psychopath: Emotion and the Brain.
"You know when you see a scared face in a movie and that makes you automatically feel scared, too? Well, psychopaths don't feel that. It's like they don't understand what's going on. This lack of emotion is what causes their dangerous behavior. They are missing the primal emotional cues that the rest of us use as guides when making moral decisions."

When you peer inside the psychopathic brain, you can see this absence of emotion. After being exposed to fearful facial expressions, the emotional parts of the normal human brain show increased levels of activation. So do the cortical areas responsible for recognizing faces. As a result, a frightened face becomes a frightening sight; we naturally internalize the feelings of others. The brain of a psychopath, however, responds to these fearful faces with an utter lack of interest. The emotional areas are unperturbed, and the facial-recognition system is even
less
interested in fearful faces than it is in perfectly blank stares. The psychopath's brain is bored by expressions of terror.

While the anatomy of evil remains incomplete, neuroscientists are beginning to identify the specific deficits that define the psychopathic brain. The main problem seems to be a broken amygdala, a brain area responsible for propagating aversive emotions such as fear and anxiety. As a result, psychopaths never feel bad when they make other people feel bad. Aggression doesn't make them nervous. Terror isn't terrifying. (Brain-imaging studies have demonstrated that the human amygdala is activated when a person merely
thinks
about committing a "moral transgression.") This emotional void means that psychopaths never learn from their adverse experiences; they are four times more likely than other prisoners to commit crimes after being released. For a psychopath on parole, there is nothing inherently wrong with violence. Hurting someone else is just another way of getting what he wants, a perfectly reasonable way to satisfy desires. The absence of emotion makes the most basic moral concepts incomprehensible. G. K. Chesterton was right: "The madman is not the man who has lost his reason. The madman is the man who has lost everything except his reason."

AT FIRST GLANCE
, the connection between morality and the emotions might be a little unnerving. Moral decisions are supposed to rest on a firm logical and legal foundation. Doing the right thing means carefully weighing competing claims, like a
dis
passionate judge. These aspirations have a long history. The luminaries of the Enlightenment, such as Leibniz and Descartes, tried to construct a moral system entirely free of feelings. Immanuel Kant argued that doing the right thing was merely a consequence of acting rationally. Immorality, he said, was a result of illogic. "The oftener and more steadily we reflect" on our moral decisions, Kant wrote, the more moral those decisions become. The modern legal system still subscribes to this antiquated set of assumptions and pardons anybody who demonstrates a "defect in rationality"—these people are declared legally insane—since the rational brain is supposedly responsible for distinguishing between right and wrong. If you can't reason, then you shouldn't be punished.

But all of these old conceptions of morality are based on a fundamental mistake. Neuroscience can now see the substrate of moral decisions, and there's nothing rational about it. "Moral judgment is like aesthetic judgment," writes Jonathan Haidt, a psychologist at the University of Virginia. "When you see a painting, you usually know instantly and automatically whether you like it. If someone asks you to explain your judgment, you confabulate ... Moral arguments are much the same: Two people feel strongly about an issue, their feelings come first, and their reasons are invented on the fly, to throw at each other."