How We Decide (5 page)

WHY ARE OUR
emotions so essential? How did they get so good at finding the open man and directing soap operas? The answer is rooted in evolution. It takes a long time to design a brain. The first clumps of networked neurons appeared more than five hundred million years ago. This was the first nervous system, although at that point it was really just a set of automatic reflexes. Over time, however, primitive brains grew increasingly complex. They expanded from a few thousand neurons in earthworms to a hundred billion connected cells in Old World primates. When
Homo sapiens
first appeared, about two hundred thousand years ago, the planet was already full of creatures with highly specialized brains. There were fish that could migrate across the ocean using magnetic fields, and birds that navigated by starlight, and insects that could smell food from a mile away. These cognitive feats were all byproducts of instincts that had been engineered by natural selection to perform specific tasks. What these animals couldn't do, however, was reflect on their own decisions. They couldn't plan out their days or use language to express their inner states. They weren't able to analyze complex phenomena or invent new tools. What couldn't be done automatically couldn't be done at all. The charioteer had yet to appear.

The evolution of the human brain changed everything. For the first time, there was an animal that could think about how it thought. We humans could contemplate our emotions and use words to dissect the world, parsing reality into neat chains of causation. We could accumulate knowledge and logically analyze problems. We could tell elaborate lies and make plans for the future. Sometimes, we could even follow our plans.

These new talents were incredibly useful. But they were also incredibly new. As a result, the parts of the human brain that make them possible—the ones that the driver of the chariot controls—suffer from the same problem that afflicts any new technology: they have lots of design flaws and software bugs. (The human brain is like a computer operating system that was rushed to market.) This is why a cheap calculator can do arithmetic better than a professional mathematician, why a mainframe computer can beat a grand master at chess, and why we so often confuse causation and correlation. When it comes to the new parts of the brain, evolution just hasn't had time to work out the kinks.

The emotional brain, however, has been exquisitely refined by evolution over the last several hundred million years. Its software code has been subjected to endless tests, so it can make fast decisions based on very little information. Look, for instance, at the mental process involved in hitting a baseball. The numbers make the task look impossible. A typical major-league pitch takes about 0.35 seconds to travel from the hand of the pitcher to home plate. (This is the average interval between human heartbeats.) Unfortunately for the batter, it takes about 0.25 seconds for his muscles to initiate a swing, leaving his brain a paltry one-tenth of a second to make up its mind on whether or not to do so. But even this estimate is too generous. It takes a few milliseconds for the visual information to travel from the retina to the visual cortex, so the batter really has fewer than five milliseconds to perceive the pitch and decide if he should swing. But people can't think this quickly; even under perfect conditions, it takes the brain about twenty milliseconds to respond to a sensory stimulus.

So how does a major-league baseball player manage to hit a fastball? The answer is that the brain begins collecting information about the pitch long before the ball leaves the pitcher's hand. As soon as the pitcher begins his wind-up, the batter automatically starts to pick up on "anticipatory clues" that help him winnow down the list of possibilities. A torqued wrist suggests a curveball, while an elbow fixed at a right angle means that a fastball is coming, straight over the plate. Two fingers on the seam might indicate a slider, and a ball gripped with the knuckles is a sure sign that a wavering knuckleball is on its way. The batters, of course, aren't consciously studying these signs; they can't tell you why they decided to swing at certain pitches. And yet, they are able to act based on this information. For instance, a study of expert cricket batters demonstrated that the players could accurately predict the speed and location of the ball based solely on a one-second video of the pitcher's wind-up. The well-trained brain knew exactly what details to look for. And then, once it perceived these details, it seamlessly converted them into an accurate set of feelings. For a hitter in the major leagues, a hanging curveball over the center of the plate just
feels
like a better pitch than a slider, low and away.

We take these automatic talents for granted precisely because they work so well. There's no robot that can hit a baseball or throw a football or ride a bicycle. No computer program can figure out which actor should play a villain or instantly recognize a familiar face. This is why when evolution was building the brain, it didn't bother to replace all of those emotional processes with new operations under explicit, conscious control. If something isn't broken, then natural selection isn't going to fix it. The mind is made out of used parts, engineered by a blind watchmaker. The result is that the uniquely human areas of the mind depend on the primitive mind underneath. The process of thinking requires feeling, for feelings are what let us understand all the information that we can't directly comprehend. Reason without emotion is impotent.

One of the first scientists to defend this view of decision-making was William James, the great American psychologist. In his seminal 1890 textbook
The Principles of Psychology,
James launched into a critique of the standard "rationalist" account of the human mind. "The facts of the case are really tolerably plain," James wrote. "Man has a far
greater
variety of impulses than any other lower animal." In other words, the Platonic view of decision-making, which idealized man as a purely rational animal defined "by the almost total absence of instincts," was utterly mistaken. James's real insight, however, was that these impulses weren't necessarily bad influences. In fact, he believed that "the preponderance of habits, instincts and emotions" in the human brain was an essential part of what made the brain so effective. According to James, the mind contained two distinct thinking systems, one that was rational and deliberate and another that was quick, effortless, and emotional. The key to making decisions, James said, was knowing when to rely on which system.

Just look at Tom Brady. It's his feelings that allow him to make quick passing decisions in the pocket. For Brady, the process probably works something like this: After the ball is snapped, he drops back and tries to make sense of the field. He begins going through his checklist of receivers. The primary target, a tight end running a short crossing pattern, is tightly covered. As a result, when Brady glances at the tight end, he automatically feels a slight twinge of fear, the sure sign of a risky pass. The presence of the linebacker has been translated into a negative emotion. Brady then proceeds to his secondary target, a wide receiver running a deep out. Unfortunately, this target is double-teamed by a cornerback and a safety. Once again, Brady experiences a negative feeling, an instant distillation of what's happening on the football field. A few seconds have now elapsed, and Brady can feel the pressure of the defensive line. His left tackle is being pushed backward; Brady knows that he's got to get rid of the ball soon or the game is going to end with a sack. He proceeds to his third target. Troy Brown is streaking across the center of the field, threading the seam between the linebackers and the cornerbacks. When Brady looks at this target, his usual fear is replaced by a subtle burst of positive emotion, the allure of a receiver without a nearby defender. He has found the open man. He lets the ball fly.

In the early morning hours of February 24, 1991, the First and Second Marine divisions rolled north across the desert of Saudi Arabia. As they approached the unmarked border with Kuwait—the landscape was just an expanse of barren sand—the troops accelerated their pace. These Marines were the first Coalition forces to enter the country since it had been invaded by Iraq, more than eight months earlier. The outcome of Operation Desert Storm depended on their success. The Marines needed to liberate Kuwait, and they needed to do it in fewer than one hundred hours. If the Marines failed to overtake the Iraqi army quickly, they faced the prospect of urban warfare. The Iraqis were threatening to retreat into the streets of Kuwait City, and if that happened, the ground war could drag on for months.

The Marines expected heavy resistance. The Iraqis had fortified many of their military positions inside Kuwait, concentrating their forces near the Al Wafrah oil field along the Saudi Arabian border. They had draped a line of explosive mines across the desert. To make matters even more difficult, these Iraqi units had largely been spared the brutal air war. Because the Coalition forces were determined to minimize collateral damage and civilian casualties, bombing runs inside the occupied country were sharply restricted. Unlike the Republican Guard troops stationed in southern Iraq, a military force that had been decimated by thirty-seven days of intense bombing, these Marines were about to encounter an enemy at full strength. Central Command (CENTCOM) estimated that during the invasion of Kuwait, each Marine division would suffer approximately a thousand casualties, or between 5 and 10 percent of its total troop strength.

To support this high-stakes mission, a fleet of Coalition battleships and destroyers was positioned fewer than twenty miles off the Kuwaiti coast. This was a risky strategic move; although the big naval guns provided crucial air cover for the ground attack of Kuwait, they were also well within range of Iraqi missiles. On the morning of the Marine invasion, the American and British ships in the Persian Gulf were put on the highest possible alert. They were told to expect hostile fire.

The first twenty-four hours of the ground war exceeded even CENTCOM's high expectations. After successfully breaching the perimeter of mines and barbed wire put down by the Iraqis, the Marine division managed to penetrate deep into central Kuwait. Unlike the Soviet T-72 tanks used by the Iraqi army, the American M
I
Abrams tanks were equipped with GPS units and thermal sights, allowing the Marines to engage the enemy in the pitch-black night. After a brigade of Marines reached the outskirts of Kuwait City, they made an abrupt turn to the east and began the task of securing the coastline. Just before dawn on February 25, ten Marine helicopters, along with an amphibious landing ship, conducted a feint attack on a military base near the Kuwaiti port of Ash Shuaybah. The attack was supported by a barrage of artillery rounds from the offshore battleships. The Coalition forces weren't interested in capturing the port; they just wanted to "neutralize" it, to make sure it didn't pose a danger to the offshore convoy.

That same morning, while Ash Shuaybah was being attacked, Lieutenant Commander Michael Riley was monitoring the radar screens onboard the HMS
Gloucester,
a British destroyer stationed about fifteen miles from the port. The ship was responsible for protecting the Allied fleet, which meant that Riley had to monitor all of the airspace surrounding the naval convoy. Since the start of the air war, the radar crews had maintained an exhausting schedule. They were on duty for six hours, then they had six hours to sleep and eat, and after that brief respite, they headed back to the claustrophobic radar room. By the time the ground invasion began, the men were showing signs of fatigue. They had bloodshot eyes and needed constant infusions of caffeine.

Riley had been on duty since midnight. At 5:01 in the morning, just as the Allied ships began shelling Ash Shuaybah, he noticed a radar blip off the Kuwaiti coast. A quick calculation of its trajectory had it heading straight for the convoy. Although Riley had been staring at similar-looking blips all night long, there was something about this radar trace that immediately made him suspicious. He couldn't explain why, but the blinking green dot on the screen filled him with fear; his pulse started to race and his hands became clammy. He continued to observe the incoming blip for another forty seconds as it slowly honed in on the USS
Missouri,
an American battleship. With each sweep of the radar, the blip grew closer. It was approaching the American ship at more than 550 miles per hour. If Riley was going to shoot down the target—if he was going to act on his fear—then he needed to respond right away. If that blip was a missile and Riley didn't move immediately, it would be too late. Hundreds of sailors would die. The USS
Missouri
would be sunk. And Riley would have stood by and watched it happen.

But Riley had a problem. The radar blip was located in airspace that was frequently traveled by American A-6 fighter jets, which the U.S. Navy was using to deliver laser-guided bombs to support the Marine ground invasion. After completing their sorties, the planes flew down the Kuwait coast, turned east toward the convoy, and landed on their aircraft carriers. Over the last few weeks, Riley had watched dozens of A-6s fly a route nearly identical to the one being followed by this unidentified radar blip. The blip was also traveling at the same speed as the fighter jets and had a similar surface area. It looked exactly like an A-6 on the radar screen.

To make matters even more complicated, the A-6 pilots had gotten into the bad habit of turning off their electronic identification on their return flights. This identification system allowed Coalition forces to recognize their own, but it also made the planes more vulnerable to Iraqi antiaircraft missiles. Not surprisingly, the pilots opted for the cloak of silence over Iraqi-controlled airspace. As a result, the radar crew onboard the HMS
Gloucester
had no way of contacting this radar blip.

There was one last way for radar crews to distinguish between an incoming missile and a friendly aircraft: they could determine the altitude of the blip. The A-6 generally flew at around three thousand feet, while a Silkworm missile flew at one thousand feet. However, the type of radar that Riley was using didn't provide him with any altitude information. If he wanted to know the height of a specific object, he had to use a specialized radar system known as the 909, which conducted sweeps in horizontal bands. Unfortunately, the 909 radar operator had entered an incorrect tracking number shortly after the blip appeared, which meant that Riley had no way of knowing the altitude of the flying object. Although he'd now been staring at the radar blip for almost a minute, its identity remained a befuddling mystery.