The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us

Introduction: Everyday Illusions

1.
“I Think I Would Have Seen That”

2.
The Coach Who Choked

3.
What Smart Chess Players and Stupid Criminals Have in Common

4.
Should You Be More Like a Weather Forecaster or a Hedge Fund Manager?

5.
Jumping to Conclusions

6.
Get Smart Quick!

Conclusion: The Myth of Intuition

Acknowledgments

Notes

A
BOUT TWELVE YEARS AGO,
we conducted a simple experiment with the students in a psychology course we were teaching at Harvard University. To our surprise, it has become one of the best-known experiments in psychology. It appears in textbooks and is taught in introductory psychology courses throughout the world. It has been featured in magazines such as
Newsweek
and
The New Yorker
and on television programs, including
Dateline NBC
. It has even been exhibited in the Exploratorium in San Francisco and in other museums. The experiment is popular because it reveals, in a humorous way, something unexpected and deep about how we see our world—and about what we don’t see.

You’ll read about our experiment in the first chapter of this book. As we’ve thought about it over the years, we’ve realized that it illustrates a broader principle about how the mind works. We all believe that we are
capable of seeing what’s in front of us, of accurately remembering important events from our past, of understanding the limits of our knowledge, of properly determining cause and effect. But these intuitive beliefs are often mistaken ones that mask critically important limitations on our cognitive abilities.

We must be reminded not to judge a book by its cover because we take outward appearances to be accurate advertisements of inner, unseen qualities. We need to be told that a penny saved is a penny earned because we think about cash coming in differently from money we already have. Aphorisms like these exist largely to help us avoid the mistakes that intuition can cause. Likewise, Benjamin Franklin’s observation about extremely hard things suggests that we should question the intuitive belief that we understand ourselves well. As we go through life, we act as though we know how our minds work and why we behave the way we do. It is surprising how often we really have no clue.

The Invisible Gorilla
is a book about six everyday illusions that profoundly influence our lives: the illusions of attention, memory, confidence, knowledge, cause, and potential. These are distorted beliefs we hold about our minds that are not just wrong, but wrong in dangerous ways. We will explore when and why these illusions affect us, the consequences they have for human affairs, and how we can overcome or minimize their impact.

We use the word “illusions” as a deliberate analogy to visual illusions like M. C. Escher’s famous never-ending staircase: Even after you realize that something about the picture as a whole is not right, you still can’t stop yourself from seeing each individual segment as a proper staircase. Everyday illusions are similarly persistent: Even after we know how our beliefs and intuitions are flawed, they remain stubbornly resistant to change. We call them
everyday
illusions because they affect our behavior literally every day. Every time we talk on a cell phone while driving, believing we’re still paying enough attention to the road, we’ve been affected by one of these illusions. Every time we assume that someone who misremembers their past must be lying, we’ve succumbed to an illusion. Every time we pick a leader for a team because that person expresses the
most confidence, we’ve been influenced by an illusion. Every time we start a new project convinced that we know how long it will take to complete, we are under an illusion. Indeed, virtually no realm of human behavior is untouched by everyday illusions.

As professors who design and run psychology experiments for a living, we’ve found that the more we study the nature of the mind, the more we see the impact of these illusions in our own lives. You can develop the same sort of x-ray vision into the workings of your own mind. When you finish this book, you will be able to glimpse the man behind the curtain and some of the tiny gears and pulleys that govern your thoughts and beliefs. Once you know about everyday illusions, you will view the world differently and think about it more clearly. You will see how illusions affect your own thoughts and actions, as well as the behavior of everyone around you. And you will recognize when journalists, managers, advertisers, and politicians—intentionally or accidentally—take advantage of illusions in an attempt to obfuscate or persuade. Understanding everyday illusions will lead you to recalibrate the way you approach your life to account for the limitations—and the true strengths—of your mind. You might even come up with ways to exploit these insights for fun and profit. Ultimately, seeing through the veils that distort how we perceive ourselves and the world will connect you—for perhaps the first time—with reality.

A
ROUND TWO O’CLOCK
on the cold, overcast morning of January 25, 1995, a group of four black men left the scene of a shooting at a hamburger restaurant in the Grove Hall section of Boston
¹
As they drove away in a gold Lexus, the police radio erroneously announced that the victim was a cop, leading officers from several districts to join in a ten-mile high-speed chase. In the fifteen to twenty minutes of mayhem that ensued, one police car veered off the road and crashed into a parked van. Eventually the Lexus skidded to a stop in a cul-de-sac on Woodruff Way in the Mattapan neighborhood. The suspects fled the car and ran in different directions.

One suspect, Robert “Smut” Brown III, age twenty-four, wearing a dark leather jacket, exited the back passenger side of the car and sprinted toward a chain-link fence on the side of the cul-de-sac. The first car in pursuit, an unmarked police vehicle, stopped to the left of the Lexus. Michael Cox, a decorated officer from the police antigang unit who’d grown up in the nearby Roxbury area, got out of the passenger seat and took off after Brown. Cox, who also is black, was in plainclothes that night; he wore jeans, a black hoodie, and a parka.
²

Cox got to the fence just after Smut Brown. As Brown scrambled over the top, his jacket got stuck on the metal. Cox reached for Brown and tried to pull him back, but Brown managed to fall to the other side. Cox prepared to scale the fence in pursuit, but just as he was starting to climb, his head was struck from behind by a blunt object, perhaps a baton or a flashlight. He fell to the ground. Another police officer had mistaken him for a suspect, and several officers then beat up Cox, kicking him in the head, back, face, and mouth. After a few moments, someone yelled, “Stop, stop, he’s a cop, he’s a cop.” At that point, the officers fled, leaving Cox lying unconscious on the ground with facial wounds, a concussion, and kidney damage.
³