The Invisible Gorilla: And Other Ways Our Intuition Deceives Us. Christopher Chabris
lead us to drive without noticing where we are going.53 A driver in Germany followed his navigation instructions despite several “closed for construction” signs and barricades, eventually barreling his Mercedes into a pile of sand. Twice in 2008, drivers in New York State blindly followed their GPS instructions and turned onto a set of train tracks in front of an oncoming train (neither was injured, fortunately). A driver in Britain caused a train crash after unwittingly driving onto the Newcastle-Carlisle rail line tracks.
A more common problem in Britain occurs when truck drivers follow their GPS commands onto streets that are too small for their trucks. In one case, a driver wedged his truck so firmly into a country lane that he couldn’t move backward, move forward, or even open his door. He had to sleep in his cab for three days before being towed out by a tractor. The problem, of course, is that the navigation system doesn’t know or take account of the size of the vehicle—and some of us don’t know that it doesn’t know. Our favorite example of GPS-induced blindness comes from the British town of Luckington. In April 2006, rising waters made a ford through the start of the Avon River temporarily impassable, so it was closed and markers were put on both sides. Every day during the two weeks following the closure, one or two cars drove right past the warning signs and into the river. These drivers apparently were so focused on their navigation displays that they didn’t see what was right in front of them.
Technology can help us to overcome the limits on our abilities, but only if we recognize that any technological aid will have limits too. If we misunderstand the limits of the technology, these aids can actually make us less likely to notice what is around us. In a sense, we tend to generalize our illusion of attention to the aids we use to overcome the limits on our attention. In the next chapter, we will consider this question: If we successfully pay attention to something and notice it, will it then be remembered? Most people think yes, but we will argue that this too is an illusion—the illusion of memory.
CHAPTER 2 the coach who choked
BEFORE RETIRING FROM COACHING COLLEGE basketball in 2008, Bobby Knight led his teams to victory in more than nine hundred college games, more than any other Division I coach. He was a four-time national coach of the year, led the 1984 Olympic gold medal basketball team that featured future NBA stars Michael Jordan and Patrick Ewing, and won three national collegiate titles as the coach of the Indiana University Hoosiers. He was famous for running a “clean” basketball operation: His organizations were never accused of the sorts of recruiting violations that plague many top-tier basketball programs, and the majority of his players completed their college degrees. He was a coaching innovator whom many of his former players credit for their personal and professional successes. Despite this unparalleled record of achievement, Bobby Knight was fired from Indiana University in September 2000 after an undergraduate yelled “Hey, Knight, what’s up?” and Knight responded by grabbing the student’s arm and lecturing him on being respectful.
That Knight’s dismissal was triggered by a lecture on respect is ironic. Throughout his coaching career, Knight had a national reputation for a volatile temper, crass behavior, and a disdainful attitude toward the press and others. He regularly berated referees and journalists, and on occasion, he even threw chairs onto the court. He was the subject of a Saturday Night Live parody in which Jim Belushi played a high school chess coach who knocked over an opponent’s pieces and yelled at his own player, “Move it! Move it! Move the bishop!” Compared with other events in his career, the “what’s up” incident was actually small beer. It was considered a firing offense only because of a report published earlier that year that had led the university to adopt a zero-tolerance policy for his future indiscretions.
In March 2000, CNN and Sports Illustrated ran a story about why several top recruits had left the Indiana program. It focused on an incident described by Neil Reed, one of Knight’s former players. Reed was a star recruit, a high school All-American who scored an average of about ten points per game during his three years at Indiana. During a practice in 1997, Knight confronted Reed for failing to call out a teammate’s name when making a pass, but Reed stood his ground against Knight, claiming he had in fact yelled the name. According to Reed, Knight then physically attacked him:
At that point coach thrust right at me, just came right at me, wasn’t far away enough to where I couldn’t see it coming, was close enough to come at me and reach and put his hand around my throat. He came at me with two hands but grabbed me with one hand. People came in and separated us like we were in a school yard to fight…He had me by the throat for I would probably say that little situation lasted about 5 seconds. I grabbed his wrist and started walking back and by this time people, coaches Dan Dakich, Felling grabbed coach Knight and pulled him away.
The national reporting of this incident caused a sensation and led Indiana officials to shorten their coach’s leash. Reed’s account vividly confirmed Knight’s stormy reputation and put it in an even darker light. But shortly after the Sports Illustrated report, other people present at the time told a different story. Knight’s former assistant Dan Dakich said, “His allegation that I had to separate him from coach Knight is totally false.” Another player who had been on the team at the time said, “The statement that he was choked by coach Knight is totally ridiculous.” Christopher Simpson, a vice president of the university who attended many practices, was quoted as saying about Reed’s statements, “…I question anything Neil Reed says.” The team’s trainer at the time, Tim Garl, stated baldly, “The choking thing never happened…give me a lie detector.” Bobby Knight himself said, “I might have grabbed him by the back of the neck. I might have grabbed the guy and moved him over. I mean, if you choke a guy, I would think he would need hospitalization.” Everyone involved believed that their memories had accurately recorded what had happened, but their recollections were contradictory.1
How We Think About Memory
This chapter is about this illusion of memory: the disconnect between how we think memory works and how it actually works. But how, exactly, do we think it works? Before answering this question, we’d like you to try a brief memory test. Read through the following list of words: bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy. We’ll get back to them in a few paragraphs.
Most of us cannot remember a fifteen-digit number, and we know that we cannot, so we do not even try. We all sometimes forget where we put our car keys (or our car), we fail to recall a friend’s name, or we neglect to pick up the dry cleaning on the way home from work. And we know that we often make these mistakes—our intuitive beliefs about such everyday memory failures are reasonably accurate. Our intuitions about the persistence and detail of memory are a different story.
In the national survey of fifteen hundred people we commissioned in 2009, we included several questions designed to probe how people think memory works. Nearly half (47%) of the respondents believed that “once you have experienced an event and formed a memory of it, that memory doesn’t change.” An even greater percentage (63%) believed that “human memory works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.” People who agreed with both statements apparently think that memories of all our experiences are stored permanently in our brains in an immutable form, even if we can’t access them. It is impossible to disprove this belief—the memories could in principle be stored somewhere—but most experts on human memory find it implausible that the brain would devote energy and space to storing every detail of our lives (especially if that information could never be accessed).2
Just as the illusion of attention leads us to think that important and distinctive events capture our attention when they don’t, the illusion of memory reflects a basic contrast between what we think we remember and what we actually remember. Why do people easily grasp the limitations of short-term memory, but misunderstand