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Kenny Conley’s Invisible Gorilla

Dick Lehr brought Kenny Conley to Dan’s laboratory because he had heard about our gorilla experiment, and he wanted to see how Conley would do in it. Conley was physically imposing, but stoic and taciturn; Lehr did most of the talking that day. Dan led them to a small, windowless room in his laboratory and showed Conley the gorilla video, asking him to count the passes by the players wearing white. In advance, there was no way to know whether or not Conley would notice the unexpected gorilla—about half of the people who watch the video see the gorilla. Moreover, Conley’s success or failure in noticing the gorilla would not tell us whether or not he saw Michael Cox being beaten on Woodruff Way six years earlier. (These are both important points, and we will return to them shortly.) But Dan was still curious about how Conley would react when he heard about the science.

Conley counted the passes accurately and saw the gorilla. As is usual for people who do see the gorilla, he seemed genuinely surprised that anyone else could possibly miss it. Even when Dan explained that people often miss unexpected events when their attention is otherwise engaged, Conley still had trouble accepting that anyone else could miss what seemed so obvious to him.

The illusion of attention is so ingrained and pervasive that everyone involved in the case of Kenny Conley was operating under a false notion of how the mind works: the mistaken belief that we pay attention to—and therefore should notice and remember—much more of the world around us than we actually do. Conley himself testified that he should have seen the brutal beating of Michael Cox had he actually run right past it. In their appeal of his conviction, Conley’s lawyers tried to show that he hadn’t run past the beating, that the testimony about his presence near the beating was wrong, and that descriptions of the incident from other police officers were inaccurate. All of these arguments were founded on the assumption that Conley could only be telling the truth if he didn’t have the opportunity to see the beating. But what if, instead, in the cul-de-sac on Woodruff Way, Conley found himself in a real-life version of our gorilla experiment? He could have been right next to the beating of Cox, and even focused his eyes on it, without ever actually seeing it.

Conley was worried about Smut Brown scaling the fence and escaping, and he pursued his suspect with a single-minded focus that he described as “tunnel vision.” Conley’s prosecutor ridiculed this idea, saying that what prevented Conley from seeing the beating was not tunnel vision but video editing—“a deliberate cropping of Cox out of the picture.”¹⁴

But if Conley was sufficiently focused on Brown, in the way our subjects were focused on counting the basketball passes, it is entirely possible that he ran right past the assault and still failed to see it. If so, the only inaccurate part of Conley’s testimony was his stated belief that he should have seen Cox. What is most striking about this case is that Conley’s own testimony was the primary evidence that put him near the beating, and that evidence, combined with a misunderstanding of how the mind works, and the blue wall of silence erected by the other cops, led prosecutors to charge him with perjury and obstruction of justice. They, and the jury that convicted him, assumed that he too was protecting his comrades.

Kenny Conley’s conviction was eventually overturned on appeal and set aside in July 2005. But Conley prevailed not because the prosecutors or a judge were convinced that he actually was telling the truth. Instead, the appeals court in Boston ruled that he had been denied a fair trial because the prosecution didn’t tell his defense attorneys about an FBI memo that cast doubt on the credibility of one of the government’s witnesses.¹⁵ When the government decided not to retry him in September 2005, Conley’s legal troubles were finally over. On May 19, 2006, more than eleven years after the original incident on Woodruff Way that changed his life, Conley was reinstated as a Boston police officer—but only after being forced to redo, at age thirty-seven, the same police academy training a new recruit has to endure.¹⁶ He was granted $647,000 in back pay for the years he was off the force,¹⁷ and in 2007 he was promoted to detective.¹⁸

Throughout this book, we will present many examples and anecdotes, like the story of Kenny Conley, that show how everyday illusions can have tremendous influence on our lives. However, two important caveats are in order. First, as Robert Pirsig writes in Zen and the Art of Motorcycle Maintenance, “The real purpose of scientific method is to make sure Nature hasn’t misled you into thinking you know something that you actually don’t.”¹⁹ But science can only go so far, and although it can tell us in general how galaxies form, how DNA is transcribed into proteins, and how our minds perceive and remember our world, it is nearly impotent to explain a single event or individual case. The nature of everyday illusions almost never allows for proof that any particular incident was caused entirely by a specific mental mistake. There is no certainty that Conley missed the beating because of inattentional blindness, nor is there even certainty that he missed it at all (he could have seen it and then consistently lied). Without doing a study of attention under the same conditions Conley faced (at night, running after someone climbing a fence, the danger in chasing a murder suspect, the unfamiliar surroundings, and a gang of men attacking someone), we cannot estimate the probability that Conley missed what he said he missed.

We can, however, say that the intuitions of the people who condemned and convicted him were way off the mark. What is certain is that the police investigators, the prosecutors, and the jurors, and to some extent Kenny Conley himself, were all operating under the illusion of attention and failed to consider the possibility—which we argue is a strong possibility—that Conley could have been telling the truth about both where he was and what he didn’t see on that January night in Boston.

The second important point to keep in mind is this: We use stories and anecdotes to convey our arguments because narratives are compelling, memorable, and easily understood. But people tend to believe convincing, retrospective stories about why something happened even when there is no conclusive evidence of the event’s true causes. For that reason, we try to back up all of our examples with scientific research of the highest quality, using endnotes to document our sources and provide additional information along the way.

Our goals are to show you how everyday illusions influence our thoughts, decisions, and actions, and to convince you that they have large effects on our lives. We believe that once you have considered our arguments and evidence, you will agree, and that you will think about your own mind and your own behavior much differently. We hope that you will then act accordingly. So as you read on, read critically, keeping your mind open to the possibility that it doesn’t work the way you think it does.

The Nuclear Submarine and the Fishing Boat

Do you remember the first major international incident of George W. Bush’s presidency? It happened less than a month after he took office, on February 9, 2001.²⁰ At approximately 1:40 p.m., Commander Scott Waddle, captaining the nuclear submarine USS Greeneville near Hawaii, ordered a surprise maneuver known as an “emergency deep,” in which the submarine suddenly dives. He followed this with an “emergency main ballast tank blow,” in which high-pressure air forces water from the main ballasts, causing the submarine to surface as fast as it can. In this kind of maneuver, shown in movies like The Hunt for Red October, the bow of the submarine actually heaves out of the water. As the Greeneville zoomed toward the surface, the crew and passengers heard a loud noise, and the entire ship shook. “Jesus!” said Waddle. “What the hell was that?”

His ship had surfaced, at high speed, directly under a Japanese fishing vessel, the Ehime Maru. The Greeneville’s rudder, which had been specially reinforced for penetrating ice packs in the Arctic, sliced the fishing boat’s hull from one side to the other. Diesel fuel began to leak and the Ehime Maru took on water. Within minutes, it tipped up and sank by its stern as the people onboard scrambled forward toward the bow. Many of them reached the three lifeboats and were rescued, but three crew members and six passengers died. The Greeneville received only minor damage, and no one onboard was injured.

What went wrong? How could a modern, technologically advanced submarine, equipped with state-of-the-art sonar and manned by an experienced crew, not detect a nearly two-hundred-foot-long fishing boat so close by? In attempting to explain this accident, the National Transportation Safety Board’s fifty-nine-page report exhaustively documents all of the ways in which the officers failed to follow procedure, all of the distractions they faced in accommodating a delegation of civilian visitors, all of the errors they made along the way, and all of the miscommunication that contributed to poor tracking of the Ehime Maru’s actual position. It contains no evidence of alcohol, drugs, mental illness, fatigue, or personality conflicts influencing the crew’s actions. The report is most interesting, however, for the crucial issue it does not even attempt to resolve: why Commander Waddle and the officer of the deck failed to see the Ehime Maru when they looked through the periscope.

Before a submarine performs an emergency deep maneuver, it returns to periscope depth so the commander can make sure no other ships are in the vicinity. The Ehime Maru should have been visible through the periscope, and Commander Waddle looked right toward it, but he still missed it. Why? The NTSB report emphasized the brevity of the periscope scan, as did Dateline NBC correspondent Stone Phillips: “…had Waddle stayed on the periscope longer, or raised it higher, he might have seen the Ehime Maru. He says there is no doubt he was looking in the right direction.” None of these reports consider any other reasons why Waddle could have failed to see the nearby vessel—a failure that surprised Waddle himself. But the results of our gorilla experiment tell us that the USS Greeneville’s commanding officer, with all his experience and expertise, could indeed have looked right at another ship and just not have seen it. The key lies in what he thought he would see when he looked: As he said later, “I wasn’t looking for it, nor did I expect it.”²¹

Submarines rarely surface into other ships, so don’t lose sleep over the prospect on your next boat trip. But this kind of “looked but failed to see” accident is quite common on land. Perhaps you have had the experience of starting to turn out of a parking lot or a side road and then having to stop suddenly to avoid hitting a car you hadn’t seen before that moment. After accidents, drivers regularly claim, “I was looking right there and they came out of nowhere…I never saw them.”²² These situations are especially troubling because they run counter to our intuitions about the mental processes involved in attention and perception. We think we should see anything in front of us, but in fact we are aware of only a small portion of our visual world at any moment. The idea that we can look but not see is flatly incompatible with how we understand our own minds, and this mistaken understanding can lead to incautious or overconfident decisions.

In this chapter, when we talk about looking, as in “looking without seeing,” we don’t mean anything abstract or vague or metaphorical. We literally mean looking right at something. We truly are arguing that directing our eyes at something does not guarantee that we will consciously see it. A skeptic might question whether a subject in the gorilla experiment or an officer chasing a suspect or a submarine commander bringing his ship to the surface actually looked right at the unexpected object or event. To perform these tasks, though (to count the passes, pursue a suspect, or sweep the area for ships), they needed to look right where the unexpected object appeared. It turns out that there is a way, in a laboratory situation at least, to measure exactly where on a screen a person fixates their eyes (a technical way of saying “where they are looking”) at any moment. This technique, which uses a device called an “eye tracker,” can provide a continuous trace showing where and for how long a subject is looking during any period of time—such as the time of watching the gorilla video. Sports scientist Daniel Memmert of Heidelberg University ran our gorilla experiment using his eye tracker and found that the subjects who failed to notice the gorilla had spent, on average, a full second looking right at it—the same amount of time as those who did see it!²³

Ben Roethlisberger’s Worst Interception

In February 2006, at the age of twenty-three and in just his second season as a professional football player, Ben Roethlisberger became the youngest quarterback in NFL history to win a Super Bowl. During the off-season, on June 12 of that same year, he was riding his black 2005 Suzuki motorcycle heading outbound from downtown Pittsburgh on Second Avenue.²⁴ As he neared the intersection at Tenth Street, a Chrysler New Yorker driven by Martha Fleishman approached in the opposite direction on Second Avenue. Both vehicles had green lights when Fleishman then turned left onto Tenth Street, cutting off Roethlisberger’s motorcycle. According to witnesses, Roethlisberger was thrown from his motorcycle, hit the Chrysler’s windshield, tumbled over the roof and off the trunk, and finally landed on the street. His jaw and nose were broken, many of his teeth were knocked out, and he received a large laceration on the back of his head, as well as a number of other minor injuries. He required seven hours of emergency surgery, but considering that he wasn’t wearing a helmet, he was lucky to survive the crash at all. Fleishman had a nearly perfect driving record—the only mark against her was a speeding ticket nine years earlier. Roethlisberger was cited for not wearing a helmet and for driving without the right type of license; Fleishman was cited and fined for failing to yield. Roethlisberger eventually made a full recovery from the accident and was ready to resume his role as the starting quarterback by the season opener in September.

Accidents like this one are unfortunately common. More than half of all motorcycle accidents are collisions with another vehicle. Nearly 65 percent of those happen much like Roethlisberger’s—a car violates the motorcycle’s right-of-way, turning left in front of the motorcyclist (or turning right in countries where cars drive on the left side of the road).²⁵ In some cases, the car turns across oncoming traffic onto a side street. In others, the car turns across a lane of traffic onto the main street. In the typical accident of this sort, the driver of the car often says something like, “I signaled to turn left, and started out when it was clear. Then something hit my car and I later saw the motorcycle and the guy lying in the street. I never saw him!” The motorcyclist in such accidents says, “All of a sudden this car pulled out in front of me. The driver was looking right at me.” This experience leads some motorcyclists to assume that car drivers violate their right-of-way intentionally—that they see the motorcyclist and turn anyway.

Why do drivers turn in front of motorcyclists? We favor, at least for some cases, an explanation that appeals to the illusion of attention. People don’t see the motorcyclists because they aren’t looking for motorcyclists. If you are trying to make a difficult left turn across traffic, most of the vehicles blocking your path are cars, not motorcycles (or bicycles, or horses, or rickshaws…). To some extent, then, motorcycles are unexpected. Much like the subjects in our gorilla experiment, drivers often fail to notice unexpected events, even ones that are important. Critically, though, they assume they will notice—that as long as they are looking in the right direction, unexpected objects and events will grab their attention.

How can we remedy this situation? Motorcycle safety advocates propose a number of solutions, most of which we think are doomed to fail. Posting signs that implore people to “look for motorcycles” might lead drivers to adjust their expectations and become more likely to notice a motorcycle appearing shortly after the sign. Yet, after a few minutes of not seeing any motorcycles, their visual expectations will reset, leading them to again expect what they see most commonly—cars. Such advertising campaigns assume that the mechanisms of attention are permeable, subject to influence from our intentions and thoughts. Yet, the wiring of our visual expectations is almost entirely insulated from our conscious control. As we will discuss extensively in Chapter 4, our brains are built to detect patterns automatically, and the pattern we experience when driving features a preponderance of cars and a dearth of motorcycles. In other words, the ad campaign itself falls prey to the illusion of attention.

Suppose that one morning, we told you to watch for gorillas. Then, at some point a week later, you participated in our gorilla experiment. Do you think our warning would have any effect? Most likely not; in the time between the warning and the experiment, your expectations would have been reset by your daily experience of seeing no gorillas. The warning would only be useful if we gave it shortly before showing you the video.

Only when people regularly look for and expect motorcycles will they be more likely to notice. In fact, a detailed analysis of sixty-two accident reports involving cars and motorcycles found that none of the car drivers had any experience riding motorcycles themselves.²⁶ Perhaps the experience of riding a motorcycle can mitigate the effects of inattentional blindness for motorcycles. Or, put another way, the experience of being unexpected yourself might make you better able to notice similar unexpected events.

Another common recommendation to improve the safety of motorcycles is for riders to wear bright clothing rather than the typical attire of leather jacket, dark pants, and boots. The intuition seems right: A yellow jumpsuit should make the rider more visually distinctive and easier to notice. But as we’ve noted, looking is not the same as seeing. You can look right at the gorilla—or at a motorcycle—without seeing it. If the gorilla or motorcycle were physically imperceptible, that would be trivially true—nobody would be surprised if you failed to see a gorilla that was perfectly camouflaged in a scene. What makes the evidence for inattentional blindness important and counterintuitive is that the gorilla is so obvious once you know it is there. So looking is necessary for seeing—if you don’t look at it, you can’t possibly see it. But looking is not sufficient for seeing—looking at something doesn’t guarantee that you will notice it. Wearing conspicuous clothing and riding a brightly colored motorcycle will increase your visibility, making it easier for people who are looking for you to see you. Such bright clothing doesn’t guarantee that you will be noticed, though.

We did not always realize this ourselves. When we first designed the gorilla experiment, we assumed that making the “gorilla” more distinctive would lead to greater detection—of course people would notice a bright red gorilla. Given the rarity of red gorilla suits, we and our colleagues Steve Most (then a graduate student in Dan’s lab and now a professor at the University of Delaware) and Brian Scholl (then a postdoctoral fellow in the psychology department and now a professor at Yale) created a computerized version of the “gorilla” video in which the players were replaced by letters and the gorilla was replaced by a red cross (+) that unexpectedly traversed the display.²⁷ Subjects counted how many times the white letters touched the sides of the display window while ignoring the black letters.

Even jaded researchers like us were surprised by the result: 30 percent of viewers missed the bright red cross, even though it was the only cross, the only colored object, and the only object that moved in a straight path through the display. We thought the gorilla had gone unnoticed, at least in part, because it didn’t really stand out: It was dark-colored, like the players wearing black. Our belief that a distinctive object should “pop out” overrode our knowledge of the phenomenon of inattentional blindness. This “red gorilla” experiment shows that when something is unexpected, distinctiveness does not at all guarantee that we will notice it.

Reflective clothing helps increase visibility for motorcyclists, but it doesn’t override our expectations. Motorcyclists are analogous to the cross in this experiment. People fail to see them, but not just because they are smaller or less distinctive than the other vehicles on the road. They fail to see the motorcycles precisely because they stand out. Wearing highly visible clothing is better than wearing invisible clothing (and less of a technological challenge), but increasing the visual distinctiveness of the rider might be of limited use in helping drivers notice motorcyclists. Ironically, what likely would work to increase detection of motorcycles is to make them look more like cars. For example, giving motorcycles two headlights separated as much as possible, to resemble the visual pattern of a car’s headlights, could well increase their detectability.

There is one proven way to eliminate inattentional blindness, though: Make the unexpected object or event less unexpected. Accidents with bicyclists and pedestrians are much like motorcycle accidents in that car drivers often hit the bikers or walkers without ever seeing them. Peter Jacobsen, a public health consultant in California, examined the rates of accidents involving cars and either pedestrians or bicyclists across a range of cities in California and in a number of European countries.²⁸ For each city, he collected data on the number of injuries or fatalities per million kilometers people traveled by biking and by walking in the year 2000. The pattern was clear, and surprising: Walking and biking were the least dangerous in the cities where they were done the most, and the most dangerous where they were done the least.

Why are motorists less likely to hit pedestrians or bicyclists where there are more people bicycling or walking? Because they are more used to seeing pedestrians. Think of it this way: Would you be safer crossing the pedestrian-clogged streets of London, where drivers are used to seeing people swarm around cars, or the wide, almost suburban boulevards of Los Angeles, where drivers are less accustomed to people popping up right in front of their cars without warning? Jacobsen’s data show that if you were to move to a town with twice as many pedestrians, you would reduce your chance of being hit by a car while walking by one-third.

In one of the most striking demonstrations of the power of expectations,²⁹ Steve Most, who led the “red gorilla” study, and his colleague Robert Astur of the Olin Neuropsychiatry Research Center in Hartford, Connecticut, conducted an experiment using a driving simulator. Just before arriving at each intersection, subjects looked for a blue arrow that indicated which way they should turn, and they ignored yellow arrows. Just as subjects entered one of the intersections, a motorcycle unexpectedly drove right into their path and stopped. When the motorcycle was blue, the same color as the attended direction arrows, almost all of the drivers noticed it. When it was yellow, matching the ignored direction arrows, 36 percent of them hit the motorcycle, and two of them failed to apply their brakes at all! Your moment-to-moment expectations, more than the visual distinctiveness of the object, determine what you see—and what you miss.

Of course, not every automobile-versus-motorcycle collision is entirely the fault of the person driving the car. In the Ben Roethlisberger accident, the driver and the rider both had green lights, but Roethlisberger was going straight and had the right-of-way. A witness at the scene quoted Martha Fleishman, the driver of the car, as saying, “I was watching him approach but he was not looking at me.”³⁰ Roethlisberger might never have seen Fleishman’s car, even though it was right in front of him. Had he seen it, he might have been able to avoid the accident.