The Invisible Gorilla: And Other Ways Our Intuition Deceives Us. Christopher Chabris
while Knight remembered nothing at all? Before the tape surfaced, Knight told HBO’s Frank Deford that he didn’t remember choking Reed, and added, “There isn’t anything that I have done with one kid that I haven’t done with a lot of other kids.”8 For Knight, this was an unremarkable event—it was business as usual. His memory for the event was distorted to become consistent with his broader beliefs and expectations for what happens at practices: Coaches grab kids and move them around, showing them where to stand and what to do. Physical contact, for Knight, is a regular part of coaching. He misremembered the event as being less consequential than it was, distorting it to be more consistent with his own beliefs about typical coaching situations. For Reed, this event likely was far more consequential. As he noted, he was a “twenty-year-old kid” at the time and he probably hadn’t been grabbed by the neck often in practice. To him, it was a jarring and unusual event, one that he stored in his memory as “coach choked me.” He remembered the event based on the ways that it was salient to him, and as a result, it was distorted in the opposite direction from Knight’s version, becoming traumatic rather than trivial. For Knight, the incident was just like another arbitrary word in a list. For Reed, the incident had a powerful meaning, and the details were filled in accordingly.
People involved in the case of Neil Reed and Bobby Knight had sharply different recollections of what happened, but by the time they told their stories to the media in 2000, several years had already passed since the incident. It’s not unreasonable to think that memories can fade and morph over the years, and that they can be influenced by the motives and goals of the rememberer. But what if two people witness the exact same incident, and the delay before they have to describe it is no more than the length of time spent on hold waiting for a 911 operator?9
Leslie Meltzer and Tyce Palmaffy, a young couple who had met as undergraduates at the University of Virginia, were on their way home from dinner on a summer night in 2002 in Washington, D.C. They drove their Camry north on Fourteenth Street and stopped at a traffic light at the intersection of Rhode Island Avenue.10 Today, it costs upward of $300,000 to buy a small apartment near the Whole Foods supermarket in this area, but then, the neighborhood was still recovering from the effects of race riots and arson that took place in the 1960s. Tyce, a writer on education policy, was driving. His wife, Leslie, who had recently earned a law degree at Yale, was in the passenger seat. To her right, Leslie saw a man riding a bicycle down the sidewalk in their direction. Suddenly, seemingly out of nowhere, another man approached the cyclist, pulled him off the bicycle, and began stabbing him repeatedly. Leslie heard the victim scream. She grabbed her cell phone and dialed 911, only to be greeted by a voice saying, “You have reached the emergency 911 service, all lines are busy, please hold.”
By the time the 911 operator got on the line, less than a minute had passed, but the assault was over and the light had turned green. Leslie described what she saw as they continued driving with the traffic down Fourteenth Street. The victim was a man in his twenties or thirties riding a bicycle. What about the assailant? He was dressed in jeans, she said. Overhearing her, Tyce interrupted to say that he was wearing sweatpants. They also disagreed about the kind of shirt he was wearing, how tall he was, and even whether he was black or Hispanic. They soon realized that they could agree only on the attacker’s age (twenties), on his weapon (a knife), and on the fact that they were not painting the clearest picture for the operator.
It is rare to witness exactly the same event, from the same vantage point as someone else, and then try to recall it in the presence of the other witness so soon afterward. Normally, when we observe an event, we store some memory of it. When we later recall the event, we do our best to retrieve our memory and report its contents. The memory seems vivid to us, and we typically lack any specific reason to doubt its accuracy. Had Tyce not been there to hear and correct—or at least contradict—Leslie’s report to the 911 operator, neither would have discovered the stark contradictions between their separate memories. Both were surprised by the extent of the differences. Tyce later recalled realizing right after the unnerving experience “how unbelievably untrustworthy witnesses must be,” an issue we’ll return to later in this book.
Didn’t They Just Shoot Up His Windshield?
In a famous scene in the movie Pretty Woman, Julia Roberts is having breakfast with Richard Gere in his hotel room. She picks up a croissant but then takes a bite out of a pancake. In Jagged Edge, Glenn Close’s outfit changes three times during a single courtroom scene. In The Godfather, Sonny’s car is riddled with bullets at a tollbooth, but seconds later its windshield is miraculously repaired. Did you know about these mistakes or others like them? These inadvertent changes, known as continuity errors, are common in movies, in part because of how movies are created. Rarely are movies shot in sequence and in real time from start to finish. They are completed piecemeal, with scenes filmed in an order determined by the actors’ schedules, the availability of physical locations for filming, the cost of hiring the crew at different times, the weather conditions, and many other factors. Each scene is filmed from many different angles, and the final movie is spliced together and put in order in the editing room.
Just one person on the set is responsible for making sure that everything in each scene matches from one shot to the next.11 That person, known as the script supervisor, is charged with remembering all of the details: what people were wearing, where they were standing, which foot was forward, whether a hand was on a waist or in a pocket, whether an actress was eating a croissant or a pancake, and whether the windshield should be intact or bullet-ridden. If the script supervisor makes a mistake during filming, it’s often impossible to go back and reshoot the scene. And the editor may decide to ignore the error because other aspects of the shot are more important. As a result, some mistakes almost inevitably make it into the final product. That’s why some of the slaves in Spartacus, set during the Roman Empire, can occasionally be seen wearing wristwatches.
Dozens of books and websites are devoted to cataloging such errors for the curious and obsessed.12 For The Godfather, one site lists forty-two separate continuity errors (plus dozens of other mistakes and anomalies). In part, such lists appeal because of the irony involved: Hollywood, despite spending tens of millions of dollars on a movie, makes clear mistakes that anyone can see. Finding such errors gives the amateur continuity sleuth a feeling of superiority—the filmmakers must have been sloppy not to notice what I can see clearly. And indeed, when you see an error in a movie, it suddenly seems obvious.
Several years ago, Dateline NBC ran a story on film flubs in movies like Shakespeare in Love and Saving Private Ryan, which had both won Academy Awards and been acclaimed for their editing. Correspondent Josh Mankiewicz revealed an error in Saving Private Ryan in which eight soldiers walked across a field in the distance, even though one had been killed a few minutes earlier in the film, so by then there should have been only seven soldiers. In a disbelieving voice, he said, “This is Steven Spielberg, one of the most talented and most careful moviemakers out there. You’ve got to figure he watched the film several times before it actually got to the theaters. And he didn’t see it?” Later, Mankiewicz asked, “What is it about filmmakers that they can shoot so carefully, many takes, and still miss something so obvious, something the audience can see clearly?” The questions are nearly perfect illustrations of how the illusion of memory operates. Mankiewicz (and his producers) assumed that people have an accurate memory of everything that has happened and that they will automatically notice any discrepancies.13
When they were in graduate school together at Cornell, Dan and his friend Daniel Levin (now a professor at Vanderbilt University) decided to explore experimentally how well people actually notice such errors in movies.14 With this project “the two Dans” began a long, productive, and ongoing collaboration. For their first study, they made a brief movie of a conversation between two friends, Sabina and Andrea, about