Subliminal

as being on the list unless you are sure of it and can picture it there. Please settle on your answer. Now please uncover the list in the previous paragraph and see how you did.

The vast majority of people recall with great confidence that “point” was not on the list. The majority also recall that “taste” was. The punch line of the exercise has to do with the other word: “sweet.” If you recalled seeing that word, it is an illustration of the fact that your memory is based on your recollection of the gist of the list you saw and not the actual list: the word “sweet” was not on the list, but most of the words on the list were related thematically to the concept of sweetness. The memory researcher Daniel Schacter wrote that he gave tests like this to many audiences and the great majority of people claimed that “sweet” was on the list, even though it was not.¹⁸ I have also given this test to many large groups, and while I did not find a great majority remembering that “sweet” was on the list, I did consistently get about half of my audience claiming it was—about the same number who correctly recalled that “taste” was on it. That result was consistent across many cities and countries. The difference between my results and Schacter’s may stem from the way I phrase the question—for I always stress that people should not designate a word unless they are sure, unless they can picture the list and vividly see that the word is on it.

Our process of remembering can be said to be analogous to the way computers store images, except that our memories have the added complexity that the memory data we store changes over time—we’ll get to that later. In computers, to save storage space, images are often highly “compressed,” meaning that only certain key attributes of the original image are kept; this technique can reduce the file size from megabytes to kilobytes. When the image is viewed, the computer predicts, from the limited information in the compressed file, what the original image looked like. If we view a small “thumbnail”-sized image made from a highly compressed data file, it usually looks very much like the original. But if we blow the image up, if we look closely at the details, we see many errors—blocks and bands of solid color where the software guessed wrong and the missing details were incorrectly filled in.

That’s how both Jennifer Thompson and John Dean got fooled, and it’s essentially the process Munsterberg envisioned: remember the gist, fill in the details, believe the result. Thompson recalled the “gist” of her rapist’s face, and when she saw a man in the lineup of photographs who fit the general parameters of what she remembered, she filled in the details of her memory with the face of the man in front of her, working off the expectation that the police wouldn’t show her a set of pictures unless they had reason to believe the rapist’s photo was among them (though as it turned out, it wasn’t). Similarly, Dean remembered few of the details of his individual conversations, but when he was pressed, his mind filled them in, using his expectations about what Nixon would have said. Neither Thompson nor Dean was aware of those fabrications. And both had them reinforced by repeatedly being asked to relive the events they were remembering, for when we are repeatedly asked to re-create a memory, we reinforce it each time, so that in a way we are remembering the memory, not the event.

You can easily see how this happens in your own life. Your brain, for example, might have recorded in its neurons the feeling of being embarrassed when you were teased by a fourth-grade boy because you brought your favorite teddy bear to school. You probably wouldn’t have retained a picture of the teddy bear, or the boy’s face, or the look on that face when you threw your peanut butter sandwich at him (or was it ham and cheese?). But suppose that years later you had reason to relive the moment. Those details might then have come to mind, filled in by your unconscious. If, for some reason, you returned to the incident again and again—perhaps because in retrospect it had become a funny story about your childhood that people always enjoyed hearing—you most likely created a picture of the incident so indelibly vivid and clear to yourself that you would believe totally in the accuracy of all the details.

If this is so, you may be wondering, then why have you never noticed your memory mistakes? The problem is that we rarely find ourselves in the position that John Dean was in—the position of having an accurate recording of the events we claim to remember. And so we have no reason to doubt our memories. Those who have made it their business to investigate memory in a serious fashion, however, can provide you with plenty of reasons for doubting. For example, the psychologist Dan Simons, ever the scientist, became so curious about his own memory errors that he picked an episode from his own life—his experiences on September 11, 2001—and did something few of us would ever make the effort to do.¹⁹ He investigated, ten years later, what had actually happened. His memory of that day seemed very clear. He was in his lab at Harvard with his three graduate students, all named Steve, when they heard the news, and they spent the rest of the day together, watching the coverage. But Simons’s investigation revealed that only one of the Steves was actually present—another was out of town with friends, and the third was giving a talk elsewhere on campus. As Munsterberg might have predicted, the scene Simons remembered was the scene he’d have expected, based on prior experience, since those three students were usually in the lab—but it wasn’t an accurate picture of what happened.

THROUGH HIS LOVE of case studies and real-life interactions, Hugo Munsterberg advanced the frontiers of our understanding of how we store and retrieve memories. But Munsterberg’s work left open a major issue: How does memory change over time? As it turned out, at about the same period when Munsterberg was writing his book, another pioneer, a laboratory scientist who, like Munsterberg, swam against the Freudian tide, was studying the evolution of memory. The son of a shoemaker from the tiny country town of Stow-on-the-Wold in England, the young Frederic Bartlett had to take over his own education when the town’s equivalent of a high school closed.²⁰ That was in 1900. He did the job well enough that he ended up an undergraduate at Cambridge University, where he remained for graduate school; he eventually became the institution’s first professor in the new field of experimental psychology. Like Munsterberg, Bartlett did not go into academia planning to study memory. He came to it through an interest in anthropology.

Bartlett was curious about the way culture changes as it is passed from person to person, and through the generations. The process, he thought, must be similar to the evolution of an individual’s personal memories. For example, you might remember a crucial high school basketball game in which you scored four points, but years later, you might remember that number as being fourteen. Meanwhile, your sister might swear you spent the game in a beaver costume, dressed as the team’s mascot. Bartlett studied how time and social interactions among people with differing recollections of events change the memory of those events. He hoped, through that work, to gain an understanding of how “group memory,” or culture, develops.

Bartlett imagined that the evolution of both cultural and personal memories resembles the whisper game (also called the telephone game). You probably recall the process: the first person in a chain whispers a sentence or two to the next person in the chain, who whispers it to the next person, and so on. By the end, the words bear little resemblance to what was said at the beginning. Bartlett used the whisper game paradigm to study how stories evolve as they pass from one person’s memory to the next. But his real breakthrough was to adapt the procedure to study how the story can evolve over time within an individual’s memory. Essentially, he had his subjects play the whisper game with themselves. In his most famous work, Bartlett read his subjects the Native American folktale “The War of the Ghosts.” The story is about two boys who leave their village to hunt seals at the river. Five men in a canoe come along and ask the boys to accompany them in attacking some people in a town upriver. One of the boys goes along, and, during the attack, he hears one of the warriors remark that he—the boy —had been shot. But the boy doesn’t feel anything, and he concludes that the warriors are ghosts. The boy returns to his village and tells his people about his adventure. The next day, when the sun rises, he falls over, dead.

After reading the story to his subjects, Bartlett asked them to remind themselves of the tale after fifteen minutes, and then at irregular intervals after that, sometimes over a period of weeks or months. Bartlett studied the way that his subjects recounted the stories over time, and he noted an important trend in the evolution of memory: there wasn’t just memory loss; there were also memory additions. That is, as the original reading of the story faded into the past, new memory data was fabricated, and that fabrication proceeded according to certain general principles. The subjects maintained the story’s general form but dropped some details and changed others. The story became shorter and simpler. With time, supernatural elements were eliminated. Other elements were added or reinterpreted so that “whenever anything appeared incomprehensible, it was either omitted or explained” by adding content.²¹ Without realizing it, people seemed to be trying to alter the strange story into a more understandable and familiar form. They provided the story with their own organization, making it seem to them more coherent. Inaccuracy was the rule, and not the exception. The story, Bartlett wrote, “was robbed of all its surprising, jerky and inconsequential form.”

This figurative “smoothing out” of memories is strikingly similar to a literal smoothing out that Gestalt