About ten years ago at a party Dan hosted, a colleague of ours named Ken Norman told us a funny story about sitting next to the actor Patrick Stewart (best known for his roles as Captain Jean-Luc Picard of Star Trek and Charles Xavier in the X-Men films) at a Legal Sea Food restaurant in Cambridge, Massachusetts. The story was prompted when Chris noticed that Dan had a small figurine of Captain Picard perched next to his television screen. “Can I buy your Captain Picard?” asked Chris. Dan said that it was not for sale. Chris offered five, then ten dollars. Dan refused. Chris eventually raised his bid to fifty dollars—for reasons that escape him now—but Dan still refused. (Neither of us remembers why Dan refused, but to this day, Picard has not left his place amid Dan’s electronics.)
At this point Ken told us that at Legal Sea Food, Patrick Stewart had been dining with an attractive younger woman who, based on snippets of overheard conversation, appeared to be a publicist or agent. For dessert Stewart ordered Baked Alaska—a choice that stood out in memory because it appears rarely on restaurant menus. Toward the end of his meal, another distinctive event happened: Two members of the kitchen staff came out to Stewart’s table and asked for his autograph, which he readily granted. Moments later, a manager appeared and apologized, explaining that the “Trekkie” cooks’ action was against restaurant policy. Stewart shrugged off the supposed offense, and he and his companion were soon on their way.
The only problem with the story was that it had actually happened not to Ken, but to Chris. Ken had heard Chris tell the story some time before and had incorporated it into his own memory. In fact, Ken felt so strongly that the memory was his, and had so completely forgotten that Chris was the original raconteur, that even Chris’s presence when Ken retold the story did not jog his memory of the way in which he had actually “encountered” Captain Picard. But when Chris pointed out the error, Ken quickly realized that this memory was not his own. This anecdote illustrates another aspect of the illusion of memory: When we retrieve a memory, we can falsely believe that we are fetching a record of something that happened to us rather than someone else.
Although we believe that our memories contain precise accounts of what we see and hear, in reality these records can be remarkably scanty. What we retrieve often is filled in based on gist, inference, and other influences; it is more like an improvised riff on a familiar melody than a digital recording of an original performance. We mistakenly believe that our memories are accurate and precise, and we cannot readily separate those aspects of our memory that accurately reflect what happened from those that were introduced later. That’s how Ken appropriated Chris’s story — he had a vivid memory for the event, but mistakenly attributed it to his own experience. In the scientific literature, this type of distortion is known as a failure of source memory. He forgot the source of his memory, but because it was so vivid, he assumed that it came from his own experience.
This is an extract from Christopher Chabris and Daniel Simons' The Invisible Gorilla published by Harmony