Novelty also helps in getting something into memory. Psychologists have found that people can usually give a detailed accounting of what happened at work the day before. But one week later most of the details are gone and in its place is an account of what happens on a typical workday. People guess, in other words. The problem here is what Daniel Schacter calls “interference.” What you did Monday is similar to what you did on Tuesday and the other workdays, so when you try to recall what you did on Monday a week later, experiences from the other workdays interfere. But if Monday had been your last day of work before going on vacation, you would have much better recall of that day a week later because it would be more unusual.
Concentration and repetition also boost memory. If you see something—anything—and don’t give it a second thought, there’s a good chance it will never encode in memory and will vanish from your consciousness as if it had never happened. But if you stop and think about it, you make the memory a little stronger, a little more lasting. Do it repeatedly and it gets stronger still. Students do this when they cram for exams but the process can be much more informaclass="underline" Even a casual conversation at the watercooler will have the same effect because it, too, calls the memory back into consciousness.
There is obvious survival value in remembering personal experiences of risk. But even more valuable for our ancient ancestors—and us, too—is the ability to learn and remember from the experiences of others. After all, there’s only one of you. But when you sit around the campfire after a long day of foraging, there may be twenty or thirty other people. If you can gather their experiences, you will multiply the information on which your judgments are based twenty or thirty times.
Sharing experiences means telling stories. It also means visualizing the event the guy next to you at the campfire is telling you about: imagining the dimmest member of the tribe wading into the shallow waters of the river; imagining him poking a floating log with his walking stick; imagining the log suddenly turning into a crocodile; imagining the trail of bubbles that marks the demise of the tribe’s dimmest member. Having envisioned the scene and committed it to memory, Gut can then use it to make judgments just as it uses memories from personal experiences. Risk of crocodile attack at water’s edge? Yes. You can recall just such an incident. Chance that the log floating out there isn’t what it appears? Considerable—that incident was easily recalled. You may not be consciously aware of any of this analysis, but you will be aware of the conclusion: You will have a feeling—a sense, a hunch—that you really shouldn’t go any closer. Gut has learned from someone else’s tragic experience.
But not all imagined scenes are equal. An event that comes from a story told by the person who actually experienced it provides valuable, real-world experience. But an imagined scene that was invented by the storyteller is something else entirely. It’s fiction. Gut should treat it accordingly, but it does not.
One of the earliest experiments examining the power of imagination to sway intuition was conducted during the U.S. presidential election campaign of 1976. One group was asked to imagine Gerald Ford winning the election and taking the oath of office, and then they were asked how likely it was that Ford would win the election. Another group was asked to do the same for Jimmy Carter. So who was more likely to win? Most people in the group that imagined Ford winning said Ford. Those who saw Jimmy Carter taking the oath said Carter. Later experiments have obtained similar results. What are your odds of being arrested? How likely is it you’ll win the lottery? People who imagine the event consistently feel that the odds of the event actually happening are higher than those who don’t.
In a more sophisticated version of these studies, psychologists Steven Sherman, Robert Cialdini, Donna Schwartzman, and Kim Reynolds told 120 students at Arizona State University that a new disease was increasingly prevalent on campus. The students were split into four groups. The first group was asked to read a description of the symptoms of the new disease: low energy level, muscle aches, headaches. The second group was also asked to read the symptoms, but this time the symptoms were harder to imagine: a vague sense of disorientation, a malfunctioning nervous system, and an inflamed liver. The third group was given the easily imaginable list of symptoms and asked to imagine in great detail that they had the disease and were experiencing the symptoms. The fourth group received the hard-to-imagine symptoms and was asked to imagine they had the disease. Finally, all four groups were asked to answer a simple question: How likely is it that you will contract the disease in the future?
As expected, the students who got the easy-to-imagine symptoms and who imagined themselves contracting the disease rated the risk highest. Next came the two groups who did not do the imagining exercise. The lowest risk estimate came from those who got the hard-to-imagine symptoms and did the imagining exercise. This proved something important about imagining: It’s not merely the act of imagining that raises Gut’s estimate of how likely something is, it’s how easy it is to imagine that thing. If imagining is easy, Gut’s estimate goes up. But if it is a struggle to imagine, it will feel less likely for that reason alone.
It may be a little surprising to think that the act of imagining can influence our thoughts, but in many different settings—from therapy to professional sports—imagining is used as a practical tool whose effectiveness is just as real as the famous placebo effect. Imagination is powerful. When the ads of lottery corporations and casinos invite us to imagine winning—one lottery’s slogan is “Just Imagine”—they do more than invite us to daydream. They ask us to do something that elevates our intuitive sense of how likely we are to win the jackpot—which is a very good way to convince us to gamble. There is no “just” in imagining.
This isn’t the only potential problem with Gut’s use of the Example Rule. There’s also the issue of memory’s reliability.
Most people think memory is like a camera that captures images and stores them for future retrieval. Sure, sometimes the camera misses a shot. And sometimes it’s hard to find an old photo. But otherwise, memory is a shoebox full of photos that directly and reliably reflect reality.
Unfortunately, this isn’t even close to true. Memory is better described as an organic process. Memories routinely fade, vanish, or transform— sometimes dramatically. Even the strongest memories—those formed when our attention is riveted and emotions are pumping—are subject to change. A common experiment memory researchers conduct is tied to major news, such as the September 11 terrorist attacks. In the days immediately following these spectacular events, students are asked to write how they heard about it: where they were, what they were doing, the source of the news, and so on. Years later, the same students are asked to repeat the exercise and the two answers are compared. They routinely fail to match. Often the changes are small, but sometimes the entire setting and the people involved are entirely different. When the students are shown their original descriptions and are told that their memories have changed, they often insist their current memory is accurate and the earlier account is flawed—another example of our tendency to go with what the unconscious mind tells us, even when doing so is blatantly unreasonable.