東大 ２０１８年 問題１B
以下の英文を読み、Jonathan Schooler らが発見したと言われていることの内容を、１５~２０語程度の英語で要約せよ。文章から答えを抜き出すのではなく、できるだけ自分の英語で答えよ。
When we think back on emotional events from the past, our memories tend to be distorted by internal influences. One way this can happen is through sharing our memories with others, something that most of us are likely to do after important life events — whether it's calling our family to tell them some exciting news, reporting back to our boss about a big problem at work, or even giving a statement to police. In these kinds of situations we are transferring information that was originally received visually (or indeed through other senses) into verbal information. We are turning inputs from our five senses into words. But this process is imperfect; every time we take images, sounds, or smells and verbalise them, we potentially alter or lose information. There is a limit to the amount of detail we are able to communicate through language, so we have to cut corners. We simplify. This is a process known as "verbal overshadowing," a term invented by psychologist Jonathan Schooler.
Schooler, a researcher at the University of Pittsburgh, published the first set of studies on verbal overshadowing in １９９０ with his colleague Tonya Engstler-Schooler. Their main study involved participants watching a video of a bank robbery for ３０ seconds. After then doing an unrelated task for ２０ minutes, half of the participants spent five minutes writing down a description of the bank robber's face, while the other half undertook a task naming countries and their capitals. After this, all the participants were presented with a line-up of eight faces that were, as the researchers put it, "verbally similar," meaning that the faces matched the same kind of description — such as "blonde hair, green eyes, medium nose, small ears, narrow lips." This is different from matching photos purely on visual similarity, which may focus on things that are harder to put into words, such as mathematical distances between facial features.
We would expect that the more often we verbally describe and reinforce the appearance of a face, the better we should retain the image of it in our memory. However, it seems that the opposite is true. The researchers found that those who wrote down the description of the robber's face actually performed significantly worse at identifying the correct person out of the line-up than those who did not. In one experiment, for example, of those participants who had written down a description of the criminal, only ２７ percent picked the correct person out of the line-up, while ６１ percent of those who had not written a description managed to do so. That's a huge difference. By stating only details that could be readily put into words, the participants had overlooked some of the details of their original visual memory.
This effect is incredibly robust, as indicated by the outcome of possibly the biggest effort ever to reproduce the result of an experiment in psychology. This was a massive project by ３３ labs and almost １００ scholars, including Jonathan Schooler and Daniel Simons, published in ２０１４. All researchers followed the same methods, and they found that even when the experiment was conducted by different researchers, in different countries, and with different participants, the verbal overshadowing effect was constant. Putting pictures into words always makes our memories of those pictures worse.
Further research by Schooler and others has suggested that this effect may also transfer to other situations and senses. It seems that whenever something is difficult to put into words, verbalisation of it generally diminishes recall. Try to describe a colour, taste, or melody, and you make your memory of it worse. Try describing a map, a decision, or an emotional judgement, and it becomes harder to remember all the details of the original situation. This is also true when others verbalise things for us. If we hear someone else's description of something we have seen, our memory of it is weakened in that case too. Our friends may be trying to help us when they give their verbal account of something that happened, but they may instead be overshadowing our own original memories.
According to Schooler, besides losing details, verbalising non-verbal things makes us generate competing memories. We put ourselves into a situation where we have both a memory of the time we described the event and a memory of the time we actually experienced the event. This memory of the verbalisation seems to overwhelm our original memory fragment, and we may subsequently remember the verbalisation as the best account of what happened. When faced with an identification task where we need all the original details back, such as a photo line-up, it then becomes difficult to think past our verbal description. In short, it appears our memories can be negatively affected by our own attempts to improve them.
This does not mean that verbalising is always a bad idea. Schooler's research also shows that verbalising our memories does not diminish performance – and may even improve it — for information that was originally in word form: word lists, spoken statements, or facts, for example.