A good example of how malleable memory can be comes from Psychologist Ulric Neisser, a professor at Emory University in January 1986 when the space shuttle Challenger blew up just after lift off. The day after the disaster, he conducted an experiment in which he gave students in his freshman psychology class a questionnaire about the explosion.
After three years he sought them out and administered the exact same questionnaire, except with the addition that he asked them how reliable they thought their memories were. This was an excellent opportunity to test memory here were intelligent students who were exposed to a dramatic event which they should remember well. They had no reason at all to lie, and this was one of those events about which people say You will always remember where you were and what you were doing.
So, how well did the students remember? According to Neisser, only 10% matched their earlier responses and a full quarter of students did not have one memory of the event which proved to be accurate. Considering the following two reports from the same student:
- January 1986: I was in my religion class and some people walked in and started talking about the [explosion]. I didnt know any details except that it had exploded and the schoolteachers students had all been watching, which I thought was so sad. Then after class I went to my room and watched the TV program talking about it and I got all the details from that.
- September 1988: When I first heard about the explosion I was sitting in my freshman dorm room with my roommate and we were watching TV. It came on a news flash and were we both totally shocked. I was really upset and went upstairs to talk to a friend of mind and then I called my parents.
Self-reports of reliability were no indication of accuracy those who had inaccurate reports were just as likely to be confident as students whose memories were unchanged. Even more interesting was the students reactions to the discrepancies. None denied the accuracy of the original statements but, according to one, I still remember everything happening the way I told you. I cant help it.
The statements in the second batch of questionnaires were all made sincerely and honestly. The students faithfully reported what they remember. And, in most cases, they were wrong either often or in every detail. How could these errors occur? A common reason is the influence of others reports. Over time, people can readily confabulate their own memories with the reports of others, in the end producing something entirely new, entirely different, and entirely honest.
It is because of this phenomenon that those who question witnesses are supposed to work very hard not to ask leading questions such questions can readily create certain expectations in a witness and cause their memory of events to be altered. Witnesses are also asked not to compare notes with each other because this, too, can cause their memories to shift and change, resulting in an inaccurate picture.
If eyewitness testimony and memory can be so unreliable, why do people continue to rely upon them so much? There are a couple of factors which play an important role. For one thing, most people are simply unaware of how unreliable testimony and memory can be popular perceptions are very different from fact.
Another factor is that admitting to the unreliability of the testimony and memory of someone else may mean admitting that ones own testimony and memory may be unreliable and who wants to do that? Finally, to not believe someone else would entail, at least it is so assumed, accusing the speaker of lying. Most people dont want personal confrontation and they certainly dont want to accuse someone else of lying, especially when they sound and act so sincere.
None of that, however, need be the case. Refusing to believe someones personal testimony about an event which happened to them does not require you to call them a liar. A person doesnt have to be dishonest in order to give inaccurate reports about things which happened. Remember the quote from above: even honest testimony can be less than completely credible. We must all accept that our memories are not as accurate as we would like to think and, as a result, our testimony about events is not as accurate as we would like to think.