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The Reality of False Memories
From: Columbia University
| By:
Elizabeth Loftus |
EDITOR'S INTRODUCTION |
False memories of childhood sexual abuse have wrecked families, destroyed individual lives and even led to imprisonment for those wrongly accused. Elizabeth Loftus, professor of psychology and adjunct professor of law at the University of Washington, argues that these false memories dilute the claims of actual victims and hurt the psychiatric profession as a whole. She conducted a series of experiments with colleagues that show how suggestion has the power to help plant false memories in people and how people often construct narratives from these planted memories which then take on a reality of their own. |
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| False memories can be introduced in counseling. | |
 uman memory can readily become distorted through leading questions or suggestive or coercive interviewing. Memory distortion even occurs in therapy. In the 1990s, courts had to face lawsuits based on false memories of sexual molestation. The challenge for psychologists, as a result, was to figure out how to demonstrate the capacity to plant an entirely false, traumatic memory in someone's mind. |
Psychologists who are connected with any university or college have a formidable obstacle to overcome before conducting scientific research: the human-subjects review committee. Obviously, even in the name of science, psychologists cannot harm subjects; we could not try to plant memories of sexual abuse in subjects--but perhaps there was some other kind of memory we could try to plant. |
Planting a false memory of getting lost
Some of my graduate students went through relevant literature and came up with an idea: "Why don't we try to convince people that when they were about 5 years old they were lost, frightened and crying in a shopping mall until they were ultimately rescued by an elderly person and reunited with their family?" Admittedly, the scenario is not as severe as sex abuse, but it gave us an at least mildly traumatic event that we could try to plant. |
My graduate students and I worked with pairs of relatives in this study: a younger member of the pair, who was the subject of the study, and the subject's older brother or mother or father. We told the subject, "We have talked to your older brother [or mother or father], and we found out some things that happened to you when you were 5 years old. We would like to see if you remember these experiences and what you remember about them." |
We presented the subject with three events that had actually happened when the subject was about 5 years old and also with the event (about getting lost and then rescued) that we had crafted with the help of the older relatives. We presented these memories as if they were all true, and we encouraged the subject to try to recall the experience. |
One of our subjects was a Vietnamese-American named Tran. She received the suggestion that when she was 5 years old she got lost with her brother and sister in a K Mart in Bremerton, Washington. She was found crying by an elderly Chinese woman, and was reunited with her family. Over the course of three successive interviews, Tran began to "remember" more and more about this experience. Finally--and this is actually verbatim from her tape-recorded interview--she said, "When I got lost, I went to the shoe department, because we used to like to buy shoes and stuff. So after I got lost, I thought, OK, well, maybe everyone went back there; so I went back to the shoe department and I looked down all the aisles and I was crying. I was really young." When the recollection does get produced, it can be a very detailed and elaborated narrative. |
I published this study with my graduate student Jackie Pickerel (who is really a master memory planter, although her percentages have been outdone by subsequent investigators). We claimed we had shown that a significant minority--about 25 percent--could be led to produce details about a falsely planted event. |
When I first began to speak about this study at scientific meetings, people loved to hate it. Why? People fumed, "How dare you talk about being lost in the same breath as being sodomized?" A gentler reaction that still makes the same point was "Why don't you at least show that you can plant memories for something a little bit more bizarre or unusual?" |
Planting other false memories
The first group to take up the challenge to produce a bizarre and false memory was a group lead by Ira Hyman, associate professor of psychology at Western Washington University. He used a procedure that was very similar to the one we had used. He asked relatives to provide information about a younger relative, and then suggested to the younger relative some events that had truly happened, as well as an event that had not happened. In this study, the false event was that, at a younger age, the subject stayed overnight at a hospital for an investigation of a horrible ear pain and possible ear infection. |
The Hyman research group conducted another study. This time, the suggestion to the subject was that, as a child at a family wedding, the subject accidentally spilled a bowl of punch all over the parents of the bride. After three suggestive interviews, 25 percent of Hyman's adult sample had bought into all or part of that suggested memory--and often elaborated on it. |
Along with Steven Ceci, professor of developmental psychology at Cornell, Maggie Bruck, visiting professor of child psychiatry at Johns Hopkins University, Michelle Leichtman, associate professor of psychology at Harvard, and others, I worked on similar studies with children who were 3 to 6 years old. Using a variety of techniques, we suggested to these subjects that, when they were younger, they had various unusual experiences. One suggestion was that the child's hand got caught in a mousetrap and the child had to go to the hospital to get the mousetrap removed. Of the 3- and 4-year-olds, 35 to 40 percent bought into all or part of this suggested memory. These children even supplied additional details, such as where the mousetrap was, what it was next to, and who went with them to the hospital. Again, the recollections were sometimes very elaborate. |
Recently, Law and Human Behavior published Stephen Porter's doctoral dissertation from the University of British Columbia, which shows the most recent version of memory planting using the method that I have described. Porter attempted to plant memories of vicious animal attacks that happened when the subjects were children. All I can say is that in terms of methodology, he must have been doing something better or more effectively than the rest of us who were researching false memory planting: Porter showed that partially or completely false memories could be planted in about 50 percent of his sample. |
In 1999, Law and Human Behavior published an article by Stephen Porter, John Yuille and Darrin Lehman called "The Nature of Real, Implanted, and Fabricated Memories for Emotional Childhood Events," which reported a condensed version of Porter's doctoral dissertation. In it, Porter discusses making an attempt at sorting out differences between true memories that people actually had (which are a result of their own perception) and false memories (which are a result of suggestion). False-memory planting is now incorporated into an active paradigm for memory distortion. |
The power of suggestion in planting false memories
I have heard many therapists complain that the studies in false-memory planting do not demonstrate what occurs in therapy. They complain that having a family member claim to have witnessed an event is a strong form of suggestion; not having been in their patients' early lives, therapists cannot and do not say anything quite as powerful or suggestive as the method used in the research for false-memory planting. My response is that, in planting false memories, we are just showing the power of suggestion. |
Therapy techniques that may plant false memories
I want to move to what I think are more frequently used and more subtly suggestive techniques for planting memories, which have an even more insidious impact because of their subtlety. |
If you want to know what kinds of things are going on in some psychotherapy sessions, read the books in the incest book industry--popular books that are written by mental-health professionals for their colleagues or patients. Some of these books contain descriptions of techniques certain psychotherapists like to use in their psychotherapy. One technique is imagistic work; dream work is another. |
Imagistic work is used when a patient claims no memories of sexual abuse but demonstrates symptoms of it. The basic suggestion behind imagistic work is: "Why don't you just close your eyes and try to imagine who might have sexually abused you? I don't know ... maybe Daddy? How old might you have been? Where might this have happened?" |
I wondered what the effect would be of getting people to imagine that they had had an experience that they didn't have. In order to find out, Maryanne Garry (my postdoctoral student), Chuck Manning (my graduate student), Jim Sherman (a social psychologist at Indiana University) and I designed a study on imagination and the power of imagination. |
Studying the power of imagination
I am going to walk you through this imagination study. I want you to see what the method is, because we are going to be using some of the same material in our new studies on dream interpretation, and you will be able to follow the new studies more smoothly. |
First, we gave people a "life events inventory"--something that we constructed and called the LEI. It asks questions about childhood and asks what level of confidence the subject had that an event had actually occurred before the subject was 10 years old. (The scale ranges from an event definitely not having happened to definitely having happened.) Two weeks later, people again took the LEI. Between these two administrations of the LEI, we asked some of our subjects to imagine that they had had certain experiences while other subjects imagined different experiences. Certain critical items were embedded into the LEI. One example is that a subject broke a window with his or her hand. Subjects assigned to the imagination group were asked to imagine that they are playing outside after school. They hear a strange noise that makes them run to the window to see what made the noise. As they are running, they trip and fall. |
Afterward, to make sure that they were involved in this imagination exercise, we asked these subjects a few questions, such as what they tripped on and if they were alone. Their response was their own construction. We continued the imagination by elaborating the scenario: "When you reach out and catch yourself as you are falling, your hand goes through the window, and you get cut and bleed. Stop and imagine that." It takes about a minute. A little while after this imagination exercise, the subjects in this group will take the LEI again. |
Now, these subjects have taken the LEI twice--obviously, they can give the same answer both times. Giving the same answer both times is the most common thing that people did, although they could have increased or decreased their confidence that they had had a certain experience. |
Some subjects, however, experience an "imagination inflation"--the increased confidence that one had an experience as a child, which is caused by the act of imagination. In the case of this particular study, imagination inflation is a small effect, but it is a consistent effect--every single one of our critical items showed that increase in confidence after a single act of imagination. |
Who is susceptible to false memories?
Some of the questions that those of us who study false-memory planting are often asked are: Who is susceptible to these kinds of manipulations? Are some of us more susceptible than others? My opinion is that these kinds of influences can affect all of us. There are, however, some individual differences that can predict who is more susceptible. |
Let me just show you one example. Along with Dr. John Paddock, a clinical psychologist in Georgia, I looked into the Dissociative Experiences Scale (DES), a measure of lapses in memory and attention. This instrument is common in clinical assessment and is used in research. It asks questions such as: How often (on a scale from 0 percent of the time to 100 percent of the time) do you suddenly, once you've arrived at your workplace, have no recollection of the route getting there? How often do you fail to remember whether you said something or just thought about saying that thing? The score reflects your self-reported lapses in memory and attention. |
Paddock and I actually did an imagination-inflation study using the same kind of methodology as the imagination study--subjects tell of their childhood on two occasions, and between the two occasions some subjects imagine having had certain experiences and others do not. |
Does the size of that effect relate to the subjects' dissociative-experiences score? Yes, there is a significant correlation. People who have more lapses in memory and attention are more susceptible to having imagination affect their autobiography. Why is this important? Many of the people in psychotherapy happen to score high on the DES. Problems related to false-memory planting may result from certain people encountering the suggestive influences they are susceptible to. |
Dream interpretation's contribution to planting false memories
In addition to imagistic work, I want to tell you about another exciting area: our new work on dream interpretation. If you have ever been in or done therapy, you know that dream material is often discussed. It is important to recognize that day residue gets into dreams--what you're worried about during the day may materialize in the form of dream material at night. There's certainly nothing wrong with using dreams as a starting point for some discussion. What may be objectionable is when the dream material is interpreted to mean something without a basis for that interpretation. |
My contact with dream material and dream interpretation in the real world comes from the litigation that I have been involved in as a memory expert testifying in criminal cases that involve eyewitness testimony based on memory. As a result of this litigation, I have had a chance to examine hundreds of these cases and their accompanying medical records. I can tell you that if a patient dreams about a snake, the snake represents a penis. But when I got my first case, where the patient dreamt about a cinnamon roll and the therapist told her that it represented a penis, I thought this was going too far. Eventually I was able to find out that the link for the therapist was the goo on the cinnamon roll, so there was some basis, I suppose, for this interpretation. But, what happens when a therapist--the "expert"-- takes dream material and tells a patient, "This dream material means that you had an illicit experience when you were younger." |
Dream interpretation's ability to contaminate autobiography
Along with Giuliana Mazzoni at the University of Florence and some of our collaborators, I have been looking at the ability of dream interpretation to contaminate autobiography. First of all, one of the things I really like about this experiment, which is a series of studies, is that in some of this work a question comes up about the demand characteristics of the situation. In the imagination studies, people who have imagined that they put their hand through a window are now asked about their childhoods--in particular, whether they broke a window with their hands. The subjects may figure out the experiment. They may consider the situation to be one where the experimenter expects them to give a higher score, and they decide to comply to make the experimenter feel good by conforming to what they think is the experimental hypothesis. That is always a possibility. We try to rule out those kinds of processes, but we may not be entirely successful. |
In this dream work, we came up with a method that I think effectively rules out demand characteristics as any kind of explanation for our data. How did we do it? We disguised our study so that the subjects think they are participating in two completely unrelated studies. The first is the early-memory experiment, where they fill out a life event inventory telling us about their childhood, which they will fill out again three to four weeks later. Perhaps they just think the experiment is something about consistency or whatever. Unbeknownst to these subjects, however, half of them are lured across town to participate in another study: the sleep and dream experiment. |
When subjects sign up for the sleep and dream experiment, they are supposed to show up at a therapist's office with a dream report--whether it be last night's dream, a very vivid dream, a recurring dream, whatever. They hand the dream report to our collaborator, Dr. Lombardo, who is the Dr. Laura of Florence (this study was conducted in Italy). He does not entertain her controversial issues, but he is a radio psychologist. He is well known, articulate, charismatic. |
Once Dr. Lombardo gets the dream report, he talks to the subject about what the dream means to the subject. He establishes the fact that he has a lot of experience with dream interpretation and is one of the world's experts. Dr. Lombardo tells them that dreams do tap into early experiences in life; he feeds them biased information. No matter what the patient has dreamed, he tells the subject, "What your dream means is that before you were 3 years old, you were lost in a big public place for an extended period of time, and you felt abandoned by your parents. You felt lonely and lost in this unfamiliar place. You know, it turns out that the last patient I had who actually dreamt the same kind of dream you did had been lost for about an hour and a half in a piazza." This session continues for half an hour. |
Results from the dream interpretation study
One to two weeks after the dream interpretation session, the subjects fill out the LEI for the second time. Here are the results:
- 89 percent of these subjects increased their confidence that they were lost in a public place.
- 58 percent felt abandoned by their parents before they were 3 years old. (This is almost the equivalent to the imagination inflation at work here.)
- 79 percent increased confidence that they found themselves lonely and lost in an unfamiliar place.
On an eight-point scale, the mean increase in confidence is 2.25 points. |
Meanwhile, there is no change in performance or confidence level for those who did not get the dream interpretation. This dream interpretation process actually produces whopping suggestive effects. |
Replication of the dream interpretation study
The first thing that Mazzoni and I wanted to do was to try to replicate this study. As you do with a replication, we decided that part of it would be a pure replication. We exposed 50 percent of our subjects to the dream interpretation that when they were younger they felt lost and abandoned, but, in order to learn more about the phenomenon, we added some new things. The other 50 percent of our subjects had their dream interpreted to mean that, before they were 3 years old, they faced a great danger, a threat to their life, from which they were then rescued. Wondering how long the effects of dream interpretation would last, we also decided to increase the time interval between the dream interpretation and the second administration of the LEI to one month. |
Results from the replication study
Every single one of these subjects showed increased confidence. Here are the results of the replication set:
- 75 percent increased confidence that they were abandoned by their parents.
- 82 percent increased confidence that they were lonely and lost in an unfamiliar place.
The results from the danger set follow:
- 68 percent increased their confidence that they faced a great danger before the age of 3.
- 66 percent increased confidence that they faced a threat to their lives.
- 51 percent said they were rescued from a dangerous situation.
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On the eight-point scale, there is virtually no change in the performance of controlled data, where there is no dream interpretation relevant to the items. |
Instead of going into the details of our subsequent studies, I will tell you that my collaborators and I have replicated this study at the University of Washington. Lombardo did not fly out to conduct the study; Mazzoni herself did half the dream interpretations. Whereas we had thought that we really needed Lombardo or somebody very charismatic and persuasive for the dream interpretations, it turns out we did not. We trained a rather charismatic recent graduate to do the other half of the dream interpretations--and he was equally effective, after just a little bit of training from Mazzoni, in creating the same sorts of results. |
Locating factors for increased confidence
We have also answered a further question about this work. When subjects walk out of the office of the therapist or the dream interpreter, they are really saying, "I don't remember anything like that, but it sounds plausible." It's not as if they have a full-blown memory from the minute after they hear a dream interpretation. Yet, two to four weeks later, they are telling us they have increased confidence in an event's occurrence. What is it that they actually have? Have they developed a concrete narrative episodic memory by that point, or do they just have a belief that states, "I know this happened to me, though I do not have any concrete memories of it"? |
As it turns out, about 50 percent of these subjects end up developing some concrete narrative, and the other 50 percent had what we just call a belief that an event was their experience. |
Debriefing the subject after the experiment
We always, of course, debrief the subjects at the end of an experiment. Whenever you are doing an experiment that involves deception, it is very important to spend a lot of time thinking about how to do the debriefing. In virtually all of our studies, we do our debriefing by telling people that their behavior is very normal. (We try not to make subjects feel like saps about having succumbed to a suggestion, if they did.) We have never had a bad experience. I speculate that there are probably people who, after the debriefing, still wonder if the experience is true. We have had anecdotal reports of people going back to their parents, for example, saying, "I really think I was lost, and are you sure that that was just made up?" I can't say that the debriefing totally wipes out the manipulation, but we do take pains to do it well. |
I will tell you one anecdotal story--you will never hear this anywhere else--about one subject in the dream interpretation study. Mazzoni was doing the dream interpretations in a dimly lit office down the hall from my office. After finishing a dream interpretation with a particular subject--and remember, subjects are not going to get debriefed for another several weeks, because they have to complete the LEI--she told me that she was really upset about the way this particular dream interpretation went. When it was done, the subject thanked her profusely and said, "I finally think I understand myself. I finally really feel I have some insight into why I feel the way I do." |
After having been told that she had been lost and felt abandoned, the subject felt new understanding--but she was going to be debriefed in two weeks. We asked ourselves whether there were any additional steps that we should be taking to be extra careful with her. Mazzoni made sure she was present for that debriefing and that she handled it personally. As it turned out, the subject was fine with the idea. In fact, all the subjects were fascinated by the whole experiment. |
Implications of false-memory planting
I think that these results have many implications for the study of memory. In The Myth of Repressed Memory, which Kathy Ketcham and I co-authored, we invite readers to think of the mind as a bowl filled with clear water. Now, imagine each memory as a teaspoon of milk stirred into the water. When you do this stirring, and then I say we have to pluck these memories out, well, it's all spread through this watery mix. How do you disentangle the water from the milk after it's already in there? It's a very interesting process to think about. I think that these results can tell us about the hundreds, if not thousands, of people in our society who have developed what most of us (although not all of us) would say are probably false memories--for example, memories that people have of being abducted by aliens and taken up in spaceships and sexually experimented upon and then returned to their beds on earth. |
Application of false-memory research
I have worried about the questionable practices of harmful psychotherapy situations, which represent the minority of all psychotherapy situations. I worry for the patients. If therapists are diverting the patients away from the true cause of their problems, from getting real help, it's obviously not doing these patients any good. There is even some evidence of real harm done. I worry about the families and extended families that are accused of sexual molestation based on false memories that have been discovered. Accusations can split families apart. |
False-memory planting has also been a big problem for the mental-health field, as a result of the uncritical acceptance of every claim of abuse, no matter how unlikely. The relentless efforts to dig out these memories has trivialized and tarnished the reputation of the mental-health profession, dragging down the good therapists along with the questionable ones. |
Recommendations to avoid false-memory planting
But there is hope. The American Psychiatric Association (which I think has been more responsible than the American Psychological Association in terms of addressing this problem of false-memory planting and recognizing its difficulties) produced a two-page fact sheet containing the following recommendations. I think that they are a little bit tame, so I will reword them for you:
- Be empathetic.
- Be non-judgmental and neutral.
- When no corroborating evidence is available, help the patients to come to their own conclusions or to deal with uncertainty.
- Do not give public statements regarding the accuracy of people's uncorroborated reports of new memories (which has led to verdicts against mental-health professionals).
- Consider further research and education.
The value of these recommendations is, from my point of view, the acknowledgment
that there is a problem, and the willingness to address it. |
Lastly, uncritical acceptance of claims of abuse and of some of the therapy practices at work trivializes the experiences of the real crime victims in our society--the genuine victims of childhood trauma as opposed to those who have had false memories of trauma planted in them. The experiences of true victims are diluted, and their suffering increases. For these reasons, I have been trying to speak out about this problem as forcefully as I can. Thank you for giving me an opportunity to do that. |
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