How to Think Critically: Memory & Confabulation

The reliability of eyewitness accounts is one of the bedrock beliefs of our society. In ancient cultures – and in some modern cultures that still follow ancient laws – some crimes could only be proven by eyewitness testimonies. One of the most infamous examples was Pakistan’s Hudood Ordinances, which mandated that allegations of rape could only be proven by four eyewitness accounts; otherwise, the woman was to be punished for making false accusations. Even in our supposedly more enlightened society, eyewitness testimonies still carry great weight in criminal trials – this despite ample evidence that they are often mistaken, resulting in many wrongful imprisonments.

The willingness of juries, and people in general, to believe eyewitness testimony stems from a faulty view of the nature of memory. Human memory is not like a tape recorder or a video camera, creating a record of events and then playing them back exactly as they were first observed. Rather, human memory is basically reconstructive: in most cases, we remember only the basic outlines of an event, and if we’re called upon to retell what happened, the mind fills in the gaps with whatever details are at hand. This means that details that are fed to a person may subconsciously be incorporated into their memories and presented by that person as an accurate account of history.

One of the classic examples of this is an experiment done by the memory researcher Elizabeth Loftus. In it, Loftus interviewed the relatives of her research subjects to get three true stories of childhood events that had happened to each of them. To those three stories, she added a fourth one, which she confirmed with relatives had not actually happened: a story about the subject being lost in a mall at the age of five, crying and being comforted by an elderly woman, and finally being reunited with their parents. The subjects were each presented with these stories and asked to write down as much additional detail as they could remember about each of them. About 25% of Loftus’ subjects “remembered” the fictitious account and described it as a true story that had happened to them in childhood (source). Similar studies along this line have found that, in follow-up interviews conducted later, more and more subjects remembered the false stories over time, with some even embellishing them with details of their own that weren’t part of the original presentation.

Another study by Loftus found that subjects’ memories of events can be altered by questions that presuppose a particular set of facts. In this experiment, 150 students saw a short film of an accident involving a white sports car and then answered questions about it. One set of students was asked, “How fast was the white sports car going when it passed the barn?” (There was no barn in the film.) The other set was simply asked, “How fast was the white sports car going?” One week later, both sets of students were brought in for a follow-up interview, and both were asked, “Did you see a barn in the film?” Students who had previously been asked about the non-existent barn were far more likely (17% vs. 2%) to incorrectly believe that it had been present the first time.

Even memories of highly emotionally charged events – so-called “flashbulb” memories – are just as likely to suffer this distortion. Just like any other memory, subjects tend to forget true details or add embellishments over time. But what’s worrying is that, despite this error creep, people tend to put more confidence in their flashbulb memories and are more likely to believe they’re accurate, even when the record shows otherwise.

And finally, the most sensational example of how memory can fail us: In 1975, the Australian psychologist Donald Thomson was arrested and charged with rape, and was informed by police that the victim had positively identified him as her attacker. This was a great surprise to Thomson, because he had a seemingly invulnerable alibi: he was on live TV at the time, being interviewed in the presence of a studio audience, cameramen, and an assistant police commissioner. As it turned out, the woman who was raped had been watching that very program just before the attack. She had mixed up Thomson’s face on the TV screen with the face of her attacker. Ironically, Thomson had been on TV to discuss the unreliability of eyewitness testimony. (source; see also)

The human tendency to confabulate details and misattribute sources means that memory, especially in the long term, cannot be counted on as a reliable source of information. This doesn’t mean that eyewitness accounts should be excluded from trials and other decision-making altogether, but they should be considered with greater attention to their fallibility. When we question witnesses about the details of an event, we must avoid leading questions that could implant details into their minds. When victims of crime are asked to pick their assailants out of a lineup, those lineups should be double-blind. And testimonies should be given greater weight when two or more witnesses independently agree on the same details or when they are supported by other evidence.

Other posts in this series:

About Adam Lee

Adam Lee is an atheist writer and speaker living in New York City. His new novel, Broken Ring, is available in paperback and e-book. Read his full bio, or follow him on Twitter.

  • Leum

    Good post, I have two comments:

    How do you propose to have police lineups be double-blind?

    I recall reading somewhere (or hearing on NPR) that not only is memory fallible, but that since each time we remember we reconstruct, the more often we recall something, the more likely it is to be distorted. So things you remember just once are actually more accurate than those moments you relive constantly (which, reassuringly, means some of my most embarrassing moments may not have been half as bad as I now consider them).

  • John A. Michon

    The problem raised in this post is of great potential relevance when it comes to eyewitness testimonies in religious matters, especially with respect to reports of miracles and apparitions (think for instance of the Fatima lore) and confessions as they may occur during the services of fundamentalist, e.g. Pentecostal sects. This posting, unfortunately — although it correctly points out some memory-related aspects of critical thinking — appears to throw very little (day)light on that particular potential relevance. I wish to emphasize here that it could turn into a proper field of empirical analysis of religion-inspired claims. It might, for instance, clarify the claims of the French nun Marie-Simon-Pierre (45), who was mysteriously cured of Parkinson’s disease, through the spiritual intervention of pope John Paul II who, himself, was suffering from the same disease. This is supposedly one of the miracles required for this pontiff on his way to sainthood.
    There is little hope, unfortunately, that this empirical approach will affect the ways of the RC church (or any other religious denomination for that matter). It could serve, however, in the systematic atheistic approach to ongoing the nature-religion debate. The Austrian philosopher Hubert Schleichert has proposed a way of “Subversive Thinking”" as a means of “debating with fundamentalists without going out your mind” (see ref. 1 below). In summary there is, in Schleichert’s opinion, no way one can communicate sensibly with ‘defenders of the faith’. All apologetic tricks are known and have been polished over the past 20 centuries. Which leaves only ‘subversive’ ways of debating. One is ridicule, the other is ‘taking the opponent utterly serious’ by carrying the opponent’s position to it logical extreme and thereby reducing it ‘ad absurdum’.
    The approach advocated in the present post, should be useful for the second strategy.
    In this context I wish to emphasize here that the the various perspectives on legal evidence have been studied in deep and fundamental ways by several of my colleagues in the Netherlands, to wit, Willem A Wagenaar, Hans F M Crombag, Peter J van Koppen, Harald Merckelbach, all of whom can easily be found at Google Scholar or ISI. Especially I refer to a recent book by Willem Albert Wagenaar and Hans Crombag that throws the clear light of contemporary cognitive psychology on legal evidence (see ref. 2 below). It covers not just things related to perpetrators and witnesses, but also on the — frequently irrational or ignorant — considerations and opinions of the courts. In the Netherlands (and internationally too) the work of these prominent experimental psychologists initially met with considerable resistance from the lagal professionals. Now, some 20 years later, much of what they brought up theoretically and in deeply researched case studies is having a considerable impact on the way criminal cases are treated in this country. One result is the establishment of a national council that may decide to offer serious criminal cases to the (Supreme) Court for reconsideration on the basis of new facts relating tot errors of investigation or judgment, on the basis of behavioral, biological, or physical evidence. Another issue that has been central to the work of Wagenaar and Van Koppen is indeed, the proper way of carrying out line-up confrontations, something that continues to be performed in the most miserable fashions one can think of.
    As said before, although the posting and as a consequence my comment seem to have very little to do with atheism. There is a deep connection though and I consider it a pottentially fruitful approach to finding an answer to the question what ultimately drives the stubbornness of the apologetic faithful. Considering what drives the legal professional may contribute hugely to this end.

    1. Hubert Schleichert (2008). “Wie man mit Fundamentaslisten diskutiert, ohne den Verstand zu verlieren: Anleitung zum subversiven Denken” (8th Ed., 1st Ed. 2001). München: Beck. [Unfortunately I am not aware of an english translation of this very illuminating and practical analysis of apolegitc rethoric].

    2. Willem Albert Wagenaar & Hans Crombag (2008). “The popular policeman and other cases: Psychological perspectives on legal evidence. Amsterdam: Amsterdam University Press.

  • Shawn Smith

    I wonder if you saw the 60 Minutes story about this very topic a couple weeks ago. It was with respect to a woman who sent a man to prison for more than 15 years for raping her, even though he was not the man who did it. She told 60 minutes that while the rape was going on, she was doing her best to remember any details of his face so that she could put her attacker away when he was caught. It was only through the Innocence Project that DNA evidence was examined and it proved that the man convicted of the crime did not do it. He ended up forgiving her and they now go around talking to various groups about how eyewitness testimony, even when the eyewitness seems certain, can be horribly wrong.

  • John Nernoff

    The theory that memory can become unreliable with time, and re-remembering or rewriting the memory, can be taken too far. I KNOW irrefutably that I went to a certain high school, a certain college and a certain medical school no matter how far removed in time or how many times I reconstruct those facts. Of course all the little details of those experiences mat be more or less murky. This is the area of research that needs to be pursued.

    Parenthetically, I remember well, in one of those later classrooms, when a “robbery” was staged with blank gunfirings going off and distinctive clothing being worn by the assailant. I will not list all the particulars of this event, but I will say that the class did poorly in remembering all the details despite the fact they were direct eyewitnesses.

    Now shall we discuss, say, the “eyewitnesses” to Jesus’ crucifixion and resurrection not vouchsafed to writing until some many decades after, and not even found in copied form until the passage of centuries?

  • Andrew A,

    I KNOW irrefutably that I went to a certain high school, a certain college and a certain medical school no matter how far removed in time or how many times I reconstruct those facts.

    The key difference between knowing what school you went to, and remembering an event, is that you didn’t just go to any of those schools just once. You went to each of them several hundred times at least. If you were to directly experience an event hundreds of times, the memory would likely last a lifetime, and remain accurate in that time.

  • valhar2000

    John, of course you will remember certain things very well, from where you went to high school to where you left your keys this morning; human memory cannot be completely reliable, but it does have to be good enough, or only tend to fail in certain conditions, or else it would not have evolved.

  • Quidam

    There is an interesting case currently under investigation.

    Several RCMP officers gave evidence about how Robert Dziekanski was subdued with a Taser and subsequently died at Vancouver Airport. Their evidence was reasonable and consistent with each other. Except that it was all contradicted by an amateur video that the officers were not aware of until after they had given their depositions.

    The video contradicts all four officers’ earlier statements and clearly shows Dziekanski did not need to be Tasered five times to be brought under control.He was being Tasered even while already on the floor, moaning in pain. He was no threat to anyone, never mind to the four healthy RCMP officers who carried guns and wore body armour.

    Without the video their eye-witness account would have prevailed.

  • The Ridger

    The RMCP account is of course a different problem. Eyewitnesses can lie, but that’s not a memory problem.

    Who was it said that “Eyewitnesses may lie or be mistaken, but circumstantial evidence does neither”? Of course, it can be misinterpreted. Nothing’s perfect.

    But Ebon’s right in that we tend to place a lot of credence in our memories. Anecdote: I remembered for decades that the crow in Disney’s animated Sleeping Beauty flew through the puffs of pink and blue and himself turned colors. Imagine my amazement when I finally saw the thing on tape and that scene was not in it.

  • Aly

    Interestingly, just yesterday I saw a Scientific American Frontiers show (with Alan Alda–I love that guy!) on PBS that mentioned, among other things, the fallibility of memory. Alda was taken to watch two people having a picnic, and was later shown pictures of things that may or may not have happened at the picnic. Afterward, he was asked whether things (such as the girl filing her nails) actually occurred. He was surprised to find how often he was wrong.

  • Quidam

    I rather suspect that the RCMP officers would pass a lie detector test. I think they have persuaded themselves of a false version of events. When presented with the evidence of the film they say things like “I know that’s what the video seems to show but that’s not what happened”. When you replay the event in your mind it gets translated into a more flattering memory and in this case the video is a cognitive dissonance.

  • Eric

    As a juror I’d give more weight to circumstantial evidence than to eyewitness accounts. I was a jury foreman in a local celebrity assault/theft case. Turned out witness testimony made it seem plausible that the defendant hit and kicked the complaining witness mostly in self defense, so we all agreed to acquit on the assault.

    The other jurors were very quick to convict on a lesser theft charge than the prosecution wanted, but I balked at this. I argued that the jury instructions defining theft gave us six necessary conditions for an action to count as theft, and that if we had reasonable doubts about any of these conditions, we should aquit. Other jurors balked, but one juror who was a lawyer propped me up. I actually wanted to convict on that lesser theft charge myself, but I didn’t want to convict unless each of the other jurors was able to overcome my counter arguments.

    Two things I learned from this trial:

    1. If you’re the victim of a crime, file a report as soon as possible. Get pictures, take badge numbers. A jury will not believe you if you dawdle.

    2. If you think you will be accused of a crime; DO NOT COOPERATE WITH AUTHORITIES. SAY NOTHING. DO NOT CONSENT TO BEING TAPED. GET REPRESENTATION AND SAY NOTHING. DO NOT COUNT ON YOUR SMARTS OR KNOWLEDGE OF THE LAW TO SAVE YOU. Defendant in my case was a judge talked on tape with two detectives and screwed herself.

  • Ubi Dubium

    Anecdote: I remembered for decades that the crow in Disney’s animated Sleeping Beauty flew through the puffs of pink and blue and himself turned colors. Imagine my amazement when I finally saw the thing on tape and that scene was not in it.

    I think I know where that memory came from. I remember having a Disney storybook in my childhood that was illustrated with scenes and concept art from Sleeping Beauty, and it had the crow being turned pink and blue. When trying to reach back so many years for memories of seeing the movie, it’s really easy to get memories of that companion book mixed in with it. I think this is a good example of Ebon’s original premise.

  • Shu Fen

    hi ^^ first time dropping by :D

    loved your articles!

    i’m an agnostic/atheist too :]

  • Kevin Malone

    Mr. Lee -

    Your second paragraph reminds me of the following quotation:

    “Memory never recaptures reality. Memory reconstructs. All reconstructions change the original, becoming external frames of reference that inevitably fall short.”

    - Mentat Handbook, in Heretics of Dune by Frank Herbert

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