You May Question the Witness—And You Probably Should
The importance of eyewitness testimony doesn't necessarily mean it's accurate.
Posted May 08, 2020
The testimony of a credible, confident, and attractive eyewitness is among the most compelling factors in any court. This may be true whether the witness knows anything or not.
Credibility makes at least some sense. One witness has a lifelong reputation for integrity. Another witness tells you, as an inpatient told me many years ago, that he was the God of Sex, and that when he left the hospital he planned to open a two-thousand-acre pornography studio.
We have a pretty good idea which witness we’re going to believe.
Confidence? It’s complicated. In some experimental contexts, we find that confidence does not relate to witness accuracy. In other contexts it does, and in others it all just depends. These are complex issues that are just beginning to be sorted out in the laboratory
But attractiveness? There are of course attractive people who are intelligent, sincere, and honest. There are others who aren't too bright and who lie a lot. And there are other honest people, including the present writer, who could not win a beauty pageant if all the other contestants were mountain gorillas.
About all we can say about the attractiveness factor is this: if you are ever implicated in a major crime, make damned certain that your accusers are all ugly people.
Yet these three factors together tell us something about eyewitness cognition: specifically, that there’s more going on in the eyewitness than a simple recounting of facts. Eyewitness cognition is a very human activity, involving a vast panoply of human foibles.
Which probably accounts for the fact that eyewitness memory is pretty bad; and everybody knows it.
Obviously you can’t discount eyewitness accounts. They’re often the only evidence you have, and witnesses are frequently correct.
On the other hand, they’re also frequently wrong. In experiments in my lab, we’ve found lineup eyewitness accuracy rates as low as 10 percent in some cases. These rates were substantially lower than those found in some other studies and contexts; but these results happened, and if they happened in your own trial, on serious charges, you might take a pretty dim view of eyewitness evidence as a whole. (Research for this post is summarized in Sharps, 2017).
But what can psychology, especially cognitive psychology, contribute to the eyewitness debate? Why is eyewitness memory frequently so awful?
Here we must introduce the ground-breaking research of Sir Frederic Bartlett.
In 1932, Bartlett published his book Remembering, in which he reported the results of experiments that are not exactly models of modern methodological precision, but which still have a lot to teach us.
Bartlett showed research volunteers an abstract drawing that resembled an evil, football-shaped face with dental problems. The title of the drawing was Portrait d’Homme, Portrait of Man. Bartlett asked volunteers to draw and re-draw the picture.
In at least one series, the drawings became increasingly and progressively more like a human face.
If you know that the picture is supposed to be a man, your mind may reconfigure the visual memory until the demented dental football actually turns into a man, at least for you. (Note, however, that Carbon and Albrecht failed to replicate this specific result in 2012—like most things in the eyewitness realm, this effect is more complicated than we’d like.)
Another of Bartlett’s experiments involved a Native American story which included supernatural elements. When Bartlett had his British volunteers read this story and render it back repeatedly, the repeated renditions became shorter and more focused on the core of the action. But many of the elements pertinent to Native American beliefs were specifically reconfigured, changed entirely, to fit the beliefs of the British readers. Elements of this work have been successfully repeated in modern times, including in my own laboratory.
In short, Bartlett demonstrated, almost ninety years ago, the shocking truth about memory. Our memories are not veridical representations of the past, with a few forgotten bits dropped out. Instead, memories are reconfigured in our minds, in three directions.
One direction is brevity. Our memories become shorter as details are lost.
Another is the direction of gist. As details are lost, we tend to focus more on the core of what we believe we recall.
But the most frightening direction—found visually in the Portrait d’Homme (at least once), and verbally (with repeated results) in the Native American story—is the direction of personal belief. Bartlett showed that we frequently remember not what actually happened, but what our systems of beliefs direct us to remember.
Does this apply to the eyewitness realm? In my lab, we found that in eyewitness memories of a crime scene, the second most common witness error was the error of the imagination. After errors of physique and clothing of the perpetrator (almost two per witness), the average witness made 1 ¼ errors of the imagination.
In other words, witnesses just made stuff up. And they didn’t know they were doing it.
Bartlett's reconfiguration makes a lot of sense out of what we see in the eyewitness realm. Our beliefs reconfigure our memories, especially given that those memories have already been reduced in the directions of gist and brevity. Memories are not veridical representations of the past. They are representations which may have changed fundamentally in our own minds, in the genuinely human dynamics of the eyewitness process.
One cannot, of course, legitimately make a blanket condemnation of eyewitness testimony. As a number of experts in the field have pointed out, eyewitness memory is frequently accurate. And it’s often all we have.
But it’s also frequently wrong.
I hope to consider these issues in greater detail in future posts in The Forensic View. But for the moment, if you are ever wrongly charged with a crime, please remember this:
Make certain your accusers are really ugly people.
Bartlett, F.C. (1932). Remembering: A Study in Experimental and Social Psychology. Cambridge: Cambridge University Press.
Carbon, C.C., & Albrecht, A. (2012). Bartlett’s schema theory: The unreplicated “portrait d’homme” series from 1932. Quarterly Journal of Experimental Psychology, 65, 2258-2270.
Sharps, M.J. (2017). Processing Under Pressure: Stress, Memory, and Decision-Making in Law Enforcement (2nd ed.). Flushing, NY: Looseleaf Law Publications.