Memory Conformity: Can Eyewitnesses Influence Each Other’s Memories for an Event?
Fiona Gabbert, Amina Memon and Kevin Allan
The current study investigated memory conformity effects between individuals who witness and then discuss a criminal event, employing a novel procedure whereby each member of a dyad watches a different video of the same event. Each video contained unique items that were thus seen only by one witness. Dyads in one condition were encouraged to discuss the event before each witness (individually) performed a recall test, while in a control condition dyads were not allowed to discuss the event prior to recall. A significant proportion (71%) of witnesses who had discussed the event went on to mistakenly recall items acquired during the discussion. There were no age-related differences in susceptibility to these memory conformity effects in younger (18–30 years) as compared to older (60–80 years) participants. Possible social and cognitive mechanisms underlying the distortions of memory due to conformity are discussed.
In conclusion, it is human nature for people to discuss their shared experiences, especially if they concern something out of the ordinary such as witnessing a crime. However, as the present results clearly demonstrate, if witnesses have discussed an event with one another then the police should take great care not to give undue weight to the consistency of their independent statements when judging their accuracy.
A striking example of how the memory report of one witness may influence that of another during discussion comes from an analysis of witness evidence in the Oklahoma bombing incident in 1995. The key evidence in this case came from interviews with witnesses who worked at Elliot’s Body Shop where Timothy McVeigh rented the truck used in the bombing. McVeigh was arrested for the mass murder but there was a question as to who, if anybody, was his accomplice. Three witnesses saw McVeigh when he hired the truck, one of whom claimed he was accompanied by a second man. Initially, the other witnesses gave no description of this accomplice; however, later they too claimed to remember details of this second person. Months later, the first witness confessed that he may have been recalling another customer. So, why did all three witnesses provide a description of an accomplice when McVeigh had actually entered the shop alone? It is likely that the confident witness unintentionally influenced the others, leading them to report that they also recalled this second man (Memon and Wright, 1999; Schacter, 2001). Indeed, witnesses admitted in testimony that they had discussed their memories before being questioned (Memon and Wright, 1999).
Memory Conformity: Disentangling The Steps Toward Influence During A Discussion
Fiona Gabbert, Amina Memo, and Daniel B. Wright
When two people see the same event and discuss it, one person's memory report can influence what the other person subsequently claims to remember. We refer to this as memory conformity. In the present article, two factors underlying the memory conformity effect are investigated. First, are there any characteristics of the dialogue that predict memory conformity? Second, is memory conformity differentially affected when information is encountered that omits, adds to, or contradicts originally encoded items? Participants were tested in pairs. The two members of each pair encoded slightly different versions of complex scenes and discussed them prior to an individual free recall test. The discussions were audiotaped, transcribed, and analyzed. Our most striking finding was that the witness initiating the discussion was most likely to influence the other witness's memory report. Furthermore, witnesses were most likely to be influenced when an additional (previously unseen) item of information was encountered in the discussion.
Say It To My Face: Examining The Effects Of Socially Encountered Misinformation
Fiona Gabbert, Amina Memon, Kevin Allan and Daniel B. Wright
Objectives. Errors in eyewitness accounts can occur when a witness comes into contact with post-event ‘misinformation’. A common way to encounter misinformation is through face-to-face interaction, in particular, via conversation with other individuals who also witnessed the crime. The current research compares this kind of misinformation with the non-social post-event narrative method typically employed in laboratory studies.
Method. Young (17–33 years) and older (58–80 years) adults viewed a simulated crime event on video and were later exposed to four items of misinformation about it. The misinformation items were either introduced as part of a discussion about the event with a confederate or were embedded within a written narrative about the event that participants were asked to read. A questionnaire containing 20 items about the event was given to participants before and after the experimental manipulation.
Results. Participants were less accurate than controls on questionnaire items after encountering misinformation. More importantly, misinformation encountered socially was significantly more misleading than misinformation from a non-social source. This was true for both young and older adults.
Conclusion. Misinformation encountered socially produced more errors than misinformation from a non-social source. This finding has implications both for applied (forensic) and theoretical understanding of eyewitness memory.
Memory Conformity And Paranormal Belief
Krissy Wilson and Christopher C. French
The study found that a significant proportion of witnesses who had discussed an observed event with a co-witness reported items of information that could only have been acquired during the course of that discussion. These results replicate previous findings and demonstrate a robust memory conformity effect. It was not found that believers in the paranormal were more susceptible than non-believers to memory distortion for a non-paranormal event.