Collaborative Recall Reduces the Effect of a Misleading Post Event Narrative

Abstract

An extensive body of research on the fallibility of eyewitness evidence and the exoneration of those wrongly convicted through DNA analysis ultimately led attorney general Janet Reno to call for national standards for interacting with witnesses (Wells et al., 2000). Yet there is much to learn about eyewitness memory and how it can become distorted. Post event information in the form of leading questions, exposure to narrative accounts of the event and conversations with fellow witnesses can lead to significant and practically important distortions. In this experiment we further explored the effects of collaborative recall, which may occur when two witnesses are casually questioned by another individual who arrives late on the scene, such as a rescue worker, reporter, or just a curious onlooker. Leading questions (e.g. Loftus, 1975; Loftus & Palmer, 1974) and narrative accounts (e.g. Loftus, Burns & Miller, 1978) can change episodic memories and thereby affect the responses witnesses give immediately and during subsequent sessions. These effects have been replicated numerous times and many factors can contribute to them. Gudjonsson has explored suggestibility differences based on numerous individual differences and the techniques of interviewers. For example, suggestibility is negatively correlated with intelligence and memory capacity, and positively correlated with field dependence (Singh & Gudjonsson, 1992). Witnesses suffering from alcohol withdrawal (Gudjonsson, Hannesdottir, Petursson & Bjornsson, 2002) or sleep deprivation (Blagrove, 1996) are more likely to accept suggestions. Interviewers who are firm rather than friendly are more likely to elicit the effect in witnesses (Baxter, Boon & Marley, 2006). Furthermore, repeated questioning about the event can lead to greater misinformation effects (Roediger, Jacoby, & McDermott, 1996). Though younger children are more susceptible to misinformation than older children (Ceci & Bruck, 1993) and older adults show stronger effects than younger adults (Karpel, Hoyer, & Toglia, 1993), people of all ages are affected by post-event misinformation (Loftus, 2005). Co-witnesses of a crime or traffic accident may also be sources of misinformation when they spontaneously discuss what they have seen. Gabbert, Memon, Allan, and Wright (2004) found that misinformation effects are stronger with a face to face co-witness discussion than with a post-event narrative. Likewise, Paterson and Kemp (2006) found misleading post event information presented through a co-witness discussion produced misinformation errors more consistently than did leading questions, a newspaper report on the witnessed event, or a video showing a discussion between two other co-witnesses. In a procedure typical of those used in the co-witness literature, Gabbert, Memon, and Allan (2003) had pairs of participants view videos of the same incident, but from different perspectives. One witness was able to see the girl in the video steal a small amount of money, but the action was not visible from the other witness's perspective. Participants were asked to discuss the witnessed event before answering questions independently. Over a third of the participants who had discussed the event with another witness included in their statements information that had been learned through the discussion. Furthermore, 60% of these participants indicated that the girl was guilty even though they had not actually seen her take the money. In a similar study, 60% of children reported a detail that could not have been observed in the version of the video that they viewed (Candel, Memon, & Al-Harazi, 2007). Social factors of the co-witness interaction can affect misinformation effects. Information from post event discussions was more likely to be incorporated into reports of the event if the co-witness was a friend or romantic partner (Hope, Ost, Gabbert, Healey, & Lenton, 2008) and misinformation effects can be greater when misinformation is presented in one-on-one discussion than in a group discussion (Dalton & Daneman, 2006). …