Modern Psychological Studies Volume 1 Number 1 Article 4 1992 The interaction of source and post-event misinformation on the accuracy of eyewitness testimony Dirk Dickens Loyola Marymount University Alice Ishigame Loyola Marymount University David Subacz Loyola Marymount University Stephanie Sponsel Loyola Marymount University Matthew Strader Loyola Marymount University See next page for additional authors Follow this and additional works at: https://scholar.utc.edu/mps Part of the Psychology Commons Recommended Citation Dickens, Dirk; Ishigame, Alice; Subacz, David; Sponsel, Stephanie; Strader, Matthew; and Foy, Judith (1992) "The interaction of source and post-event misinformation on the accuracy of eyewitness testimony," Modern Psychological Studies: Vol. 1 : No. 1 , Article 4. Available at: https://scholar.utc.edu/mps/vol1/iss1/4 This articles is brought to you for free and open access by the Journals, Magazines, and Newsletters at UTC Scholar. It has been accepted for inclusion in Modern Psychological Studies by an authorized editor of UTC Scholar. For more information, please contact [email protected]. The interaction of source and post-event misinformation on the accuracy of eyewitness testimony Author Dirk Dickens, Alice Ishigame, David Subacz, Stephanie Sponsel, Matthew Strader, and Judith Foy This articles is available in Modern Psychological Studies: https://scholar.utc.edu/mps/vol1/iss1/4 Dirk Dickens, Alice Ishigame, David Subacz, Stephanie Sponsel, Matthew Strader, and Judith Foy The Interaction of Source and Zaragoza & Koshmider, 1989). Furthermore, eyewitnesses exposed Post-event Misinformation on to misleading information on some aspect the Accuracy of Eyewitness of a previously witnessed event are likely to Testimony report the misleading information with confidence (McCloskey & Zaragoza, 1985; Dirk Dickens, Alice Ishigame, Zaragoza, McCloskey & Jamis, 1987; David Subacz, Stephanie Sponsel, Tversky & Tuchin, 1989). However, a Matthew Strader, and Judith Foy significant line of research (Bekerian & Loyola Marymount University Bowers, 1983) suggests that the malleability of eyewitness memory is ABSTRACT largely due to a mismatch of encoding - retrieval cues . Bekerian & Bowers The recall of an event such as a proposed that the typical paradigm used to robbery has been shown to be affected by study eyewitness memory (slide how closely post-event information presentations, questionnaire containing corresponds to what the witness actually misleading questions, recognition* memory saw. The purpose of this study was to tests would bias subjects towards forgetting investigate how the effect of misleading the critical details since the thematic context information may be influenced by expertise in which subjects recalled did not match of the source of the post-event information. their encoding context. When order was Results revealed that subjects recalled less preserved at recall these authors found no accurately when they received misleading effect of misleading information (Tulving & information in the narrative than when the Thomson, 1973). Zaragoza and Koshmider information corresponded with what they (1989) found that exposure to misleading had viewed, whereas the accuracy of the information did not lead subjects to believe recall was unaffected by whether the that they remembered seeing the witness in the narrative was an expert or a misinformation nor did it reduce subjects' non-expert. Subjects rated the narrative ability to accurately identify the source of witnesses as having equal credibility. This the originally seen details. The results of study suggests that the memory for events this study do not support the hypothesis related to a crime-scene may be impaired by that misleading information impairs misleading post-event information, but is memory of the originally seen event and unaffected by the source of that misleading suggests that subjects may report information when the sources differ in misinformation from the narrative even if occupational expertise. they know they did not see it. Lindsay (1990) supported the INTRODUCTION hypothesis that misleading suggestions can impair recollection. This result was A significant body of literature has consistent with Loftus's original shown that misleading post-event hypothesis. Lindsay's study however was information impairs memory for the original different from the other studies in that this event (Loftus, 1979; Loftus & Loftus, study used the design based on the "logic of 1980). Many of these studies involved opposition", and the study consisted of subjects looking at a slide presentation of an informing the experimental subjects that event, reading misleading post event they were going to be deceived in the information, and answering a questionnaire questionnaire. It is quite possible that the measuring recall accuracy. The results suggestion alone might have caused the consistently indicated that misinformation subjects to be overly cautious in reading the did affect recall accuracy (Lindsay, 1990; narrative and answering the recall Loftus, Miller, & Bums, 1978: McCloskey questionnaire which in turn might have & Zaragoza, 1985; Tousignant, Hall & affected the results. Loftus, 1986; Tversky & Tuchin, 1989; Previous research studies on Zaragoza, McCloskey & Jamis, 1987; eyewitness testimony have focused on the MODERN PSYCHOLOGICAL STUDIES 14 THE INTERACTION OF SOURCE AND MISINFORMATION effects of misinformation on the accuracy of Credibility may also be recall. However, there has not been a study operationally defined in terms of that has studied the effects of correct experience. A study done by Okamoto & information on accuracy recall. All of the Sugahara (1986) defined a credible source previous studies had used misinformation as someone who watched the film 5 times for the experimental condition and for the and the non- credible source as someone control condition used "neutral" information who watched the film only 1 time. The that was neither consistent nor inconsistent study consisted of subjects viewing a film with the correct information. Correct and reading narrative about the film and information would increase recall accuracy; answering questions testing recall accuracy. for example, in realistic cases where The results of this study indicated that post- eyewitnesses are not sure of the details, event information affected recall; however, correct information might cue memory and perceived credibility did not effect recall. In enhance recall accuracy. In the present the present study we investigated the study one we investigated the effects of influence of a different operational incorrect information compared to correct definition of expertise: the influence of information on recall accuracy. occupational expertise(expert(policeman) The studies done on eyewitness versus non-expert(salesman)) on acceptance testimony have great implications in the of misinformation and/or correct areas of social psychology and law. In information. court cases involving eyewitness testimony To summarize, when subjects it is important for the witness to be able to witness an event and are .exposed to testify to accurate information. Eyewitness misinformation about the event, past testimony is commonly accepted as being research suggests that the subjects would the truth by juries; however, in light of report the misinformation with confidence recent studies on the subject of eyewitness (Lindsay, 1990; Loftus, Miller & Burns, accuracy, the results are convincing that 1978; Zaragoza & Koshmider, 1989). recall might not always be accurate. In the Whether these findings reflect a rewrite of judicial setting, it is common to see lawyers the original memory or a retrieval use "misleading suggestions" to get the interference is not yet known. We propose witness to answer in a way that provides that if subjects are more easily misled by an evidence for their case (Smith, 1989); expert source than a non-expert, then there therefore, it is important to know whether is some source monitoring error occurring or not witnesses can be persuaded to report of either encoding or retrieval. Source incorrect information. monitoring error refers to the inability of the In addition, politicians, lawyers, subject to discriminate between information and other professionals have utilized their obtained from the original event and credibility to improve acceptance of their information obtained from the post-event messages. A study by Chebat, Filiatrault narrative. Source monitoring error would and Perrien (1990) investigated the effect of suggest something other than passive credibility on message acceptance, where rewrite system. When subjects are given credibility had two component, cognitive statements by an expert as opposed to a and affective. The cognitive component was non-expert source, the research data trustworthiness and expertness, and the suggests that the subjects are more likely to affective component consisted of accept information from the expert source attractiveness and prestige. The subjects (Chebat, et. al., 1990). In the present study answered a questionnaire on credibility of we investigate two hypotheses: subjects are the source and message acceptance. The more likely to be misled by incorrect results of their study indicated that information than correct information, and credibility has an impact on message subjects will be more likely to report the acceptance where the more credible source information that comes from the expert than had the greater message acceptance