The Effects of Group Discussion on Eyewitness Accuracy

Previous research on group performance in judgmental tasks reveals that groups are rarely inferior, and often superior, to the average individual. The present study examined whether this pattern of results extends to the accuracy of eyewitness reports of a crime. It was found that group discussion led to accounts that were significantly more accurate than the average individual. A requirement to reach a unanimous decision did not alter any of the effects of group discussion. Group superiority was especially clear in terms of the completeness of the reports and in estimations of the duration of the incident. The discussion considered the implications of the present results for the current practice of prohibiting group discussion as an aid to the preparation of testimony.     

A Lay Perspective on the Accuracy of Eyewitness Testimony1

To understand more about what laypeople think they “know” about eyewitness testimony, 276 jury-eligible university students were asked to indicate what factors they believe affect the accuracy of eyewitness testimony. In contrast to the large proportion of eyewitness-memory research that concerns system variables, the lay respondents overwhelmingly generated factors related to estimator variables, while system-variable factors such as police questioning and identification procedures were rarely mentioned. Respondents also reported that their own common sense and everyday life experiences were their most important sources of information about the accuracy of eyewitness testimony. Not only do these results clarify the need for further research on the lay perspective of eyewitness testimony, but they also provide some insight into the way in which many jurors might approach cases involving eyewitness evidence.     

事件后信息影响目击证言准确性的实验研究

本研究探讨了不同案件类型、不同性别及给予不同的事件后信息对目击证言的影响,征集了男女大学生被试101名,进行了实验研究,研究结果如下:(1)以主体信息的记忆成绩为因变量,性别、案件类型和事件后信息为白变量,得出案件类型主效应显著,事件后信息的主效应显著,性别主效应以及各因素的交互作用都不显著;(2)以情境信息的记忆成绩为因变量,性别、案件类型和事件后信息为自变量,得出事件后信息主效应显著,案件类型和事件后信息之间交互作用效应显著;(3)不同性别、接受不同案件信息的被试对不同信息记忆的确信程度有所不同.     

Change Blindness and Eyewitness Testimony

The authors explored the relevance of research on change blindness to eyewitness identification and testimony under intentional and incidental memory conditions. Participants (N = 80, 40 men and 40 women) viewed a video enactment of a burglary in which the identity of the burglar changed at the halfway point of the film. Half of participants were briefed to remember the content, and the other half were not. All were tested for the recall of the content, awareness of the change, and ability to identify either or both of the burglars. Some 61% of participants did not notice the identity change. Rates of detection were significantly higher in participants in the intentional condition, who also recalled significantly more detail from the film. Awareness of change was also significantly related to content recall scores and accuracy of identification of both burglars. The results illustrate the interrelation between the eyewitness and change blindness literatures.     

Perspective Effects on Recall in a Testimony Paradigm

The two present studies examined the influence of perspective instructions given during encoding and retrieval on the recall of a visual event. Participants viewed slides or a film depicting a day in the life of a man. Before viewing the to-be-remembered event, they were instructed to adopt the perspective of an alcoholic vs. an unemployed man vs. no perspective (Experiment 1), or of an unemployed man vs. no perspective (Experiment 2). Participants in the first study were interviewed twice, with the second recall being preceded by either a change perspective instruction or without any specific instruction. In the second study, participants were interviewed using either a cognitive interview (CI) or a CI without the change perspective instruction. Results showed that adopting a perspective during encoding impaired recall performance and failed to demonstrate a significant benefit of the change perspective instruction. The theoretical and practical implications of these results are discussed.     

Double Exposure: The Effects of Repeated Identification Lineups on Eyewitness Accuracy

Eyewitnesses may be asked to identify the same suspect from a lineup on successive occasions. This study explored the effects on eyewitness decisions of repeated same‐suspect lineups, within a 2 × 2 × 2 mixed‐model factorial design. Witnesses to a video crime attempted to identify the culprit from two same‐format lineups (simultaneous or sequential) separated by a 2‐week retention interval (Lineup1, Lineup2) in which a suspect (guilty or innocent) was common to the lineups. We predicted two components of a posited repeated lineup effect: that positive identification errors made at the first lineup would be carried forward rather than corrected at the second lineup and that the number of false identifications of the innocent suspect would rise from first to second lineup. Predictions were supported, with a stronger negative impact of repeated lineups for simultaneous than sequential lineups. Additionally, witnesses who made selections of the guilty suspect and of the innocent suspect at Lineup2 were equally confident and were significantly more confident than witnesses who declined to pick. The results underscore concerns about possible negative outcomes from repeated lineups. Copyright © 2013 John Wiley & Sons, Ltd.     

The Discrediting Effect in Eyewitness Testimony1

Loftus (1974) had subjects read summaries of criminal trials that contained the testimony of either credible or discredited prosecution eyewitnesses, and found no effect of discrediting an eyewitness. Instead, almost as many subjects voted guilty with a discredited eyewitness as with a credible eyewitness; this led Loftus to the conclusion that jurors tend to overbelieve eyewitness testimony. Loftus's conclusion was subsequently challenged by others who reported a strong discrediting effect. A series of three experiments using college students was conducted to explore the characteristics of trial summaries that might account for the discrepancy in results, such as inclusion of judicial instructions concerning proof beyond a reasonable doubt, or an eyewitness's reaffirmation of his testimony following discrediting. In all cases, a strong discrediting effect was found. Apparently the discrediting effect appears regardless of wide variation in content of trial summaries. The present data do not support the overbelief claim.     

The Effects of Discussion on Eyewitness Memory1

This study investigated the effects of witness discussion on the accuracy of recall and misidentifications in eyewitness memory. Dyadic groups who discussed the crime and dyads who made joint memorial decisions about the incident were more accurate in recall than were dyads who discussed noncriminal matters, and a no-discussion group. Collaborative dyads giving joint decisions also were significantly more accurate than were the other groups in rejection of the culprit-absent lineup. The sequential lineup method proved superior to the simultaneous method, regardless of whether or not witnesses discussed the crime prior to identification. It was concluded that discussion and joint decision making by 2 eyewitnesses can improve both eyewitness recall and minimize false identifications in some circumstances.     

Judge's Instruction on Eyewitness Testimony: Evaluation and Revision1

Studies of the reliability of eyewitness identification show that such testimony may frequently be inaccurate; because of this inherent unreliability, the law has established certain safeguards to the use of eyewitness evidence. One safeguard has been the development of an instruction that a judge may use to focus jurors' attention on the eyewitness issue. The effectiveness of this instruction has never been assessed, although other studies confirm that jurors frequently misunderstand or incorrectly use instructions they get from the judge. The purpose of these studies was to evaluate comprehension of this instruction in the context of a videotaped trial and to develop a simplified instruction that would be easier for jurors to understand. Compared to jurors who heard the existing instruction, those with the revised version were more knowledgeable of the factors to consider when listening to eyewitness testimony and were less likely to convict the defendant. A sample of superior court judges in the U.S. thought the simplified instruction was more effective than the existing version at conveying the intended legal concepts to the jury, but also rated it as more strongly biased toward the defense.     

Confidence–Accuracy Calibration with General Knowledge and Eyewitness Memory Cued Recall Questions

Summary: The confidence–accuracy relationship has primarily been studied through recognition tests and correlation analysis. However, cued recall is more ecological from a forensic perspective. Moreover, there may be more informative ways of analysing the confidence–accuracy relationship than correlations. In the present study, participants viewed a video of a bank robbery and were asked cued recall questions covering general knowledge and the video itself. Confidence ratings were collected, and correlations, calibration and discrimination measures were calculated. All measures indicated a strong confidence–accuracy relationship that was better for general knowledge than eyewitness memory questions. However, there were no differences in confidence ratings for correct answers, suggesting that the differences could be limited to the evaluation of incorrect answers. We concluded that confidence may be a good marker for accuracy with cued recall, but that further research using ecological tests and more informative data analysis techniques is needed. Copyright © 2011 John Wiley & Sons, Ltd.     

The Psychology of Eyewitness Testimony: A Comparison of Experts and Prospective Jurors

To compare people's beliefs about eyewitness testimony with expert opinion, 79 college students and community adults filled out a questionnaire in which they reported whether they agreed or disagreed with 21 statements previously used in a survey of eyewitness experts (Kassin, Ellsworth, & Smith, 1989). The results indicated that there was a significant inter-item correlation of agreement rates but that subjects differed from the experts on 15 of these items. For courts seeking to determine the extent to which juries need assistance in their evaluations of eyewitness evidence, these findings offer a tentative list of topics worthy of either expert testimony or cautionary instructions from the judge.     

心理学关于目击证人证言可靠性实证研究

目击证人的证词在刑事诉讼中有着极为重要的作用,但是由于证人对案件的记忆往往会受到其自身和外界各种因素的干扰,因此,对于目击证人证词可靠性的研究引起了心理学界的关注,西方心理学界自上个世纪七十年代以来,从证人的年龄性别、心理状态、对证人的询问方式以及辨认的情景等方面进行了大量的实证研究,为司法实践提供了重要的启示。本文从以上四个方面全面总结了西方心理学界关于证人证词可靠性的实证研究,并作了分析与展望。     

Getting the Picture: Effects of Sketch Plans and Photographs on Children's,Adolescents' and Adults' Eyewitness Recall

We compared the effects of three types of visual aid on free recall across three age groups in an eyewitness paradigm. Child, adolescent and adult participants (N = 144) viewed a short film depicting a non‐violent crime and, following a brief delay, gave a free‐recall account. Participants then described the event once again, with the aid of their own sketch plan, a provided sketch plan or photograph, or with no visual aid. Interviews were transcribed verbatim and coded for the type and accuracy of information reported. Across all age groups, relative to the control condition, all three visual aids increased the amount of new information reported during the second free‐recall account and helped participants to maintain accuracy. All three visual aids therefore had a positive effect on participants' performance; in a forensic setting, however, witnesses' own sketch plans are likely to be the safest, most easily applied and most time effective.Copyright © 2015 John Wiley & Sons, Ltd.     

Eyewitness Errors in the Free Recall of Actions

Although eyewitness testimony is often unreliable, its quality is not uniformly poor. Previous research indicates that the most accurate type of testimony involves the unstructured recall of actions. The present study replicates the finding that confabulation, particularly the complete fabrication of nonexistent actions, is rare. Our results also extend earlier work by revealing that the few errors that did occur were spread evenly across subjects—with most subjects making 0 or 1 error and with no subjects making more than 3 errors. Furthermore, action memory errors form a heterogeneous set—there were few commonly recurring or predictable errors. Our attempts to increase error frequency by the use of suggestive implications and rapid action sequences were unsuccessful. Practical aspects of evaluating action memory testimony are discussed, with special reference to cases involving multiple eyewitnesses.     

Eyewitness Recall and Duration Estimates in Field Settings1

Witnesses were tested for either interrogative recall or narrative recall of a young woman to whom they had spoken for approximately 15 s, 2 min earlier. Interrogative responses were more complete and more accurate, but also more error prone than narrative responses. Men and women showed similar performance on most characteristics, but men were more confident in their responses. A negative correlation was found between age of witnesses and accuracy of recall. Women made significantly longer duration estimates of the target-witness encounters than did men. However, both men and women were relatively accurate in duration estimates when they used mental imagery rehearsal prior to giving duration judgments. The results were interpreted in terms of their forensic significance.     

The Effect of Mugshot Inspections on Eyewitness Identification Accuracy1

This study assessed the effect of commitment to an earlier mugshot identification on the ability to make a subsequent lineup identification. Shortly after viewing videotape of a staged assault some subjects rated a group of 18 photos for attractiveness, whereas other subjects attempted to identify the assailant publicly or privately in the same (target-absent) set of 18 “mugshot” photos. The remaining subjects had no intervening task. Two days later, all subjects attempted to identify the assailant from a six-person target-present photo lineup which contained their mugshot choice (if made) as well as the original assailant. Lineup identifications were significantly less accurate for subjects who had viewed the intervening mugshots (33% accuracy) than those who had only rated the intervening photos for attractiveness (64% accuracy) or had seen no intervening photos (69% accuracy). When viewing lineups, experimental subjects tended to remain committed to their earlier action of choosing or not choosing anyone from the mugshots. More witnesses who had publicly stated their mugshot choice reproduced their (incorrect) choice at the lineup (78%), than did those who made a private mugshot choice (45%), though this difference was not statistically reliable. Witnesses' confidence in their lineup decision was not significantly related to overall accuracy. Contrary to predictions from self-perception theory, confidence in one's decision decreased significantly as further identifications were attempted.