Trivial persuasion in the courtroom: the power of (a few) minor details

Investigated the influence of trivial testimonial detail on judgments of 424 undergraduates who served as mock jurors. Ss read a summary of a court case involving robbery and murder. In Experiment 1, detailed testimony influenced judgments of guilt, even when the detail was unrelated to the culprit. In Experiment 2, detailed testimony was especially powerful when an opposing witness testified that she could not remember the trivial details. Subsequent analyses suggest that the impact of detailed testimony on guilt judgments is mediated by inferences about the eyewitnesses. When eyewitnesses provided more detail, they were generally judged to be more credible, to have a better memory for the culprit's face and for details, and to have paid more attention to the culprit.     

The Influence of Eyewitness Nonidentifications on Mock-Jurors' Judgments of a Court Case1

Two experiments examined the effect of an eyewitness nonidentificution on mock-jurors' verdicts in robbery cases, as well as the effects of number of identifying eyewitnesses and status of the identifying witness (victim or bystander). Subjects read court case summaries that included variable eyewitness evidence and constant alibi, circumstantial, and character evidence. In Experiment 1, frequency of guilty verdicts was significantly less when an eyewitness testified in court that the defendant was not the perpetrator, even when this nonidentification opposed two positive identifications. In Experiment 2, a low guilty rate was again associated with the presence of a nonidentifier, but only when the nonidentifier actually testified in court and stipulated that the defendant is “not the man.” On the average, 70% of the jurors delivered guilty verdicts when both the victim and bystander gave identifying testimony, whereas 12.5% delivered guilty verdicts when the bystander gave opposing nonidentifying testimony. Guilty rates were unaffected by the identifying eyewitness' status and (in Experiment 2, but not Experiment 1) were higher when there were two (vs. one) identifying eyewitnesses.     

Preventing the Application of Stereotypic Biases in the Courtroom: The Role of Detailed Testimony1

To determine whether detailed testimony has equivalent effects on judgments of stereotyped and nonstereotyped defendants, subjects read a synopsis of a criminal court case in which the defendant either was a stereotyped offender or was not. Additionally, the degree of detail in the prosecution testimony and defense testimony was varied. Results indicated that defendant stereotypicality had a greater impact under conditions in which witnesses provided equal amounts of detail in their testimony. When witnesses differed in the degree of detail in their testimony, the stereotypicality of the defendant was disregarded and judgments favored the witness who provided greater detail. These findings suggest that stereotype application is not inevitable; rather, stereotypes may bias jurors' decision-making processes when the quality and quantity of the evidence does not easily lead to a confident judgment.     

Testifying on Eyewitness Reliability: Expert Advice Is Not Always Persuasive1

This study investigates the impact of different types of expert testimony regarding the unreliability of eyewitness identification. In two hypothetical court cases involving eyewitnesses, expert testimony was presented that was either sample-based (presenting the results of a research program on eyewitness identification) or person-based (presenting information about the particular eyewitness under consideration); the expert either offered causal explanations for his unreliability claim or failed to do so. Two additional control groups (with and without eye-witness identification) were not presented with any expert testimony. The results indicate that subjects who had been confronted with an expert statement made more lenient judgments about the offender but did not discount the eyewitness identification completely. Sample-based information had a moderate impact on the subjects' judgments, regardless of whether or not causal explanations were given. Person-based testimony was the most influential type of expert advice when a causal explanation was provided but the least influential one when no reasons were given. The practical (international differences in admissibility of expert testimony) and theoretical implications (processing of base-rate information) of these findings are discussed.     

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.     

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。     

Repetition, not number of sources, increases both susceptibility to misinformation and confidence in the accuracy of eyewitnesses

Are claims more credible when made by multiple sources, or is it the repetition of claims that matters? Some research suggests that claims have more credibility when independent sources make them. Yet, other research suggests that simply repeating information makes it more accessible and encourages reliance on automatic processes—factors known to change people's judgments. In Experiment 1, people took part in a “misinformation” study: people first watched a video of a crime and later read eyewitness reports attributed to one or three different eyewitnesses who made misleading claims in either one report or repeated the same misleading claims across all three reports. In Experiment 2, people who had not seen any videos read those same reports and indicated how confident they were that each claim happened in the original event. People were more misled by—and more confident about—claims that were repeated, regardless of how many eyewitnesses made them. We hypothesize that people interpreted the familiarity of repeated claims as markers of accuracy. These findings fit with research showing that repeating information makes it seem more true, and highlight the power of a single repeated voice.     

Improving the Credibility of Child Sexual Assault Victims in Court: The Impact of a Sexual Assault Nurse Examiner

The present study investigated the influence of a sexual assault nurse examiner's (SANE's) testimony on mock juror perceptions of a child or adolescent victim of child sexual assault. Community members (N = 252, 156 females) read a fictional criminal trial summary of a child sexual assault case in which the victim was 6 or 15 years old and the prosecution presented medical testimony from a SANE or a traditional registered nurse (RN), or did not present medical testimony. Mock jurors were more likely to render guilty verdicts when a SANE testified compared with the other two testimony conditions. In addition, pro-victim judgments (e.g., sympathy toward the victim) and negative defendant judgments (e.g., anger toward the defendant) mediated this relation. Finally, cognitive network representations of the case demonstrated that the RN and no-medical-testimony groups were similar and the SANE group was distinct from the other two conditions. We discuss these results in terms of the implications of SANE testimony in child sexual assault court cases. Copyright © 2015 John Wiley & Sons, Ltd.     

Effects of racial stereotypes on eyewitness performance: Implications of the real and the rumoured Allport and Postman studies

The Allport and Postman (1945, 1947) study of rumour has been widely cited in support of the claim that expectations based upon racial stereotypes can cause eyewitnesses to make dramatic errors in perceiving or remembering an event. However, this claim is founded on inaccurate accounts of the study that have appeared throughout the eyewitness testimony literature. In this article we explore the implications of the actual Allport and Postman study, and the study as erroneously described, for questions about eyewitness performance.     

An archival study of eyewitness memory of the Titanic's final plunge

A handful of real-life studies demonstrate that most eyewitnesses accurately recall central details (i.e., the gist of what happened) from traumatic events. The authors evaluated the accuracy of archival eyewitness testimony from survivors of the Titanic disaster who witnessed the ship's final plunge. The results indicate that most eyewitness testimony (15 eyewitnesses of 20) is consistent with forensic evidence that demonstrates that the Titanic was breaking apart while it was still on the ocean's surface. Despite the methodological limitations of archival research, the authors provide evidence from a single-occurrence traumatic event (with a large-scale loss of life) that the majority of eyewitnesses accurately recall central details.     

Expert testimony and jury decision making: An empirical analysis

This experiment examines the influence of expert psychological testimony on juror decision making in eyewitness identification cases. Experienced jurors and undergraduate mock jurors viewed versions of a videotaped trial, rated the credibility of the eyewitness and the strength of the prosecution's and defense's cases, and rendered verdicts. In the absence of expert testimony jurors were insensitive to eyewitness evidence. Expert testimony improved juror sensitivity to eyewitness evidence without making them more skeptical about the accuracy of the eyewitness identification. Few differences emerged between the experienced jurors and undergraduate mock jurors.     

An Archival Study of Eyewitness Memory of the Titanic's Final Plunge

A handful of real-life studies demonstrate that most eyewitnesses accurately recall central details (i.e., the gist of what happened) from traumatic events. The authors evaluated the accuracy of archival eyewitness testimony from survivors of the Titanic disaster who witnessed the ship's final plunge. The results indicate that most eyewitness testimony (15 eyewitnesses of 20) is consistent with forensic evidence that demonstrates that the Titanic was breaking apart while it was still on the ocean's surface. Despite the methodological limitations of archival research, the authors provide evidence from a single-occurrence traumatic event (with a large-scale loss of life) that the majority of eyewitnesses accurately recall central details.     

Effects of the Inclusion and Refutation of Peripheral Details on Eyewitness Credibility

The present study examines the effects of including trivial details in eyewitness testimony on witness credibility, as well as the effects of discrediting presented details. Participants ( N = 155) read 2 brief, contradictory depositions from fictional witnesses about a fictional car accident. One of the depositions included a short set of details unrelated to the accident itself. After participants rated the credibility of the witnesses, the trivial details were refuted and the participants rated the credibility of the witnesses again. Contrary to previous research (Bell & Loftus, 1989), the inclusion of trivial details had no effect on witness credibility. However, significant effects on witness credibility were obtained when the details were refuted. As expected, the credibility of the witness presenting the trivial details significantly decreased after detail refutation. More interestingly, refutation appeared to increase the credibility of the other witness.     

Truth and Consequences: The Effect of Responsibility on Eyewitness Behavior

Previous research has revealed that eyewitness identification errors are so common as to render such testimony of questionable value as courtroom evidence. However, all of this research was conducted in settings where the eyewitnesses were not responsible for the consequences of their responses—that is, they were aware they were in an experiment. The present research compared eyewitness behavior in an explicitly experimental setting with behavior in a setting that the subjects perceived to be real and in which loss of time, potential embarrassment and discomfort, a student's reputation, and the validity of a scholarship competition were at stake. Surprisingly, two studies both found that subjects were just as willing to offer information, just as willing to make a positive identification, and just as inaccurate in the real as in the experimental setting. These results indicate that previous research has accurately portrayed eyewitness error rates in actual investigations. Implications of the present research for the use of eyewitness testimony are discussed.     

Reaction of mock jurors to testimony of a court appointed expert

A study was conducted to assess the impact of court appointed experts on the judgments of mock jurors. A civil proceeding was adopted for the experiment. Mock jurors heard testimony about a plaintiff's injury in an automobile accident. In some conditions, medical testimony for the plaintiff and defendant was provided by experts hired by each side. In other conditions, a medical expert appointed by the court testified in addition to the two adversarial experts. In one of these conditions, the court expert sided with the plaintiff; in another, the expert sided with the defendant. The plaintiff in the case was always an individual. The defendant was sometimes a corporation and sometimes an individual. The results showed that mock jurors sided with the court appointed expert in every condition except when the expert favored a corporate defendant. The results were discussed in terms of heuristic processing of persuasive information.     

Sensitizing Potential Jurors to Variations in Eyewitness Evidence Quality Using Counterfactual Thinking

Jurors often have difficulty evaluating eyewitness testimony. Counterfactual thinking is a type of mental simulation that informs causal inference. Encouraging jurors to think counterfactually about eyewitness factors may sensitize them to these factors' causal influence on eyewitness identification and testimony accuracy, improving their overall judgments (such as verdicts). One hundred twenty‐one undergraduate participants were randomly assigned to read a scenario containing either high‐quality or low‐quality eyewitness evidence and to evaluate eyewitness factors adopting either their default or a counterfactual mindset via a question‐order manipulation. Logistic regressions and analyses of variance revealed that a counterfactual mindset lowered perceptions of eyewitness accuracy and guilty verdicts (compared with the default mindset) when the evidence was poor; a counterfactual mindset, however, did not increase perceptions of accuracy and guilty verdicts when evidence was strong. We discuss possible mechanisms underlying these effects and identify several potential avenues for future research.Copyright © 2016 John Wiley & Sons, Ltd.