Influence of expert testimony regarding eyewitness accuracy on jury decisions

To determine the influence of expert testimony regarding the general unreliability of eyewitnesses, a two-phase study was conducted. In the first phase, 24 community residents served as jurors on four six-person juries. A burglary case was tried in 120 District Court. El Paso, Texas. Two juries heard all the evidence including the expert testimony of a psychologist and the other two heard all of the testimony except that of the psychologist. During the second phase, 24 student jurors constituting four six-person juries viewed a videotape of the trial. Two of these juries saw the entire proceeding from the first phase including the expert testimony and the remaining two saw all but the expert testimony. All juries acquitted the defendant; however, those who heard the expert testimony significantly lowered their judgments of the accuracy and reliability of eyewitness identification as well as its overall importance to the trial. Further, those juries that heard the expert testimony spent a significantly longer time discussing eyewitness identification as well as other relevant evidence. No differences between community residents and college student juries were obtained.The authors wish to thank Judge Brunson Moore, Mr. David Jeans, Mr. Ricky Glenn Smith, Detective James Christianson, D. Steven Cooper, Rachel Hanna, Daniel Torres, and Patricia Tetreault. All of these people participated in the trial and without them this research could not have been conducted. This research was supported by Gift Funds of the Department of Psychology, University of Texas at El Paso.     

Heuristics in causal reasoning and their influence on eyewitness testimony

Abstract

In two experiments the effect of knowledge of the seriousness of an event's outcome on the estimated strength of its causes was studied. In experiment 1 participants (n=87) were shown a video of a homeless man being evicted from a police station by a police officer, during which the evictee fell. One group of participants were told that the homeless man subsequently died; the other group was told that he was uninjured. Participants who thought the homeless man had died more often blamed the policeman for the man's fall. Estimations of the force of the push were not directly related to the outcome of the event, but rather to the attribution of blame, with those who blamed the officer giving higher estimates of the force of the push. In experiment 2, before watching a revised version of the video, the participants (n=88) were assigned to one of four groups. Groups A and B were told that the homeless man had died; groups C and D were told that he had survived. In an effort to counter interference of blame attribution, groups A and C were told that the officer was to blame for the man's fall, and groups B and D that the officer was not to blame. The manipulation of guilt was not successful, but this time a significant relation between event outcome and push force was found, with those who thought the homeless man had died giving higher estimates of the force of the push than those who thought that the man had survived. As in experiment 1, those who thought the homeless man had died more often blamed the policeman and those who blamed the policeman again gave higher estimates of the force of the push. It appears then that the more tragic the outcome of a violent incident, the more blame witnesses tend to attribute to the perpetrator, and the more they tend to overestimate the amount of violence involved.     

The expanding role of expert psychological evaluations and testimony in Hague child abduction litigation

Hague Convention cases are a growing niche in forensic assessments. These cases focus on returning children, or preventing their return, after international abductions, by one of the parents, has occurred. This article focuses on the legal underpinnings of the Hague Abduction Convention, the “affirmative defenses” that may be invoked to prevent a return order, including “grave risk of harm,” “mature objection”, and the “well settled defense.” The article will also focus on the increasing roles that forensic evaluators play in these matters, the distinction between the role of forensic experts in custody proceedings and Hague cases, and the inherent limitations present in these unique kinds of evaluations.     

Influences of accent and ethnic background on perceptions of eyewitness testimony

Abstract

The purpose of the present work was to investigate the effect two eyewitness factors, accent and ethnic background, have on the perceived favorability of eyewitness testimony and case disposition in criminal trials. Six variations of testimony were created and videotaped. The videotapes varied by accent and ethnic background of the eyewitness; the testimony text was identical. Four eyewitness favorability variables, (a) credibility, (b) judgment of accuracy, (c) deceptiveness, and (d) prestige, as well as their relationship to case disposition, were measured. One hundred and seventy-four undergraduate participants viewed one of the six videotapes. Results indicate that there was a significant main effect of accent for the four eyewitness favorability variables. Accent by ethnic background interactions also yielded significant findings for the four variables as well as for the defendant's degree of guilt. Results were interpreted using the Elaboration Likelihood Model. The potential importance of these results for judicial settings is discussed.     

The effects of complainant age and expert psychological testimony in a simulated child sexual abuse trial

Mock jurors viewed a videotape of a simulated child sexual abuse trial and then deliberated to a unanimous verdict. The complainant was described as either a 13- or 17-year-old female child. Jurors voted to convict more often when the younger complainant was seen, and the younger complainant was rated as more credible than the older complainant. Female jurors voted the defendant guilty more often and rated the complainant as being more credible than male jurors. Jurors voted to convict more often and rated the defendant as less credible when expert psychological testimony was specific to the case than when they were presented with either general expert testimony or no expert testimony. Jurors who saw a psychological expert testify became less accepting of child sexual abuse misconceptions than those in the no expert control condition. The implications of these findings are discussed.Millbrook Correctional Centre     

The effect of repeated questioning on children's accuracy and consistency in eyewitness testimony

Purpose. In police interviews children may be asked the same question many times. We investigated how the number of repetitions and the interval between those repetitions affected the accuracy and consistency of children's responses. Methods. 156 children aged 4–9 years watched a staged event and were interviewed individually 1 week later. Children were asked eight open‐ended questions, which were each repeated a further four times (making a total of forty questions). Half these open‐ended questions could be answered from information in the event, and half were unanswerable (so children should have said ‘don't know’ in response to these questions). The questions were repeated in gist form. The interval between an initial question and its repetitions was varied by use of other questions and twenty non‐repeated filler questions. The intervals between repetitions were immediate repetition, repetition after a delay of three intervening questions, after a delay of six intervening questions, and after ten or more intervening questions. Results. Over a quarter of children's responses to repeated questions changed, usually resulting in a decline in accuracy, particularly after the first repetition. Subsequently, the number of repetitions and delay interval had little effect on responses to answerable questions although accuracy to unanswerable questions continued to decline. Conclusions. Question repetition had a negative affect on children's consistency and accuracy. For unanswerable questions in particular, the more often a question was repeated the more likely children were to invent a response.     

Two conjectures about the issue of expert testimony

This article responds to concerns about expert testimony in experimental psychology by conjectur that disagreements about the propriety of the testimony are camouflaged arguments about the strength of psychological knowledge. Differences between proponents and opponents of expert testimony are about the state of psychological knowledge and certainty, rather than about the proper standard for psychologists to use when deciding whether to testify. A second conjecture is stimulated by the assumption that laypersons generally overvalue eyewitness testimony and that expert psychological testimony is a required corrective. The truth of this assumption rests on the debatable assertions that eyewitness identifications, without more, are potent sole determinants of trial outcome, and that lay juries need instruction from experimental psychologists about aspects of human behavior of which the jurors are definitive producers and consumers. One need not resolve these debates in order to understand that psychologists should not rely on the legal community to set the psychologists' standards for expert testimony. And psychologists, in considering their role as courtroom experts, should guard against a self-serving critique of the acumen of lay juries.     

Personal values and the value of expert testimony

Psychologists who routinely offer expert testimony to the courts about the problems of eyewitness testimony demonstrate an unwarranted degree of faith in experimental psychology. Although progress in the field ultimately depends on laboratory research, the extrapolation of laboratory research to the real world is fraught with difficulties. Among the difficulties are the following: Laboratory studies are typically not designed with ecological validity in mind, they involve fixed effects statistical designs, they do not tell us how individuals (as opposed to mean values) behave under various experimental conditions. Presentation of such studies as relevant to the specific conditions of a court case entails a significant misrepresentation of the results of the research.     

Psychiatric expert testimony on aggressive offenders in juvenile court proceedings

The empirical study presented concerns juvenile court cases (aggressive offences) in West Berlin during which the offenders (N = 94) were subject to psychiatric expert testimony (1975-1982). The conditional factors determining forensic-psychiatric testimony are examined and the investigation shows, with the aid of discriminant analysis, that differences in the form of the expertise given are best explained by the variable 'convention-orientation'. Ratings on the quality of psychiatric letters (N = 49) were based on the semantic differential technique. Employing factor analysis, three independent aspects determining the quality of expert opinion are revealed, namely the factors 'cogency of message', role-conception', and 'recipient-orientation'.