Expert Testimony Pertaining to Battered Woman Syndrome: Its Impact on Jurors' Decisions

Participants (N = 200) were presented with a criminal homicide trial involving a battered woman who had killed her abuser. Within the trial, both the response history (passive, active) and presence of expert testimony pertaining to battered woman syndrome (present, absent) were systematically varied. As well, half of the participants in each of these conditions were provided with a nullification instruction informing them that they were free to disregard the law and acquit should a strict application of the law result in an unjust verdict. Results indicated that, compared to the passive response condition, the mock jurors were no less receptive to the expert testimony in the active response condition. The impact of the testimony on participants' verdicts, however, was moderated by the nullification instruction. That is, although the presence of the testimony did result in greater verdict leniency, this only occurred when the mock jurors had been released from a strict application of the law. The implications of these findings are discussed.     

Detecting Deception in Children's Testimony: Factfinders' Abilities to Reach the Truth in Open Court and Closed-Circuit Trials

This study examined the influence of closed-circuit television (CCTV) on jurors' abilities to detect deception in children's testimony. Children ages 7–9 individually played games and made a video movie with a male confederate. In the guilty condition, stickers were placed on exposed body parts (i.e., the child's arm, toes, and bellybutton). In the not-guilty and deception conditions, stickers were placed on the child's clothing rather than on bare skin. Approximately 3 weeks later, mock jurors recruited from the community viewed child participants testify either in a traditional courtroom setting or via one-way CCTV. The mock jurors responded to questions about the child witness and the defendant as well as deliberated to reach a verdict. Children in the deception condition were asked to testify as if the stickers had been placed on exposed body parts rather than on their clothing. Predeliberation, jurors were less likely to convict when a child testified in the deception condition as opposed to the guilty condition. These differences disappeared following deliberation. There was no support for the notion that jurors reach the truth better when children testify in open court versus via CCTV. Implications for jurors' abilities to reach the truth are discussed.     

Effects of Past Abuse Experiences on Children's Eyewitness Memory

Relations between child maltreatment and children's eyewitness memory were examined. A matched sample of abused and nonabused 3- to 10-year-old children (n = 70) participated in a play session with an unfamiliar adult and were interviewed about the interaction 2 weeks later. Consistent with results from previous research, older compared to younger children's reports were more complete and accurate. Abused and nonabused children performed similarly with several exceptions: Nonabused children were more accurate in answering specific questions, made fewer errors in identifying the unfamiliar adult in a photo identification task, and (at least for younger boys) freely recalled more information. Most effects remained when group differences in IQ and behavioral symptomology were statistically controlled. Importantly, abused and nonabused children did not differ in their accuracy or suggestibility in response to questions that were relevant to abusive actions. Among abused children, however, those who suffered more severe sexual abuse made more omission errors to specific abuse-relevant questions. Contributions to psychological theory and legal implications for understanding children's eyewitness memory and testimony are discussed.     

Effects of Experiencing the Eyewitness Identification Procedure on Juror Decisions

Mistaken eyewitness identifications are believed to contribute to a preponderance of wrongful convictions, underscoring the need to identify methods to help decrease the likelihood of false convictions based on eyewitness testimony. The present study tested the hypothesis that providing jurors with first-hand experience with eyewitness identification procedures could help further sensitize them to the limitations of eyewitness testimony. Eighty college students watched a videotaped mock trial in which the prosecution’s sole evidence was eyewitness testimony. In a 2 × 2 randomized factorial design, we manipulated whether participants heard expert psychological testimony (henceforth referred to as expert testimony) on the limitations of eyewitness identification and whether they experienced an eyewitness identification procedure. As predicted, experiencing the eyewitness identification procedure had a significant impact on juror decisions, suggesting that this procedure could further help reduce the likelihood of wrongful convictions.     

The Impact of Eyewitness Expert Evidence and Judicial Instruction on Juror Ability to Evaluate Eyewitness Testimony

It has been argued that psychologists should provide expert evidence to help jurors discriminate between accurate and inaccurate eyewitness identifications. In this article we compare the effects of judicial instruction with expert evidence that is either congruent or incongruent with the ground truth, focusing on juror ability to evaluate “real” eyewitness evidence. In contrast to studies which have employed “fictional” eyewitness designs, we found no appreciable effect of either congruent or incongruent expert evidence on participant-juror sensitivity to eyewitness accuracy. We discuss the role of methodology on the inferences and conclusions that can be made regarding the impact of eyewitness expert evidence.     

Effects of Social Support on Children's Eyewitness Reports: A Test of the Underlying Mechanism

Research on children's eyewitness testimony demonstrates that interviewer-provided social support given during a mock forensic interview helps children resist an interviewer's misleading suggestions about past events. We proposed and tested 1 potential mechanism underlying support effects: Resistance Efficacy, or children's perceived self-efficacy for resisting an interviewer's suggestions. Eighty-one 6- and 7-year-old children experienced a play event, then were interviewed about the event with misleading and specific questions. Consistent with prior research, children interviewed by a supportive person were more resistant to misleading suggestions than were those interviewed by a nonsupportive person. Although Resistance Efficacy did not mediate the effects of interviewer support in the full sample, additional analyses revealed that Resistance Efficacy may be a mediator for older, but not younger, children. Contrary to predictions, children's preexisting social support reserves were not related to children's interview accuracy nor to perceived Resistance Efficacy. Implications for psychological theory are discussed, as well as implications for understanding and improving children's eyewitness reports.     

国外心理学关于证人证言的研究及其启示

证人证言在诉讼中有着极其重要的作用,但证人证言容易受到各种因素的影响,是一种很特殊的证据类型.因此,证人证言的研究成为法律心理学的热点之一.西方心理学界对证人证言进行了大量实证研究.本文首先回顾了证人证言的早期研究,然后从证人证言可靠性影响因素研究以及证人证言可靠性的评价标准两方面综述了证人证言的近期研究,并分析了其研究的意义和不足.     

国外心理学关于证人证言的研究及其启示

证人证言在诉讼中有着极其重要的作用,但证人证言容易受到各种因素的影响,是一种很特殊的证据类型.因此,证人证言的研究成为法律心理学的热点之一.西方心理学界对证人证言进行了大量实证研究.本文首先回顾了证人证言的早期研究,然后从证人证言可靠性影响因素研究以及证人证言可靠性的评价标准两方面综述了证人证言的近期研究,并分析了其研究的意义和不足.     

Simultaneous Lineups,Sequential Lineups,and Showups: Eyewitness Identification Decisions of Adults and Children

Two experiments were conducted comparing the identification accuracy of children aged 3–15 years (N = 307) and undergraduates (N = 384) using target-present and target-absent simultaneous and sequential lineups and showups. Correct identification rates tended not to vary across either age of subject or identification procedure. However, children show a significant tendency to guess as indicated by their lower rate of correct rejection when the target is absent. The tendency for children to make false positive choices was particularly evident with showups.     

Effects of Testimonial Inconsistencies and Eyewitness Confidence on Mock-Juror Judgments

This study examined the interaction between testimonial consistency and eyewitness confidence on mock-jurors' judgments of probability that the defendant committed the crime and verdicts. In a 2 (testimonial consistency) × 2 (confidence) between-groups design, 130 mock-jurors listened to an audio-taped trial of a person charged with armed robbery. Manipulations were contained in the prosecution witness's responses to detailed questioning by prosecution and defense attorneys. Although consistency is considered to be a key marker of accuracy, its impact on judgments was weak and nonsignificant. Witness confidence had a strong influence on judgments, whether testimony was consistent or inconsistent. We suggested that witness confidence may be more likely to emerge as a dominant influence on juror judgments when the testimony is wide ranging rather than relatively brief and concerned only with a specific issue (e.g., identification confidence).     

Shoot/No-Shoot Decisions in the Context of IED-Detection Training and Eyewitness Memory for Persons

Cognitive approaches to training for the detection of improvised explosive devices (IED’s) are of increasing importance. However, there is a question as to the degree to which such training might interfere with other important law enforcement (LE) functions in the field, and the degree to which such training might enhance other important cognitive/perceptual functions. A promising cognitive approach to IED training, the SMOKE system, was provided to respondents, who then responded to shoot/no-shoot decisions, important LE situations of increasing relevance. It was shown that SMOKE training did not interfere with shoot/no-shoot decisions. However, those with SMOKE training performed better than control respondents on eyewitness memory for the perpetrator of a given crime in field-valid scenes. This indicates that cognitively based training may enhance vigilance and resultant memory in field situations.     

Jurors' Use of Hearsay Evidence: The Effects of Type and Timing of Instructions

To examine the effects of curative judicial instructions on jurors' perceptions of hearsay testimony, mock jurors (N = 180) were exposed to one of six versions of a trial that included proprosecution hearsay evidence accompanied by either disregard or limiting instructions, presented either immediately after the hearsay, at the end of the trial, or at both of these times. Also included were control conditions in which (1) the information was presented as nonhearsay (first-hand), (2) no hearsay was presented, or (3) the hearsay was presented without instructions. Results indicated that neither the hearsay nor the instructions, regardless of their form or timing, affected verdicts. In fact, findings revealed that participants may have disregarded the hearsay regardless of instructions heard. There was some evidence to suggest, however, that evaluations of other admissible evidence presented by the hearsay witness were negatively affected.     

The Effects of Motive Information and Crime Unusualness on Jurors' Judgments in Insanity Cases

This study investigated the effects of motive information and crime unusualness on mock jurors' judgments in two homicide cases in which the defendant pleaded insanity. Undergraduates (N = 371) read case information and rendered a verdict, estimated the probability that the defendant was insane, and made additional judgments about the defendant's mental state. The defendant was more likely to be judged insane if the crime was oddly committed rather than committed in a typical manner. Prosecution motive information also affected judgments; the defendant was considered more sane if the prosecution presented evidence of a strong, reasonable motive. Evidence of a crazy, unreasonable motive, presented by the defense, caused jurors to see the defendant in one of the cases as more insane.     

The Mitigating Effects of Suspicion on Post-Identification Feedback and on Retrospective Eyewitness Memory

Three studies examined procedures for reducing the post-identification feedback effect. After viewing a video event, participants were then asked to identify a suspect from a target-absent photo lineup. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. Some participants who received confirming feedback were also given reasons to entertain suspicion regarding the motives of the lineup administrator, either immediately (Experiment 1) or after a one-week retention interval (Experiment 2). Suspicious perceivers failed to demonstrate the confidence inflation effects typically associated with confirming post-identification feedback. In Experiment 3, the confidence prophylactic effect was tested both immediately and after a one-week retention interval. The effect of confidence prophylactic varied with retention interval such that it eliminated the effects of post-identification feedback immediately but not after a retention interval. However, the suspicion manipulation eliminated the post-identification feedback effects at both time intervals. Both theoretical and practical implications are discussed.     

A Meta-Analytic Review of the Effects of High Stress on Eyewitness Memory

In the past 30 years researchers have examined the impact of heightened stress on the fidelity of eyewitness memory. Meta-analyses were conducted on 27 independent tests of the effects of heightened stress on eyewitness identification of the perpetrator or target person and separately on 36 tests of eyewitness recall of details associated with the crime. There was considerable support for the hypothesis that high levels of stress negatively impact both types of eyewitness memory. Meta-analytic Z-scores, whether unweighted or weighted by sample size, ranged from –5.40 to –6.44 (high stress condition–low stress condition). The overall effect sizes were –.31 for both proportion of correct identifications and accuracy of eyewitness recall. Effect sizes were notably larger for target-present than for target-absent lineups, for eyewitness identification studies than for face recognition studies and for eyewitness studies employing a staged crime than for eyewitness studies employing other means to induce stress.     

Instruction Bias and Lineup Presentation Moderate the Effects of Administrator Knowledge on Eyewitness Identification

Pairs (N = 234) of witnesses and lineup administrators completed an identification task in which administrator knowledge, lineup presentation, instruction bias, and target presence were manipulated. Administrator knowledge had the greatest effect on identifications of the suspect for simultaneous photospreads paired with biased instructions, with single-blind administrations increasing identifications of the suspect. When biased instructions were given, single-blind administrations produced fewer foil identifications than double-blind administrations. Administrators exhibited a greater proportion of biasing behaviors during single-blind administrations than during double-blind administrations. The diagnosticity of identifications of the suspect in double-blind administrations was double their diagnosticity in single-blind administrations. These results suggest that when biasing factors are present to increase a witness’s propensity to guess, single-blind administrator behavior influences witnesses to identify the suspect.     

Social Influence in Eyewitness Recall: A Meta-Analytic Review of Lineup Instruction Effects

Past research has considered the impact of biased police lineup instructions upon eyewitness lineup performance. Biased instructions either suggest to the eyewitness that the perpetrator is in the lineup or otherwise discourage a no choice response. A meta-analysis of 18 studies was employed to review the hypothesis that biased instructions lead to greater willingness to choose and less accurate lineup identifications than do unbiased instructions. The role of moderating variables in the instruction procedure was also considered. In support of the hypothesis, a significantly higher level of choosing followed biased instructions. Lineup type moderated performance accuracy, however. For target-absent lineups the increased level of choosing following biased instructions resulted in reduced identification accuracy. Biased instructions within a target-present lineup generated a higher level of confidence, but had minimal impact on accuracy. Implications for police practice are discussed.