What do we really know about witness preparation?

Witnesses often meet with an attorney or witness preparation specialist before trial to review, discuss, and sometimes modify the substance and delivery of their anticipated testimony. This process is commonly referred to as witness preparation. During witness preparation, witnesses are taught to use effective testimony delivery skills (e.g., verbal and nonverbal communication skills) so that they will be perceived as being credible and persuasive in the courtroom. Although social scientists know much about communication skills, credibility, and persuasion, few published studies have attempted to determine whether or not these factors can be modified through witness preparation training. The present article reviews the psychological literature pertaining to witness preparation and makes recommendations for needed witness preparation research.     

The Observed Witness Efficacy Scale: a measure of effective testimony skills

Despite advances in the scientific methodology of witness testimony research, no sound measure currently exists to evaluate perceptions of testimony skills. Drawing on self‐efficacy and witness preparation research, the present study describes development of the Observed Witness Efficacy Scale (OWES). Factor analyses of a mock jury sample yielded a two‐factor structure (poise and communication style) consistent with previous research on witness self‐ratings of testimony delivery skills. OWES subscales showed differential patterns of association with witness credibility, witness believability, agreement with the witness, and verdict decision. Juror gender moderated the impact of communication style, but not poise, on belief of and agreement with the witness. Results are discussed with attention to application of the OWES to witness research and preparation training.     

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.     

How jurors use and misuse character evidence

The Federal Rules of Evidence allow defendants to offer testimony about their good character, but that testimony can be impeached with cross-examination or a rebuttal witness. It is assumed that jurors use the defense's character evidence (CE) to form guilt and conviction judgments but use impeachment evidence only to assess the character witness's credibility. Two experiments tested these assumptions by presenting mock jurors with various forms of CE and impeachment. Participants made trait ratings for the character witness and defendant and guilt and conviction judgments. Positive CE did not affect guilt or conviction judgments, but cross-examination caused a backlash in which judgments were harsher than when no CE was given. Using path analysis, the authors tested a model of the process by which CE and impeachment affect defendant and witness impressions and guilt and conviction judgments. Implications for juror decision making are discussed.     

Motivational Bias in Criminal Investigators' Judgments of Witness Reliability1

An experiment was conducted where experienced criminal investigators (N = 49) evaluated the testimony of a witness who either confirmed or disconfirmed the focal hypothesis in a homicide case. Participants' motivation to perpetuate the hypothesis was manipulated by varying the need for cognitive closure via time pressure. The hypothesis‐inconsistent witness was perceived as less reliable and credible, although its background and witnessing conditions were identical to those of the hypothesis‐consistent witness. While this asymmetrical skepticism was not moderated by time pressure, participants under high (vs. low) time pressure were less inclined to adjust their confidence in the hypothesis in line with the witness testimony. Discussion focuses on implications for criminal investigations and theoretical contributions to investigative psychology.     

An Aiibi Witness' Influence on Mock Jurors' Verdicts1

The impact of alibi testimony on juror decision making is not yet clear because it has been examined empirically infrequently. This study was designed to determine the impact of alibi witness' testimony, the impact of an alibi witness with a relationship in comparison to one without a relationship to the defendant, and the impact of an eyewitness' confidence on juror decision making. Results indicated that mock jurors acquit a defendant more often when an alibi witness with no relationship to the defendant testified on his behalf. Participants did not believe an alibi witness who had a relationship with the defendant even though the witness was not a family member. Implications for these results are discussed.     

‘So Help Me God’? Does oath swearing in courtroom scenarios impact trial outcomes?

In countries such as Britain and the US, court witnesses must declare they will provide truthful evidence and are often compelled to publicly choose between religious (“oath”) and secular (“affirmation”) versions of this declaration. Might defendants who opt to swear an oath enjoy more favourable outcomes than those who choose to affirm? Two preliminary, pre-registered survey studies using minimal vignettes (Study 1, N = 443; Study 2, N = 913) indicated that people associate choice of the oath with credible testimony; and that participants, especially religious participants, discriminate against defendants who affirm. In a third, Registered Report study (Study 3, N = 1821), we used a more elaborate audiovisual mock trial paradigm to better estimate the real-world influence of declaration choice. Participants were asked to render a verdict for a defendant who either swore or affirmed, and were themselves required to swear or affirm that they would try the defendant in good faith. Overall, the defendant was not considered guiltier when affirming rather than swearing, nor did mock-juror belief in God moderate this effect. However, jurors who themselves swore an oath did discriminate against the affirming defendant. Exploratory analyses suggest this effect may be driven by authoritarianism, perhaps because high-authoritarian jurors consider the oath the traditional (and therefore correct) declaration to choose. We discuss the real-world implications of these findings and conclude the religious oath is an antiquated legal ritual that needs reform.     

Effects of Testimonial Inconsistencies and Witness Group Identity on Mock‐Juror Judgments1

We examined the interaction of testimonial consistency and witness group identity on mock jurors' judgments of witness effectiveness, probability that the defendant committed the crime, and verdict. In a 3 × 2 (Witness Group Identity × Testimonial Consistency) between‐groups design, 180 mock jurors heard a trial of a person charged with assault. Although both variables affected judgments, group‐identity effects were weak when testimony was characterized by inconsistencies, and they were stronger when testimony was internally consistent but ambiguous. The judgment patterns were consistent with predictions from Chaiken, Liberman, and Eagly's (1989) heuristic‐systematic processing theory, suggesting that heuristic processing would bias systematic processing when the evidence was not decisive.     

The effects of neuroimaging and brain injury on insanity defenses

Although neurological evidence is used with increasing frequency in criminal trials, there is limited research examining the effects that this evidence has on juror decision-making in insanity trials. Participants (396) were presented with a case summary and psychological testimony and asked to render either a verdict of guilty or not guilty by reason of insanity in a 2 (psychosis or psychopathy) x (presence or absence of an MRI indicating a brain lesion) x (presence or absence of testimony describing a car accident that caused injury to the brain) factorial design. Defendants diagnosed with a psychotic disorder, defendants who could demonstrate the existence of a brain lesion via MRI, and defendants who had a history of brain injury were more likely to be found not guilty by reason of insanity than those defendants who did not present any neurological testimony. Participants who reported they were more influenced by the psychological and neurological testimony were almost six times more likely to render a verdict of NGRI than those participants who reported that the psychological and neurological testimony and evidence did not influence their decision regarding verdict.     

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.     

The Impact of Defendant Gender and Relationship to Victim on Juror Decisions in a Child Sexual Abuse Case

We examined the impact of defendant gender and relationship to victim on verdict decisions and ratings of witness believability in a case of alleged child sexual assault. Mock jurors ( N  = 256) read 1 of 4 extensive case summaries. The cases varied the gender of the defendant and his or her relationship to the child (parent or stranger). Data revealed that participants were significantly more likely to find male defendants (especially the father) guilty than female defendants. Female jurors rated the victim as more believable and the defendant as less believable than did male jurors. All mock jurors rated the victim as more believable if the defendant was male, and they saw the female defendants as more believable than the male defendants.     

Victim Impact Testimony and Juror Judgments: The Effects of Harm Information and Witness Demeanor1

Victim impact testimony (i.e., testimony concerning the harmful consequences on the victim's surviving family) was examined to determine its effect on the sentencing judgments of mock jurors. Undergraduate students (N= 293) watched a videotaped murder trial simulation, rendered verdicts, and made sentencing judgments. During the penalty phase of the trial, participants were either given no victim impact testimony, or they were given victim impact testimony that varied both the severity of the harm information (mild harm/ severe harm) and the demeanor of the witness (low affect/high affect). The results indicate that information concerning the harm experienced by the victim's relatives, not the affective demeanor of the witness, influenced sentencing judgments. Implications for the U.S. Supreme Court decision in Payne v. Tennessee (1991) are discussed.     

Effects of Mental Health and Neuroscience Evidence on Juror Perceptions of a Criminal Defendant: the Moderating Role of Political Orientation

Several recent studies have examined the effects of mental health and neuroscientific evidence on attitudes toward criminal defendants, suggesting that these factors may influence juror decision‐making in meaningful ways. Few studies to date have manipulated both of these variables while also considering theoretically important individual difference variables (e.g., political orientation). Using a criminal case simulation, this study manipulated the presence of evidence concerning mental disorders (psychopathy and schizophrenia) and increasing levels of neuroscientific detail regarding a defendant's brain injury, and examined verdicts and sentencing recommendations in over 400 persons attending jury duty. Main effects were detected for mental health testimony and political orientation, although interactions were noted as well. More negative reactions to defendants labeled as psychopaths were relatively consistent, whereas participants who identified as liberal generally were less punitive towards a defendant identified as schizophrenic than were more conservative jurors. Consistent with other recent research, juror perceptions of the defendant's level of psychopathic traits (independent of the effects of the experimental manipulations) predicted guilty verdicts and longer sentencing recommendations. Copyright © 2016 John Wiley & Sons, Ltd.     

The Effects of Physical Attractiveness,Race, Socioeconomic Status,and Gender of Defendants and Victims on Judgments of Mock Jurors: A Meta-Analysis1

A meta-analysis of experimental research on mock juror judgments was conducted to assess the effects of physical attractiveness, race, socioeconomic status (SES), and gender of both defendants and victims to test the theory that jurors use characteristics that are correlated with criminal behavior as cues to infer guilt and to recommend punishment. In general, it was advantageous for defendants to be physically attractive, female, and of high SES, although these advantages were nil for some crimes. There were no overall effects of race on mock jurors' judgments, but the effect of defendant race on punishment was strongly moderated by type of crime. Effects of victim characteristics on jurors' judgments were generally inconsequential, although defendants were at a disadvantage when the victim was female.