The effect of jury deliberations on jurors' propensity to disregard inadmissible evidence

The goal of this research was to examine the effect of jury deliberations on juror's propensity to disregard inadmissible evidence. Extant research is inconclusive; some research indicates that jurors do follow judicial instructions to ignore inadmissible evidence, but other research suggests that jurors do not. Two experiments examined whether jurors were affected by inadmissible evidence. The results revealed that although mock jurors were biased by inadmissible evidence prior to deliberations, the bias was tempered following deliberations. In Experiment 1, post deliberation jurors disregarded incriminating evidence that was ruled inadmissible because of due-process concerns. Experiment 2 replicated these results with less incriminating inadmissible evidence and also revealed that jurors did not accurately gauge the impact that the inadmissible evidence had on their verdicts. Theoretical and judicial policy implications are discussed.     

The Direct and Indirect Effects of Inadmissible Evidence1

College students (N= 270) assigned to six-person mock juries read summaries of a murder trial and then evaluated the defendant's guilt both before and after group discussion. The strength of the prosecution's case was manipulated, as was the inclusion of extra wiretapping evidence that favored the prosecution or the defense and was ruled admissible or inadmissible by the judge. Whether it favored the prosecution or the defense, inadmissible evidence directly biased subjects' reactions toward the defendant and indirectly biased their behaviors during the group discussions. None of these effects varied with the strength of the prosecution's case. The results also showed that the direct effects of inadmissible evidence were at least partially mediated by its indirect effects, suggesting that the process of deliberation can potentially help jurors to control the influence of inadmissible evidence on their decisions.     

A preliminary inquiry into the effect of potentially biasing information on judges and jurors in civil litigation

The American system of civil procedure presumes that judges and jurors will respond quite differently to potentially biasing material introduced into adjudicatory proceedings. Judges are assumed to possess a special capacity to control their subjective reactions to such material while jurors are perceived as incapable of such control. This article first reviews these presumptions and the differential treatment accorded judges and jurors by the system. An experiment in which judges and jurors were exposed to potentially biasing material in a civil trial is then described. The results suggest that judges and jurors may be similarly influenced by such exposure, regardless whether the biasing material is ruled admissible or inadmissible. The implications of these preliminary data—that judges may not possess the presumed special capacity to remain immune to bias—are briefly discussed.     

Aversive racism in Britain: the use of inadmissible evidence in legal decisions

The aversive racism framework (S. L. Gaertner & J. F. Dovidio, 1986 ) suggests that bias against Blacks is most likely to be expressed by Whites when it can be explained or justified along non‐racial grounds. The present experiment adopted a 2 (Evidence: admissible vs. inadmissible) × 2 (Defendant Race: White vs. Black) between subjects design, asking White participants, whose self‐reported prejudice was assessed, to judge a legal case. As predicted, increased guilt ratings and longer sentencing recommendations were forwarded for the Black (vs. White) defendant only when DNA evidence linking the defendant to the crime had previously been ruled inadmissible. This result was not qualified by self‐report racial attitudes. The implications for evidence inadmissibility in interracial contexts are considered, along with the repercussions of finding experimental evidence of aversive racism outside of North America. Copyright © 2005 John Wiley & Sons, Ltd.     

Decision‐making in civil litigation: Effects of attorney credibility,evidence strength,and juror cognitive processing

The current study examined the relationship between juror cognitive processing (measured by need for cognition [NFC]), attorney credibility, evidence strength, and civil litigation verdicts (liability, likelihood of causation, and compensatory damages). Participants (N = 446) viewed a videotaped mock civil trial in which the credibility of the attorneys and the strength of the plaintiff's evidence were manipulated. Plaintiff attorney credibility, defense attorney credibility, and strength of evidence interacted with one another for liability verdicts. In the strong evidence condition, the likelihood of a liable verdict was higher for a credible plaintiff attorney than a non‐credible plaintiff attorney when facing a non‐credible defense attorney. In the ambiguous evidence condition, the likelihood of a liable verdict was higher for a credible plaintiff attorney than a non‐credible plaintiff attorney when facing a credible defense attorney. Plaintiff attorney credibility, however, was found to be more influential on jurors’ decision‐making than case evidence for likelihood of causation and compensatory damage award decisions. Participants’ NFC also interacted with plaintiff attorney credibility. High NFC jurors were more influenced by a credible plaintiff attorney than low NFC jurors. Although these findings are counter to common findings in the NFC literature, they conform to a body of literature that supports the notion that jurors view attorney credibility as a piece of case evidence and not a peripheral cue as is often assumed. Thus, the findings indicate that attorneys do matter to the outcomes of cases. Policy and practice implications for attorneys and the courts are discussed.     

Differential Male and Female Responses to Inadmissible Sexual History Information Regarding a Rape Victim

Two experiments were conducted to assess the effects of exposure to sexual activity information regarding a rape victim. The results of the first experiment indicated that men had a greater tendency to attribute a female target person's sexual activity to dispositional causes than did women. In the second experiment, subjects read an acquaintance rape scenario suggesting that the victim had a promiscuous sexual past. They were instructed either to ignore this sexual history information when making judgments (inadmissible condition) or to use whatever information that they felt was appropriate (admissible condition). Control subjects were given no information regarding the victim's sexual past. Thus, the design was a 2 (Sex of Subject) x 3 (Information Admissibility: Admissible, Inadmissible, or Control) factorial. The results indicated: (a) When compared to those in the inadmissible condition, victim perceptions from subjects in the admissible condition were less favorable, (b) victim perceptions from male subjects were less favorable than those from female subjects, and (c) male subjects in the inadmissible condition attributed more responsibility to the victim than did the controls whereas female subjects in the inadmissible condition attributed less responsibility to the victim than did controls. Possible bases of these findings are discussed.     

The effects of complexity on jurors' verdicts and construction of evidence

One hundred twenty mock jurors heard 1 of several versions of a civil trial. The tort trial was either high or low in information load and contained evidence that either clearly favored the plaintiffs or was ambiguous. Expert witnesses testified in either technical or less technical language. Verdicts favored the plaintiffs when the evidence was clear and was presented in technical language because technical language enhanced witnesses' credibility when the evidence was clear. Although high information loads and technical language hindered evidence processing, jurors endeavored to comprehend, as indicated by the recall of more facts and alternative constructions of the evidence when that evidence was ambiguous. However. those constructions were of poorer quality, incorporating evidence of lesser probative value.     

Polygraph Testimony and Juror Judgments: A Comparison of the Guilty Knowledge Test and the Control Question Test1

The present experiment investigated the impact of the Control Question Test (CQT) and the Guilty Knowledge Test (GKT) on the verdicts of mock jurors. Although studies have indicated that polygraph evidence has little influence on jurors' verdicts (Cavoukian & Heselgrave, 1980; Spanos, Myers, Dubreuil, & Pawlak, 1992–1993), no research has previously distinguished between the different types of polygraph tests and their impact on juror verdicts. In the present study, jurors were shown a videotape of a simulated rape-murder trial that contained either CQT polygraph evidence, GKT polygraph evidence, or no polygraph evidence. No differences were found among the 3 conditions for either jury verdicts or individual juror verdicts, and jurors tended to rate both forms of polygraph testimony below other forms of equally suspect evidence, such as eyewitness testimony, in its influence on their decision-making process.     

Understanding pretrial publicity: predecisional distortion of evidence by mock jurors

Prejudicial pretrial publicity (PTP) constitutes a serious source of juror bias. The current study examined differences in predecisional distortion for mock jurors exposed to negative PTP (N-PTP) versus nonexposed control participants. According to work by K. A. Carlson and J. E. Russo (2001), predecisional distortion occurs when jurors bias new evidence in favor of their current leading party (prosecution or defense) rather than evaluating this information for its actual probative properties. Jury-eligible university students (N=116) acted as jurors in a mock trial. Elevated rates of guilty verdicts were observed in the N-PTP condition. Predecisional distortion scores were significantly higher in the N-PTP condition and reflected a proprosecution bias. The effect of prejudicial PTP on verdict outcomes was mediated by predecisional distortion in the evaluation of testimony. Results are discussed in relation to motivated decision making and confirmation biases.     

The effects of rational and experiential information processing of expert testimony in death penalty cases

Past research examining the effects of actuarial and clinical expert testimony on defendants' dangerousness in Texas death penalty sentencing has found that jurors are more influenced by less scientific pure clinical expert testimony and less influenced by more scientific actuarial expert testimony (Krauss & Lee, 2003; Krauss & Sales, 2001). By applying cognitive-experiential self-theory (CEST) to juror decision-making, the present study was undertaken in an attempt to offer a theoretical rationale for these findings. Based on past CEST research, 163 mock jurors were either directed into a rational mode or experiential mode of processing. Consistent with CEST and inconsistent with previous research using the same stimulus materials, results demonstrate that jurors in a rational mode of processing more heavily weighted actuarial expert testimony in their dangerousness assessments, while those jurors in the experiential condition were more influenced by clinical expert testimony. The policy implications of these findings are discussed.     

The Effect of Several Types of Pretrial Publicity on the Guilt Attributions of Simulated Jurors1

The experiment (N= 312) tested the effects of two types of pretrial publicity (PTP) on the guilt verdicts of simulated jurors. Heinous PTP was manipulated by varying the degree to which the lurid details of a rape-murder were presented to prospective jurors. Prejudgement PTP varied in the extent to which it implied that the defendant was the perpetrator or the rape-murder. As predicted, PTP which was high in either heinousness or prejudgment increased the females' tendency to conclude-after the trial evidence-that the defendant was guilty of the crime. The biasing effect of prejudgment PTP, however, was significant only among females categorized as being of low IQ. In contrast, neither dimension of PTF' significantly influenced the guilt verdicts of male jurors. Several possible explanations of the sex's differential vulnerability to PTP were proposed. In addition, evidence was obtained that female jurors may have been derogating the rape-murder victim and defensively minimizing the gravity of her fate, as a result of motivations to believe in a just world.     

Examining the prevalence, role and impact of evidence regarding Antisocial Personality, sociopathy and psychopathy in capital cases: a survey of defense team members

Although anecdotal case accounts suggest that evidence concerning Antisocial Personality Disorder (APD), sociopathy and psychopathy is frequently introduced by the prosecution in capital murder trials, to date there has been no systematic research to determine the actual prevalence, role, or perceived impact of such evidence in these cases. Survey data collected from attendees at a national capital mitigation conference (n=41) indicated that prosecution evidence concerning APD was quite prevalent, with "sociopath" and "psychopath" labels being introduced less frequently. Evidence concerning these disorders, which were assessed primarily via DSM criteria and self-report personality inventories, was most often introduced by the prosecution in the sentencing phase to address a defendant's ostensible risk of future dangerousness and/or to rebut mitigating evidence-although it was also introduced frequently in the guilt/innocence phase of these trials to rebut mental health evidence offered by the defense. Survey respondents believed that evidence concerning APD, sociopathy, and psychopathy had a considerable impact on trial outcomes. Also, although defense objections were common, such evidence was rarely ruled to be inadmissible in these cases.     

The Moderating Effect of Ecphoric Experience on Post‐identification Feedback: A Critical Test of the Cues‐based Inference Conceptualization

Confidence inflation from confirming post‐identification feedback is greater when the eyewitness is inaccurate than when the eyewitness is accurate, which is evidence that witnesses infer their confidence from feedback only to the extent that their internal cues are weak. But the accurate/inaccurate asymmetry has alternative interpretations. A critical test between these interpretations was conducted by including disconfirming feedback conditions. Student participants (n = 404) witnessed a mock crime, had either a strong or weak ecphoric experience when making their line‐up identifications, and subsequently received no feedback, confirming feedback, or disconfirming feedback. Consistent with a cues‐based conceptualization of the feedback effect, disconfirming feedback influenced witnesses with weak ecphoric experiences more than witnesses with strong ecphoric experiences, ironically increasing the confidence‐accuracy relation. Copyright © 2011 John Wiley & Sons, Ltd.     

Jurors' Use of Standards of Proof in Decisions about Punitive Damages

Standards of proof define the degree to which jurors must be satisfied that a fact is true, and plaintiffs in civil lawsuits assume the burden of proving their claims to the requisite standard of proof. Three standards—preponderance of evidence, clear and convincing evidence, and beyond a reasonable doubt—are used by different jurisdictions in trials involving liability for punitive damages. We investigated whether individual mock jurors apply these standards appropriately by instructing them to read two personal injury trial summaries and to use one of three standards in either qualitative or quantitative format when deciding punitive liability. Results showed that jurors tended not to incorporate the standard into their judgments: defendants were just as likely to be found liable when the plaintiff's burden was high (“beyond a reasonable doubt”) as when the burden was low (“preponderance of evidence”). The format of the instruction also had a negligible effect. We suggest that nonuse of the standard of proof is related to jurors' preferences for less effortful or experiential processing in situations involving complicated or ambiguous material. Copyright © 2012 John Wiley & Sons, Ltd.     

Nonadversarial Methods for Sensitizing Jurors to Eyewitness Evidence

Tested the effects, on juror decision making, of court-appointed expert testimony and judge's instructions designed to sensitize jurors to eyewitness evidence. Subjects ( N = 144) viewed a videotaped trial in which the primary evidence was the testimony of and identification by an eyewitness. Three levels of expert advice (court-appointed expert, judge's instructions, no expert advice) were crossed with two levels of witnessing and identification conditions and two levels of witness confidence The court-appointed expert produced skepticism toward the identification but did not improve juror sensitivity to the eyewitness evidence. The judge's instructions produced neither skepticism or sensitization effects.