Predicting guilt judgments and verdict change using a measure of pretrial bias in a videotaped mock trial with deliberating jurors

Abstract

One important limitation of previous research involving measures of bias is that they rely heavily on brief methods of conveying trial information (case summaries) and participants typically do not deliberate as juries before rendering verdicts. In the present study, 183 jury-eligible college students completed the Pretrial Juror Attitudes Questionnaire (PJAQ) and the Juror Bias Scale, watched a videotaped simulated armed robbery trial, and rendered verdicts both before and after deliberating as juries. The results indicate that the PJAQ, and especially the subscales of System confidence and Conviction proneness, significantly predicts pre-deliberation verdicts as well as verdict change (i.e. the shift in verdicts from pre-to post-deliberation). Moreover, the PJAQ provides incremental predictive validity over a more commonly used measure of pretrial bias (the Juror Bias Scale) for pre-and post-deliberation verdicts, as well as providing incremental predictive validity with respect to a juror's tendency to change his/her verdict as a function of the deliberation process. Specifically, bias is associated with a greater probability of verdict change, regardless as to whether that bias reflects a pro-prosecution or pro-defense position. The implications these results have for the importance of pretrial attitude on juror judgments and the deliberation process are discussed.

Behind closed doors: the effect of pretrial publicity on jury deliberations

“…Social science research suggests that the courts may hold an overly optimistic view of the jury's ability to correct errors, reduce bias, and follow judicial instructions (Bornstein, Whisenhunt, Nemeth, & Dunaway, 2002;Lecci & Myers, 2009;Studebaker & Penrod, 1997). For example, research has found that mock-jurors typically discuss PTP during deliberations even when admonished not to (Davis, 1986;Kline & Jess, 1966).…”

Predicting verdicts, adherence to judge's instructions, and assumptions about the disposition of the defendant in a case involving the insanity defense

“…Moreover, research indicates that when more realistic trial stimuli are employed (i.e. a videotaped trail), the PJAQ can account for upwards of 21% of the variance in juror verdicts (Lecci & Myers, 2009a), and this compares favorably to other measures of pretrial bias (for a broad review of this literature see Lecci & Myers, 2009b). However, to date, the PJAQ has not been used to predict verdicts in trials involving the insanity defense.…”

“…The PJAQ has been shown to predict verdicts across a range of case summaries with varying levels of evidence, it predicts verdicts in videotaped trials, and it provides incremental predictive validity over other measures of pretrial bias, such as the Juror Bias Scale and the Revised Legal Attitudes Questionnaire (see Lecci & Myers, 2008, 2009a, 2009b.…”

Predicting verdicts using pre‐trial attitudes and standard of proof

“…Because these did not overlap with any previous juror attitude measure, Lecci and Myers concluded that they reflect important new measures of juror bias. Lecci and Myers () found that the PJAQ accounted for a greater proportion of pre‐ and post‐deliberation verdicts, respectively, after statistically controlling for the JBS subscales.…”

“…First, given past research, we expected that both BRD interpretations and juror pre‐trial attitudes would independently influence verdicts. Following Lecci and Myers (), we expected that the PJAQ would have greater predictive validity compared with the JBS and RLAQ‐23 (see also Lecci & Myers, ). Second, based on the findings of Dhami (), we did not predict that the DR and MF methods would have differential predictive validity.…”