Guilt beyond a reasonable doubt: Effects of concept definition and assigned decision rule on the judgments of mock jurors.

Abstract

The concept of reasonable doubt was examined as both an individual and group decision criterion. Previous research indicates that neither criterion has an effect on verdicts. A reexamination of this research suggested that such effects might occur for cases producing maximum disagreement. An experiment was performed in which mock jurors reached individual and group verdicts for such a case. The decision criteria for individuals (judge's definition of reasonable doubt) and groups (assigned decision rule) were varied in a factorial design. As predicted, mock juries assigned a unanimity decision rule were significantly less likely to reach a verdict than juries assigned a majority rule. Minority members of juries assigned a majority decision rule were particularly dissatisfied with group deliberation. Definitional variations in reasonable doubt significantly affected both individual and group verdicts. The effects of the independent variables for the group decision-making process were also examined using a model-fitting approach to Davis' social decision scheme model.

The effects of defendant race, victim race, and juror gender on evidence processing in a murder trial

“…Clearly, juror gender is an important factor that is often neglected. Research has shown gender difference in verdict decisions with some studies finding women to be more conviction prone than men (Crowley, O'Callaghan, & Ball, 1994;Gabora, Spanos, & Joab, 1993;Kerr et al, 1976;Miller & Hewitt, 1978;Nagao & Ross, 1980). It has been demonstrated that females, relative to males, are more empathic and emotionally sensitive, tend to sympathize more with the victim, and hence render harsher penalties (Eisenberg & Lennon, 1983;Kanekar & Vaz, 1984), whereas males, relative to females, are more evidence driven in their evaluation of trial facts, identify more with the defendant, and allocate lenient decisions.…”

Effects of group decision rules on decisions involving continuous alternatives: The unanimity rule and extreme decisions in mock civil juries

“…Prompted by controversial Supreme Court rulings that permitted less-than-unanimous decisions by juries, researchers conducted many mock jury studies in the 1970s and early 1980s to examine the effects of group decision rules (e.g., Buckhout, Weg, Reilly, & Frohboese, 1977;Davis, Kerr, Atkin, Holt, & Meek, 1975;Foss, 1981;Hastie, Penrod, & Pennington, 1983;Kerr et al, 1976;Nemeth, 1977;Padawer-Singer, Singer, & Singer, 1977;Saks, 1977; see also Miller, 1989;and Vollrath & Davis, 1980, for reviews). These studies repeatedly demonstrated that requiring a unanimous decision versus something less than unanimity (e.g., two-thirds majority rule) has little effect on the final verdicts that juries return.…”

“…Despite this conceptual similarity, the SJS, Md(n À 1), and median models tend to make different predictions, and it is thus interesting to test which model is most accurate. 1 Previous research on group decision rules also led us to expect that (a) groups would deliberate longer under the unanimity rule than under majority rule (Davis et al, 1975;Foss, 1981;Kerr et al, 1976;Saks, 1977); (b) group members would be more confident about, and satisfied with group decisions under the unanimity rule than under majority rule (Kaplan & Miller, 1987;Kerr et al, 1976;Nemeth, 1977); (c) group members would feel that they were listened to more and had more influence under the unanimity rule than under majority rule (Green & Taber, 1980); (d) group members would perceive the unanimity rule as fairer, relative to majority rule, when they made decisions under the unanimity rule than when they made decisions under majority rule (Kaplan & Miller, 1987); and (e) group members under the unanimity rule would believe that the group discussion was more thorough than would group members under majority rule (Hastie et al, 1983;Nemeth, 1977). These effects were expected to occur in both experiments.…”

Scientific inquiry on how groups decide: The Davisonian approach

“…Over the next few decades, his work revealed many of the secrets of this rather mysterious decision making group. For example, it shed light on when and why the size and consensus-rule of the jury matter (Davis, Kerr, Atkin, Holt, & Meek, 1975;Kerr et al, 1976), whether it makes any difference in what order juries consider multiple charges (Davis, Tindale, Nagao, Hinsz, & Robertson, 1984), and how minorities, even small minorities of one, like the Henry Fonda character in Twelve Angry Men, sometimes manage to prevail in juries (Davis, Kerr, Stasser, Meek, & Holt, 1977). One very productive line of research focused on how seemingly minor procedural matters-e.g., whether (Davis, Stasson, Ono, & Zimmerman, 1988) or when (Davis, Stasson, Parks, & Hulbert, 1993) straw polls were taken; the order in which sequential polling of jurors was conducted (Davis, Kameda, Parks, Stasson, & Zimmerman, 1989)--could strongly influence the process and product of jury deliberation.…”