Newswise — Juries that include white and black members are likely to exchange more information about the details of a case than all-white juries, a process that may lead to more detailed deliberations and fairer verdicts, according to a study that examined racial composition and group decision making in a mock jury scenario. This finding is reported on in the April issue of the Journal of Personality and Social Psychology.

The findings also suggest that minority members' input isn't the only reason for the wider ranging discussions of diverse groups. White study participants who were part of the diverse juries were more willing to discuss racism and accurately cited more case facts than those in all-white groups, possibly because they were motivated to avoid racial bias, the study authors suggests.

This study implies that racially diverse groups may be more thorough and competent than homogeneous ones, says study author Samuel R. Sommers, PhD, assistant professor of psychology at Tufts University. "Diversity, at least in a group decision-making context, has some real benefits--and for everyone in the group," says Sommers.

In the study, Dr. Sommers recruited 121 participants from the jury pool at a Michigan county courthouse and another 79 jury-eligible participants through newspaper advertisements. Sixty percent were female; 40 percent were male; 83 percent were white and 17 percent were black. Participant ages ranged from 18 to 78 years old. Sommers randomly assigned the participants to six-person juries that were either all-white or consisted of two black and four white members. Most of the juries also had an alternate member.

Half the juries received a voir dire questionnaire that asked race-relevant questions, such as "Do you have any biases or prejudices that might prevent you from judging an African-American defendant fairly?" or "In your opinion, how does the race of a suspect affect the treatment he/she receives from police?" The other half received a racially neutral questionnaire that assessed demographic information that included questions about participants' legal experience " whether they had testified at a trial or been a victim of a crime. A trial's voir dire procedure involves questions to prospective jurors about their personal experiences and attitudes in order to determine their impartiality. The participants were shown a 30-minute Court TV video summarizing the trial of a black defendant charged with sexual assault of white victims. Jury instructions were given and then each jurist was polled privately on whether they thought the defendant was guilty before deliberations began. About 34 percent of the participants who completed the race-relevant voir dire questionnaire said the defendant was guilty before deliberation, compared with 47 percent of those in the race-neutral condition.

Furthermore, 34 percent of whites in the diverse groups said the defendant was guilty, compared with about 50 percent of those in all-white groups suggesting that white jurors' knowledge that they would debate the case in a diverse group affected their opinions even before deliberation began. The findings also suggest that even if voir dire does not screen out biased individuals, it still may influence prospective jurors by reminding them to keep their judgments free from prejudice.

After the 60 minute time allotted to deliberate a verdict, one all-white jury in the race-relevant questionnaire condition reached a unanimous guilty verdict. Sixteen groups reached a unanimous not-guilty verdict, and 12 groups did not reach a verdict at all. Additional data indicated that the diverse groups deliberated for longer than the all-white juries and discussed significantly more case facts, largely because white members raised more case facts in these groups than white participants in the homogeneous groups. The participants in the diverse groups also made fewer inaccurate statements about the case than their peers in the all-white groups.

Only five of the 14 all-white groups mentioned racism during their deliberations, said Sommers, and in each instance at least one participant minimized the importance of the issue and tried to change the subject. In the diverse groups, resistance to discussing racism occurred in only two of the nine groups that discussed the topic.

These results show that diversity influences group decision-making in multiple ways, and not just through the minority members' contributions, said Sommers. The findings indicate that jury-selection procedures that undersample minorities because of attorneys' use of tactics such as peremptory challenges to eliminate jurors of a particular race may be especially detrimental to the court system and lead to suboptimal jury performance, said Sommers.

Article: "On Racial Diversity and Group Decision-Making: Identifying Multiple Effects of Racial Composition on Jury Deliberations," Samuel R. Sommers, Tufts University; Journal of Personality and Social Psychology, Vol. 90, No.4.

Full text of the article is available from the APA Public Affairs Office or at

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 150,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.

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Journal of Personality and Social Psychology (Apr-2006)