Juries that include white and black members are more likely to have in-depth discussions than all-white juries, according to a study in the April Journal of Personality and Social Psychology (Vol. 90, No. 4). However, the improved performance isn't solely due to the minority members' input: White study participants who are part of diverse juries are more willing to discuss racism and accurately cite more case facts than those in all-white groups, the results suggest.

The study implies that racially diverse groups may be more thorough and competent than homogeneous ones, says study author Samuel Sommers, PhD, a Tufts University assistant psychology professor.

"Diversity, at least in a group decision-making context, has some real benefits-and for everyone in the group," says Sommers.

Swaying opinions

In the study, Sommers recruited 121 participants from the jury pool at a Michigan county courthouse and another 79 jury-eligible participants through newspaper advertisements. Sommers randomly assigned them 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.

Next, Sommers explained a trial's voir dire procedure, in which prospective jurors are questioned to determine their impartiality. Half of the juries received a voir dire questionnaire that asked race-relevant questions, such as "This trial involves an African-American defendant and white victims. How might this affect your reaction to this trial?" The other half received a racially neutral questionnaire that assessed demographic information.

The participants then watched a 30-minute Court TV video summarizing the trial of a black defendant charged with sexual assault of white victims. Afterward, Sommers read aloud jury instructions and then polled each jurist on whether they thought the defendant was guilty before deliberations began. He found that:

  • About 34 percent of participants who completed the race-relevant questionnaire considered the defendant guilty before deliberation, compared with 47 percent of those in the race-neutral condition-data that indicate that merely raising issues of race influenced participants' opinions.

  • About 34 percent of whites in diverse groups thought 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.

Deliberation differences

The juries then had 60 minutes in which to deliberate a verdict. One group-an all-white jury in the race-relevant questionnaire condition-reached a unanimous guilty verdict. Sixteen reached a unanimous not-guilty verdict, and 12 did not reach a verdict.

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 white participants in the diverse groups also made fewer inaccurate statements about the case than their peers in the all-white groups.

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

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

"The data indicate that procedures that help ensure that juries are indeed diverse and representative of the community from which they're drawn are good things," he explains.

The study's findings could also apply to other group settings, including higher education and the workplace, says Sommers. While advocates often argue for increased diversity in these areas because they say it is the right thing to do, the study shows that diversity also may be the smart thing to do, he notes.

In particular, his study indicates that homogeneous groups in some settings spend less time on their decisions, make more errors and consider fewer perspectives. Groups that are diverse-whether in a college classroom or in a corporate boardroom-may see improved performance among all members, Sommers says.