A Meta-Analysis of the Effects of Jury Size

In a series of opinions in the 1970s, the U.S. Supreme Court concluded that juries smaller than 12 persons would be constitutional if they performed no differently than traditional 12-person juries. In a meta-analysis, we examined the effects of jury size on the criteria the court specified as the basis for making such comparisons. A search for all relevant empirical studies identified 17 that examined differences between 6- and 12-member juries. The total sample for the 17 studies was 2,061 juries involving some 15,000 individual jurors. Among other findings, it appears that larger juries are more likely than smaller juries to contain members of minority groups, deliberate longer, hang more often, and possibly recall trial testimony more accurately.