Bias in Jurors vs Bias in Juries: New Evidence from the SDS Perspective

Prior research by Kaplan and Miller (1978) suggested that juries are generally influenced less by extralegal, biasing information than individual jurors are. A social decision scheme (SDS) analysis of this question by Kerr, MacCoun, and Kramer (1997) suggested (a) that Kaplan and Miller's conclusion should hold only for relatively extreme legal cases (i.e., cases where the probability of conviction, without biasing information, was either very high or very low) and (b) that the opposite pattern should hold for moderate cases (with moderate conviction rates)—i.e., juries should show even greater sensitivity to biasing information than should individual jurors. An experiment is reported that compared juror vs jury sensitivity to biasing information (viz., prejudicial pretrial publicity) for versions of a legal case with a moderate and an extreme conviction rate. Consistent with the SDS analysis, juries were more biased than jurors for the moderate-case version, but the reverse was true for the extreme-case version. The implications of these findings and the more general utility of the SDS model for studying group processes are discussed.