Abstract:
This study examined the effect of deliberation, presence of an intelligence quotient (IQ) score of 76 in the claimant's history, and evidence presentation order on mock juror decisions in an Atkins case. Jurors read and heard a transcript based on a real Atkins case and were asked to determine if the claimant has intellectual disability (ID) and the degree to which they were convinced the claimant has ID. Jury deliberation was manipulated on two levels (deliberation and no deliberation); an IQ score of 76 in the claimant's history (high prior IQ) was manipulated on two levels (presence and absence); and evidence presentation order was manipulated on two levels (IQ evidence first with adaptive behavior (AB) evidence second and AB evidence first with IQ evidence second). Three possible moderating variables were studied (need for cognition (NFC), legal authoritarianism, and endorsement of negative attitudes toward and stereotypes about individuals with ID). A total of 209 mock jurors were divided into 40 juries with each jury consisting of five to eight jurors. Linear mixed modeling revealed that juries that deliberated were more convinced the claimant has ID than juries that did not deliberate. Analyses also indicated that there was a primacy effect for the IQ evidence but not the AB evidence. There was also an interaction between NFC and presence of a high prior IQ. In the absence of a high prior IQ, high-NFC and low-NFC individuals were equally convinced the claimant has ID. With a high prior IQ, high-NFC individuals were less convinced the claimant has ID than low-NFC individuals. Deliberation also reduced endorsement of stereotypes. These findings suggest that there may be group processes occurring during deliberation that reduce group bias.
