Does expert psychological testimony inform or influence juror decision making? A social cognitive analysis.

Kovera, M. B., Borgida, E., Gresham, A. W., Gray, E., & Regan, P. C. (1997). Does expert psychological testimony inform or influence juror decision making? A social cognitive analysis. Journal of Applied Psychology, 82, 178-191.

The authors examined whether expert testimony serves an educational or a persuasive function. Participants watched a simulated sexual abuse trial in which the child witness had been prepared for her testimony (i.e., she was calm, composed, and confident) or unprepared (i.e., emotional, confused, and uncertain). The trial contained different levels of expert testimony: none, standard (i.e., a summary of the research), repetitive (i.e., standard testimony plus a 2nd summary of the research), or concrete (i.e., standard testimony plus a hypothetical scenario linking the research to the case facts) testimony. Repetitive testimony bolstered the child’s testimony, whereas concrete and standard testimony did not. Concrete testimony sensitized jurors to behavioral correlates of sexual victimization; standard and repetitive testimony desensitized jurors to these correlates. Implications for the use of procedural innovations in sexual abuse trials are discussed.

Expert testimony (standard, repetitive, concrete) influenced conviction rates, frequency of discussion regarding the victim’s motivation, and behavior and testimony during deliberation; jurors exposed to a repetitive expert recalled testimony better and were more likely to prefer conviction.

http://www.ncbi.nlm.nih.gov/pubmed/9119796