Evaluating layperson interpretation of actuarial sexual violence risk data: A multi-method comparison of risk communication with attention to gender bias

Abstract

Forensic clinicians are often called upon to help courts determine the likelihood that someone will continue to commit sexually violent acts in the future. The utility of these evaluations depends largely on how effectively the results are communicated to and understood by the trier of fact. Actuarial results, such as those commonly reported in sexual offense risk assessments, appear particularly challenging for laypersons to understand. Using a representative sample of 206 U.S. adults, this study examines three methods of communicating actuarial risk via simulated expert testimony on participants' ratings of a hypothetical evaluee's risk of sexual re-offending. The results suggested that all participants, regardless of how results were communicated, over-estimated the examinee's risk level relative to the expert's probabilistic findings, but tended to agree with the expert's categorical predictions. Participants who were only shown actuarial data consistently rated the evaluee as more dangerous and likely to commit future sexually violent acts. Additionally, it was found that gender significantly impacted participants' perceptions, such that women found the evaluee more dangerousness and desired greater social distance from him. This study has implications for best practices regarding expert communication of actuarial results in cases involving sexual violence.