Risk in the eye of the beholder: Cognitive bias and risk assessment instruments

When judges, jurors, or mental health professionals make decisions based on the likelihood of an offender committing another crime, they should rely upon the most objective and valid information available about recidivism risk. Risk estimates based solely on intuitive judgments have been shown to be inaccurate, partly as a result of biased judgments. Risk assessment instruments are intended to aid decision-makers by providing a more objective estimate of recidivism risk. In a series of studies examining whether information from a risk assessment instrument eliminated initial, biased judgments among mock jurors, most of the effects of biased judgments were corrected. Nevertheless, bias related to mock jurors’ pre-existing, inaccurate beliefs about sexual recidivism had a significant influence on their perceptions of the likelihood of a specific offender’s likelihood of sexual recidivism. Whereas risk assessment instruments may cure some types of biased judgments, they do not appear to eliminate all forms of bias, particularly those related to pre-existing beliefs and attitudes.