Offenders have higher delay-discounting rates than non-offenders after controlling for differences in drug and alcohol abuse

Purpose. Do criminal offenders discount future rewards more rapidly than non-offenders? Theories of criminality assume that impulsivity is a key predictor of offending and suggest an affirmative answer, but there are no prior relevant studies with adult offenders and the only previous study with juveniles failed to find that offenders discounted delayed rewards more steeply than controls (Wilson & Daly, 2006). Method. We measured rates of delay discounting for adult offenders incarcerated in two medium-security facilities in New Zealand (n= 63) and non-offender controls (n= 70) using a questionnaire which asked participants to nominate an indifference point - an amount of money to be received after a delay that was equal in value to an immediate amount - for immediate rewards varying from $500 to $4,000. Indifference points were converted to annual discounting rates. Self-reported measures of alcohol and drug abuse were also obtained. Results. Offenders discounted future rewards substantially more than non-offenders, and rates varied systematically with amount and delay for both groups, consistent with previous research. The difference in delay discounting between offenders and controls remained significant after controlling for self-reported drug and alcohol use. There were no significant gender differences. Conclusions. These results suggest that offenders have a deficit in delay discounting, likely appearing in late adolescence or early adulthood, which may lead them to make suboptimal choices.