Adolescents' performance on delay and probability discounting tasks: Contributions of age, intelligence, executive functioning, and self-reported externalizing behavior

Healthy adolescents, ages 9-23, completed delay and probability discounting tasks and measures of verbal and non-verbal intelligence, executive functioning, and self-reported internalizing and externalizing behavior. Delay but not probability discounting decreased with age. Delay discounting was also associated with verbal intelligence and Go-NoGo and Iowa Gambling Task performance. Probability discounting was associated only with externalizing behavior. Findings conform to an accumulation of evidence that while delay and probability discounting may have some overlapping components, they also reflect some fundamentally different processes in this age group. (c) 2007 Elsevier Ltd. All rights reserved.