Temporal Discounting of Hypothetical Monetary Rewards by Adolescents, Adults, and Older Adults

The present experiment examined temporal discounting across 3 different age bands: adolescents, adults, and older adults (mean ages 14, 46, and 73 years, respectively). A computerized task was employed in which participants were asked to choose between larger rewards available at a specified time in the future—either £100 or £1,000 (approximately $200 and $2,000, respectively)— or a smaller reward available immediately. The subjective value of the reward decreased with increasing delay for each of the 3 age groups. A hyperbola-like function adequately described the group discounting data. The adolescent group discounted significantly more than the adult group when the larger later reward (LLR) was £100 but not when the LLR was £1,000. The adolescents discounted significantly more than the older adult group when the LLR was either £100 or £1,000. There were no significant differences in discounting between the adult and older adult groups. The results of the present study suggest that the rate of temporal discounting is higher in adolescents than in adults but is stable from middle adulthood to older adulthood. Furthermore, the process of temporal discounting appears to be quantitatively similar across the life span.