Age differences in intertemporal choice among children, adolescents, and adults

When choosing between sooner-smaller and later-larger rewards (i.e., intertemporal choices), adults typically prefer later-larger rewards more often than children. Intertemporal choice prefer-ences have been implicated in various impulsivity-related psy-chopathologies, making it important to understand the underlying mechanisms not only in terms of how reward magni-tude and delay affect choice but also in terms of how these mech-anisms develop across age. We administered an intertemporal choice paradigm to 60 children (8-11 years), 79 adolescents (14- 16 years), and 60 young adults (18-23 years). The paradigm sys-tematically varied amounts and delays of the available rewards, allowing us to identify mechanisms underlying age-related differ-ences in patience. Compared with young adults, both children and adolescents made fewer later-larger choices. In terms of underly-ing mechanisms, variation in delays, absolute reward magnitudes, and relative amount differences affected choice in each age group, indicating that children showed sensitivity to the same choice -relevant factors as young adults. Sensitivity to both absolute reward magnitude and relative amount differences showed a fur-ther monotonic age-related increase, whereas no change in delay sensitivity occurred. Lastly, adolescents and young adults weakly displayed a present bias (i.e., overvaluing immediate vs. future rewards; nonsignificant and trend, respectively), whereas children showed a nonsignificant but opposite pattern, possibly indicating that specifically dealing with future rewards changed with age. These findings shed light on the underlying mechanisms that con-tribute to the development of patience. By decomposing overt choices, our results suggest that the age-related increase in patience may be driven specifically by stronger sensitivity to amount differences with age. (c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/).