Proceedings of the Annual Meeting of the Cognitive Science Society

Human decision-making is influenced by many factors, including uncertainty and novelty. Although widely studied, prior findings on these two secondary effects remain mixed, partly due to the confounding effect of reward value and the natural co-occurrence of uncertainty and novelty, which makes it challenging to disentangle them. To examine the unique contributions of uncertainty and novelty across age groups, we designed a two-armed bandit task that carefully controlled reward value and subjective uncertainty. On each trial, participants chose between two options varying systematically in perceptual novelty and objective uncertainty. Participants included 38 children (ages 4–6) and 37 undergraduates. By holding one factor constant while manipulating the other and applying a computational model to trial-by-trial choices, we found that children's decisions were primarily driven by perceptual novelty, while adults were guided by aversion to objective uncertainty. These findings highlight developmental changes in decision-making and offer directions for future research.