Economic risk proneness is displayed by human children and some nonhuman primate species. To explore the role of attraction toward the unknown and the unexpected in economic choices, 2.5-year-old children and capuchin monkeys were presented in Experiment 1 with a gambling task in which participants had to choose between 2 options, a secure option and a risky option characterized by an unexpected event. In contrast to capuchins, toddlers showed a strong preference for the risky option over the safe option. In Experiment 2, toddlers maintained their risky choices despite the increased salience of the safe option. In contrast to toddlers, capuchins preferentially chose the safe option in this second experiment. We argue that capuchins' risk aversion reflects an exploitation strategy of known and safe options. In human children, the attractiveness of uncertain reward appears to be linked to their novelty seeking. We argue that toddlers' risk proneness in the gain domain reflects an exploratory search strategy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).