Past Wins Increase Risk Taking in Humans and Monkeys

Researchers have developed a model, called "dynamic prospect theory," that integrates prospect theory and reinforcement learning theory to more accurately describe human and monkey decision-making under uncertainty. The study found that after experiencing an outcome larger than the expected value of the chosen option, participants and monkeys behaved as though the probability of winning in the next lottery increased. This change in behavior appears to be driven by a change in the perception of probabilities, not by a change in the valuation of rewards. The model provides a unified theoretical framework for exploring a neurobiological model of economic choice in human and nonhuman primates.