Temporal Patterning in Probabilistic Choice

Human subjects making repeated choices between probabilistic and near-certain monetary rewards tended to be less risk-averse the shorter the inter-trial interval. Subjects were also less risk-averse when the choice-outcome sequences were clustered in threes than when each choice-outcome sequence was separated from its neighbors by equal intertrial intervals. These results further extend the analogy between delay discounting and probability discounting. Probability discounting, like delay discounting, may be described by hyperbolic function relating discounted value to expected delay to the next reward.