Time-pressure effects on performance in a base-rate task

Researchers assume that time pressure impairs performance in decision tasks by invoking heuristic processes. In the present study, the authors inquired (a) whether it was possible in some cases for time pressure to improve performance or to alter it without impairing it, and (b) whether the heuristic invoked by base-rate neglect under direct experience can be identified. They used a probability-learning design in 2 experiments, and they measured the choice proportions after each of 2 possible cues in each experiment. In 1 comparison, time pressure increased predictions of the more likely outcome, which improved performance. In 2 comparisons, time pressure changed the choice proportions without affecting performance. In a 4th comparison, time pressure hindered performance. The choice proportions were consistent with heuristic processing that is based on cue matching rather than on cue accuracy, base rates, or posterior probabilities.