EXPRESS: Variable and sub-optimal responses to a choice problem persist despite experience with a simple and effective decision rule.

Choices in a focus-divide dilemma tend to be variable and suboptimal. How readily will people adopt a simple, rational choice rule to improve performance? We asked participants to choose where to stand to throw a beanbag into one of two possible hoops (Experiments 1A, 1B, 1C), and to choose where to fixate to discriminate a target that could appear in one of two possible boxes (Experiment 2). The rational choice follows a simple logic: when hoops/boxes are close together, standing/fixating near their midpoint is optimal. When hoops/boxes are far apart, standing at/fixating one hoop/box will optimize success. We attempted to nudge participants towards optimal choices by providing circumstances in which they carried out the correct solution, and then returning them to the original context to freely choose. In both experiments, participants executed optimal choices during the intervention, and then immediately returned to a sub-optimal pattern of responding when presented with the original context. Experiments 3A and 3B demonstrate the rational decision rule can be easily applied and improves performance. We conclude that variable and idiosyncratic responses are a persistent choice strategy. Borrowing concepts from classic animal learning studies, we suggest rule-following risks missing opportunities for reinforcement learning afforded by choice variability.