Numerous studies have shown that numeracy is the most reliable predictor of superior financial outcomes, even after controlling for demographics, cognitive, and emotional factors. A key meta-cognitive factor explaining the difference in performance between highly and less numerate people is deliberation. Highly numerate individuals spend significantly more time than less numerate individuals to achieve significantly superior choice performance.


This study examined the impact of deliberation on decision outcomes. Specifically, the goal was to persuade decision-makers to engage in more deliberate thinking and to create a more accurate representation of the choice problem, leading to superior decisions. We manipulated the deliberation on three levels (High, Moderate, and Low) for each participant. Furthermore, we presented mixed domain binary choice problems using the Decision from Experience (DfE) task to monitor changes in decision performance as a function of different deliberation levels. In the DfE task, participants can explore outcomes by drawing random samples from each distribution. We created a numerical model that predicts the sufficient number of samples (a proxy for the deliberation period) necessary for decision makers to create distinct levels of accurate representation of the choice problem, depending on the deliberation condition.


We found that decision makers' performance (i.e., decision accuracy from a normative perspective) improved significantly with increased deliberation. In other words, the mean EV consistency in the High deliberation condition was significantly higher than in both the Moderate and Low deliberation conditions. This result remains consistent even after controlling for fluid intelligence, numeracy, or individuals with high cognitive reflection. This result conclusively demonstrates that more skilled decision makers make superior decisions primarily due to the time they spend on each problem. This result also highlights that interventions designed to motivate less numerate individuals to engage in an energy-intensive deliberate decision process will significantly improve their decision quality.