Examining the role of deliberation in de-bias training

Does avoiding biased responding to reasoning problems and grasping the -correct solution require engaging in effortful deliberation or can such solution insight be acquired more intuitively? In this study we set out to test the impact of deliberation on the efficiency of a de-bias training in which the problem logic was explained to participants. We focused on the infamous bat-and-ball problem and varied the degree of possible deliberation during the training session by manipulating time constraints and cognitive load. The results show that the less constrained the deliberation, the more participants improve. However, even under extremely stringent conditions (high time-pressure and dual task load), participants still show a significant improvement. Critically, this "intuitive" insight effect persists over two months. This suggests that deliberation helps reasoners benefit from the training, but it is not indispensable. We discuss critical applied and theoretical implications.