Changing in the Reaction Time Causes the Confidence Matching in Group Decision Making

Introduction: Others’ decision could constantly affect our decisions. There are numerous studies which revealed this effect properly. The social influence could affect most of the decision parameters, especially the confidence.  Recently, an interesting study showed that participants tend to match their confidence to each other while they preserve their decision accuracy in a group decision making task. Since the decision accuracy is not able to explain this effect, the main question is which decision parameter is changing in a way which could be resulted in changing in the confidence and ultimately the confidence matching. Materials and Methods: In order to answer this question, ten subjects attended into a Psycho-Physic study with two separate sessions; Isolated and Social. In both situations, the participants were required to determine the direction of the presented motion dots and report their decision and confidence simultaneously. In the social situation, subjects were paired with four computer-generated partners, which had been created based on the data from the isolated session. The joint decisions were determined by the decision of either partner which had higher confidence. In this session, confidence and decision of the partner were represented to the participant. Results: The results indicated the subjects not only try to match their confidence to their partners, but also reported higher confidence in comparison with the isolated situation. We observed although the confidence matching did not affect the decision accuracy, however, the reaction time varied significantly in both sessions. Conclusion: This study reveals the role of reaction time in changing the confidence and consequently the confidence matching. This study once again emphasis on the reverse correlation of the reaction time and confidence even in a group decision making task.