Previous studies have shown that one can exploit “wisdom ofcrowds” by oneself. This is achieved by aggregating multiple“quasi-independent” estimates from the same person. However,previous methods were not necessarily easy to utilize. Therefore,we propose an efficient method based on perspective-taking. Theprocedure is as follows: First, one makes her/his own estimation.Second, one estimates again based on a different perspective(“general public”). Then these two estimations were averaged.Two experiments revealed that our method effectively induced thewisdom of crowds by oneself. More importantly, participants inour method made estimations more quickly than those in apreviously proposed method, suggesting that our method requireda relatively diminished cognitive load for participants. Furtherinvestigation suggested that our method was immune to adverseeffects of confidence. Therefore, the present findings show that ourmethod could be effective and efficient method for inducing thewisdom of crowds in one mind.

Previous studies have shown that people can make adaptive in-ferences based on memory-based simple heuristics such asrecognition, fluency, or familiarity heuristic. In the presentstudy, we discussed the adaptive nature of memory-based sim-ple heuristics in a group decision making setting. In particular,we examined how the diversity of memory affected group de-cision making when group members were assumed to make in-ferences based on the familiarity heuristic. We predicted that,when the group members’ memories were diverse, group deci-sion making would become more accurate. To examine thisprediction, we conducted a behavioral experiment and com-puter simulations, and our results generally supported the pre-diction. We discuss the role of diverse memories in generatingadaptive group decision making.