This paper investigates extreme biases in group sensemaking through a longitudinal field study in a martial arts community. It is observed that an incremental, self-reinforcing process can cause a group’s mental model to drift away from reality. This causes significant problems when the group members interact with people who do not share the biased mental model. More specifically, as the outsiders do not react according to the biased model, the biased insider’s actions will result in undesired, harmful outcomes. Specific mechanisms, which together constitute the bias producing process are identified. Key elements include verbal persuasion by believers, social proof bias, placebo effects, and retrospective sensemaking. It is discussed how analogical dynamics can be present in business settings and argued that constant reality checks with outsiders can help groups to avoid this self-harming tendency and, therefore, foster survival and success.
Keywords: bias, sensemaking, groups, social construction, groupthink, mental model