Lowering barriers between polarized groups and the identity silos they inhabit can be challenging in times of crisis and uncertainty. This article overviews uncertainty-identity theory's analysis of the motivational role played by selfuncertainty in group identification and group/intergroup behavior, and focuses on how self-uncertainty can motivate zealous identification with "extremist" groups and identities. People need a clear sense of who they are to understand the world and their place within it, and to plan action and anticipate others' behavior. They strive to reduce self-uncertainty, and can achieve this by identifying with distinctive groups that have unambiguously defined social identities. Tumultuous social change can create identity threat, self-uncertainty, and alienation from and marginalization in society. To reduce self-uncertainty people zealously identify with ethnocentric, populist and xenophobic groups that are intolerant of dissent and have autocratic leaders-effectively building identity silos and walls between hyper-polarized groups. Under these circumstances breaking down walls to reconcile polarized and hostile groups and identities is a challenge. I close by outlining intergroup leadership theory, and its implications for building harmony between polarized identities-a par-This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.