["Scandinavian Journal of Psychology, EarlyView. ", "\nABSTRACT\nThere is growing interest in the role of cognitive flexibility in the development of politically motivated violence and a willingness to self‐sacrifice. However, the construct of flexibility has been applied in multiple ways across disciplines, resulting in conceptual ambiguity and methodological challenges. This narrative scoping review re‐evaluated the theoretical mechanisms linking distinct flexibility constructs to extreme beliefs, with the aim of clarifying their conceptual boundaries to direct future research. A narrative synthesis was conducted to identify and integrate theoretical accounts of flexibility relevant to extreme belief formation and maintenance. Four flexibility variants were identified as relevant: cognitive, affective, psychological, and belief flexibility. Each was conceptualized as facilitating updating and switching within cold, decontextualized cognitive tasks or hot, contextualized affective tasks to enable goal‐directed problem solving. These abilities were not found to promote a single problem‐solving strategy. Rather, they enabled a range of adaptive responses, including evidence integration, critical thinking, emotion regulation, and tolerance of uncertainty. Their use was associated with effective navigation of conflicting evidence, openness to new ideas and perspectives, and reflective awareness of emotional responses and cognitive biases. The findings indicate that flexibility operates across both affectively charged and emotionally neutral cognitive processes, the activation of which depends on the emotional valence of the context. In this way, cognitive and affective flexibility appear to function as complementary protective factors against the development of extreme beliefs. Future research should examine how these forms of flexibility interact across time in belief formation and maintenance.\n"]