Collective crises – such as natural disasters, terrorist attacks, and pandemics – profoundly disrupt the symbolic and social frameworks that normally sustain everyday life. Sociological research has long shown that such crises often trigger waves of solidarity, communication, and collective mobilization. However, the psychological forces driving these social dynamics remain insufficiently understood. This article addresses this gap by proposing that anxiety and the social sharing of emotion constitute central psychosocial mechanisms underlying collective responses to crisis. Drawing on the theoretical framework of the social sharing of emotion and integrating empirical findings from studies conducted in interpersonal contexts, public gatherings, and digital communication environments, we examine how emotional responses shape the cognitive and social processes that unfold after disruptive events. We argue that the diffuse anxiety generated by collective crises stimulates rumination, information seeking, and extensive interpersonal communication. Through repeated social sharing, emotions propagate across social networks, synchronizing emotional experience and fostering social cohesion. Evidence from laboratory studies, field research, and large-scale analyses of digital communication demonstrates that these processes can reinforce collective beliefs, support social solidarity, and contribute to the reconstruction of meaning after disruption. In this perspective, emotional turbulence following collective crises, far from reflecting social disorganization, represents a fundamental mechanism through which societies transform emotional reactions into shared knowledge, collective memory, and renewed social cohesion.