How does the phenomenon of "crowd psychology" influence individuals' decision-making in crisis situations?

Crowd psychology examines how individuals' thoughts, feelings, and behaviors are influenced when part of a larger group. During crisis situations, such as natural disasters or public emergencies, individuals often act differently than they would if alone. The fear and uncertainty inherent in these scenarios can lead to rapid, collective decision-making that might not align with rational or individual choices. Understanding how crowd psychology operates in these contexts can shed light on human behavior and help improve strategies for managing public responses during emergencies. What are the underlying psychological mechanisms that drive this behavior, and how can they be accounted for in policy and planning?