Crowd Psychology and Crowd Dynamics
Crowds are not simply many individuals; they develop their own norms, roles, and information channels. Candidates must understand deindividuation (reduced personal accountability in a group), social identity (people act as members of a group, so treating the group with respect matters), and emotional contagion (arousal spreads faster than information). Learn the difference between a casual crowd (low purpose, high turnover), a cohesive crowd (shared identity, e.g. a supporters' group), and an expressive or hostile crowd.
Density matters more than headcount. At roughly 4–5 persons per square metre movement becomes difficult; beyond that, individuals lose control of their own movement and pressure propagates through the crowd. Crowd crush is caused by density and pressure, not by panic or stampede behaviour - a key trap, since questions often offer "panic" as the cause of crushing. People generally behave rationally and helpfully; the danger is the physics of the crowd, not mass hysteria.
Watch for critical points: bottlenecks, merges, stopped queues, and sudden reversals of flow. A crowd that stops moving at a pinch point builds pressure behind it. Communication must be simple, repeated, and delivered from a visible, calm source; rumour fills any information vacuum.
Rule of thumb: manage density before you manage behaviour. Reduce the number of people entering a space before you try to change how they feel.
Worked example: A queue stops at a single gate. Pressure builds unnoticed 30 metres back. The correct response is to open a second entry point and split the flow, not to shout at the front of the queue.