Subtle Movements in Crowds Lead to Large-Scale Phenomena

Arizona State University researchers are looking into crowd behaviors, such as riots and evacuations, to gain insight into the dynamics behind them. They are developing computer-based models to better understand how an individual's action in a large crowd affects the individual's subsequent action and the actions of the crowd as a whole. The research builds virtual laboratories to experiment with ideas and theories about crowd behavior and dynamics that would otherwise be impenetrable to academic inquiry. The results may be used as a training aid for law enforcement on how to handle a panicked or violent crowd.

The research involves creating computer-simulated environments to experiment with crowd behavior and track the behavior of a single individual agent in the environment. Each agent possesses a computable "brain" that allows it to function as a distinctive individual within the broader group framework. Those conducting experiments can record and analyze each agent's behavior, activity and social and anti-social interactions, and they can explore how those behaviors adapt as conditions unfold. For example, they found that an individual's subtle stop-and-start movement amid panicked crowds caused larger waves, which then washed through the crowd, causing further obstructions and ultimately large-scale congestion. Knowing the behaviors and dynamics behind these situations enables law-enforcement officials to explore different strategies for maintaining calm and handling large crowds in an efficient manner.