How Crowds Walk
In the Nature article Mathematical Time Law Governs Crowd Flow, Ron Cowen discusses the curious behavior of crowds that we are all subconsciously aware of, but often find difficult to quantify and predict. Though the article provides satisfactory descriptions of the experiments conducted, the website article page provides a fascinating 3D real-time rendering of those experiments, quite beautifully visualizing the mechanics and recurring patterns in the interactions of individuals on a micro scale that together result in the observed crowd behavior on the macro scale. The article focused particularly on a single experiment, which it analyzed quite extensively. This experiment quite nicely integrates several of the principles discussed in class on how an individual makes a decision in the context of a crowd.
In the experiment, individuals are placed in a large rectangular closure. They were uniformly placed two feet away from one another, and were set to face in a random direction. Then, at the same time, everyone was asked to begin walking in whatever direction they please. Within seconds, clusters of five to ten people immediately began to form. If we were to create a graph of human-nodes, each individual’s neighbors on that graph would be those in their immediate field of view. As we have seen in class, the behavior of changing direction requires for a certain portion of those in one’s field of view for that person to align directions with theirs. To support this, the article notes how two individuals who run into each other rarely align their directions. But when an individual runs into a group of five or more people they will almost certainly change directions.
One attempt by the experimenters was to purposefully walk in groups of 2-3 against larger clusters walking in the opposite direction. Beyond a ratio between the cluster and the experimenter’s group size, the large cluster would simply dodge the experimenters and continue walking in the same path. We have seen this phenomenon in class as well, where the proliferation ratio of a certain behavior q is not large enough to penetrate a dense cluster’s r-value. The cluster is large enough to be difficult to sway with a group size previously large enough to sway a single individual.
Though the significance of the behavior of walking crowds may seem diminished in comparison to the significance of crowd behavior in the context of preventing an influenza or marketing a new trend, the presence of these fundamental principles in walking (among humans’ most subconscious behaviors) demonstrates how embedded the patterns we have seen in class are in the way that humans as individuals reason and interact when exposed to the decision of the majority.
http://www.nature.com/news/mathematical-time-law-governs-crowd-flow-1.16385