To model the behaviour of humans en masse, treat them as people, not molecules

Social science

Wisdom about crowds

Apr 20th 2011 | from the print edition

THE behaviour of crowds is sometimes unpredictable and occasionally deadly, but there is good reason to believe it is governed by simple rules. Presumably, like molecules in a liquid, people in a crowd all behave in more or less the same way. Capture those similarities in a model and it should be possible to predict how a crowd will behave.
Existing models of crowd behaviour do just that. They treat moving masses of humanity as though they were fluids. This works, up to a point. But it often fails to predict the changes that happen as a crowd’s density increases and its movement becomes chaotic.

Continue reading....