Herd behaviour describes how individuals in a group can act together without
planned direction. The term pertains to the behaviour of animals in herds,
flocks, and schools, and to human conduct during activities such as stock
market bubbles and crashes, street demonstrations, sporting events, episodes
of mob violence and even everyday decision making, judgement and opinion
forming.A group of animals fleeing a predator shows the nature of herd behavior. In the often cited article "Geometry For The Selfish Herd," evolutionary biologist W. D. Hamilton said each individual group member reduces thedanger to itself by moving as close as possible to the center of the
fleeing group. Thus the herd appears to act as a unit in moving together,
but its function emerges from the uncoordinated behavior of self-seeking
individualsAsymmetric aggregation of animals under panic conditions has
been observed in many species, including humans, mice, and ants.
Theoretical models have demonstrated symmetry breaking similar to
observations in empirical studies. For example when panicked individuals
confined to a room with two equal and equidistant exits, a majority will
favor one exit while the minority will favor the other.
