Answer:
Herd behaviour happens when people (as a crowd or collectively) make decisions that they would not make as individuals.
An example would be the decision of people to stage riots which involve the looting and destruction of property. Many of the people involved in such are decent citizens who probably have no record of crime with the state.
But because they feel that the chances of them being apprehended in a malicious crowd is very minimal, the herd instinct kicks in, leading them to make primal decisions.
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