Habituation is a decrease in response to stimulus after repeated or prolonged exposure. Habituation can helpful or dangerous as people can become primed to react a certain way, when a series of events occur that follow the pattern they have trained for.

An example of helpful habituation is psychotherapy and the use of exposure therapy to overcome phobias or trauma by slowly exposing the person to the thing they fear.

A dangerous example of habituation is when a U.S. Navy ship fired on a civilian aircraft in the mistaken belief that it was a hostile military plane. People find what they are looking for the and the soldiers were primed to react to a hostile plane. The saying “to a man with a hammer, everything looks like a nail” is rather apt here.