It is an irrational fear that is caused by classical conditioning and similar fears.
Watson and Rainer (two behavioral scientists) showed the role of classical conditioning on a child named Albert. In order to find out whether Albert is afraid of mice or not, they showed him a white laboratory mouse.
When Albert was playing with the mouse, suddenly there was a loud noise behind him. As you can guess, this sound made Albert cry. After hearing this sound with the white mouse several times, Albert was afraid of the mouse even without hearing the sound.
Albert’s fear later extended to rabbits, dogs and fur coats.
Watson correctly concluded that many fears are learned through classical conditioning. We probably learn the fear of the dentist due to the pain of dental fillings, the fear of driving due to an accident, and the fear of dogs due to being bitten by a dog.
But if the fears are caused by classical conditioning, then we can remove them with conditioning methods.
Contrastive conditioning is a method based on classical conditioning in which the fear-generating stimulus is associated with a new response that is incompatible with fear.
In this way, the conditioned response (fear) is weakened. For example, the mouse can be brought several times to a person with a phobia during a pleasurable activity such as eating milk and biscuits and playing soft music to change the behavior.