<span>Phobias are common mental disorder (yes, they are). It is having a persistent fear of an object or a situation. The area of the brain responsible for fear is the amygdala, and problems in this area is linked to phobias. The condition should be treated as the patient is at higher risk of suicide. There are several effective treatments for phobias.</span>
I think its A sorry if im wrong
Answer: Stimulus generalization.
This is caused by fear or trauma (attacked by a fierce dog) is generalized to encompass similar stimuli (fear of all dogs, whether aggressive or not). Sometimes this effect wears off, but sometimes it will longer for years or even up to a lifetime, building into a phobia.
Hope this helps.