Phobias: Irrational Fear Fear of heights, fear of the number “13,” fear of spiders, fear of small spaces. All of these fears are considered phobias. While there are many causes of phobias, one theory uses the notion of preparedness in Pavlovian conditioning. This is a way in which people learn to react to certain stimuli. Scientist and abehaviorist, Pavlov, first discovered this conditioning while experimenting with dogs. He could reliably predict that dogs would salivate when food was placed in the mouth through a reflex called the “salivary reflex” in digestion. Yet he soon realized that, after time, the sa