For exposure to be effective it needs to be predictable and should be under the individual's control. In other words, throwing a spider at somebody who has a fear of spiders is unlikely to help the person to overcome the spider phobia. In fact, there is evidence that unpredictable exposure can help to maintain or increase the intensity of the phobia. In addition, for exposure to be effective it should be repeated frequently, it should be prolonged, and the individual should try not to fight his or her feelings of fear. Fighting the fear often makes it worse.
Exposure can also be gradual.
The person doesn't have to go right to the worst thing he or she can imagine. Exposure can begin with items, objects or situations that are lower on the fear hierarchy and can gradually progress to more and more difficult situations as the fear improves. Mastery of your specific phobia, therapist guide. The Psychological Corporation. I am one of those guys who has more air miles accumulated than I could ever use in a lifetime.