Exposure-based therapies reflect a variety of behavioral approaches that are all based on exposing the phobic individuals to the stimuli that frighten them. From a behavioral perspective, specific phobias are maintained because of avoidance of the phobic stimuli so that the individual does not have the opportunity to learn that they can tolerate the fear, that the fear will come down on its own without avoiding or escaping, and that their feared outcomes often do not come true or are not as terrible as they imagine. Avoidance can occur either by not entering a situation at all or by entering the situation but not experiencing it fully (e.g., because of consuming alcohol before taking a flight for a person with flying phobia). Exposure therapies are thus designed to encourage the individual to enter feared situations (either in reality or through imaginal exercises) and to try to remain in those situations. The selection of situations to try typically follows an individually-tailored fear hierarchy that starts with situations that are only mildly anxiety-provoking and builds up to the most feared encounters, though in some forms of exposure therapy (e.g., implosion therapy), the individual starts out being exposed to a very anxiety-provoking stimulus rather than building up to that point more gradually.