Editing Phobia (section)

==== Classical conditioning ====
Much of the progress in understanding the acquisition of fear responses in phobias can be attributed to [[classical conditioning]] (Pavlovian model).<ref name="ProQuest Health and Medical Complete">{{cite journal | vauthors = Myers KM, Davis M | title = Mechanisms of fear extinction | journal = Molecular Psychiatry | volume = 12 | issue = 2 | pages = 120–150 | date = February 2007 | pmid = 17160066 | doi = 10.1038/sj.mp.4001939 | s2cid = 3364934 | id = {{ProQuest|221163409}} | doi-access =  }}</ref> When an aversive stimulus and a neutral one are paired together, for instance, when an electric shock is given in a specific room, the subject can start to fear not only the shock but the room as well. In behavioral terms, the room is a [[conditioned stimulus]] (CS). When paired with an aversive [[unconditioned stimulus]] (UCS) ''(the shock)'', it creates a [[conditioned response]] (CR) ''(fear for the room)'' (CS+UCS=CR).<ref name="ProQuest Health and Medical Complete"/> For example, in case of the fear of heights ([[acrophobia]]), the CS is heights. Such as a balcony on the top floors of a high rise building. The UCS can originate from an aversive or traumatizing event in the person's life, such as almost falling from a great height. The original fear of nearly falling is associated with being high, leading to a fear of heights. In other words, the CS ''(heights)'' associated with the aversive UCS ''(almost falling)'' leads to the CR ''(fear)''.
It is possible, however, to extinguish the CR, and reversing the effects of the CS and UCS. Repeatedly presenting the CS alone, without the UCS, can exinguish the CR.<ref>{{Cite journal |last=Vurbic |first=Drina |date=September 2011 |title=Secondary extinction in Pavlovian fear conditioning |journal=Learning & Behavior |volume=39 |issue=3 |pages=202–211 |doi=10.3758/s13420-011-0017-7 |pmid=21286897 |pmc=3117985 }}</ref>

Though historically influential in the theory of fear acquisition, this direct conditioning model is not the only proposed way to acquire a phobia. This theory in fact has limitations as not everyone that has experienced a traumatic event develops a phobia and vice versa.<ref name=":0" />