Behaviorists suggest that paraphilias develop because some behavior becomes associated with sexual pleasure through conditioning (G. D. Wilson, 1987). For example, imagine that a boy gets an enema. While receiving it, the boy has an erection, either by coinci­dence or because he finds the stimulus of the enema pleasurable (it becomes a rein­forcement). Later, remembering the enema, he becomes excited and masturbates. As he repeats his masturbatory fantasy, a process called conditioning occurs, whereby sexual excitement becomes so associated with the idea of the enema that he has trouble be­coming excited in its absence.

You can imagine how similar situations could lead to other types of fetishes: A boy lies naked on a fur coat, or takes a “horse” ride on his aunt’s long black leather boots, or

puts on his sister’s panties, or spies on a female houseguest through the bathroom key­hole. All of these behaviors become positively reinforced and thus are more likely to be repeated.