Many researchers have theorized as to why and how paraphilias develop, but very little consensus has been reached. Paraphilias are undoubtedly complex behavior patterns, which may have biological, psychological, or social origins—or aspects of all three.

Biological Theories

Biological researchers have found that a number of conditions can initiate paraphiliac behavior. Men without previous paraphilias began to display paraphiliac behavior when they developed temporal lobe epilepsy, brain tumors, and disturbances of certain areas of the brain (Kreuter et al., 1998; G. Simpson et al., 2001). This does not mean that every­one with a paraphilia has one of these diseases. Researchers have found that some para- philiacs have differences in brain structure and brain chemistry and possible lesions in certain parts of the brain (Kennet, 2000). Researchers have also been studying whether higher levels of certain hormones, such as testosterone, may contribute to the develop­ment of a paraphilia (Giotakos et al., 2005). However, at most these are factors that may lead some people to be more likely to develop a paraphilia, and they do not explain the majority of paraphiliac behaviors.