We grew up in a culture that believes unusual sexual desires are a psychological reaction to life events in the same way phobias and PTSD are. In 50 years I have never seen any evidence to support this belief. A psychological cause for homosexuality, trans-sexualism, and other unusual desires, has never been found. Many people here want to believe there was some external event, or series of events, that caused our ABDL desires. I no longer believe this myself because there is no evidence to support it. But there is evidence of something else: ABDL desires are not a psychological response to a childhood event, they ARE the event.
It's hard to break from traditional beliefs that these desires are a result of nurture rather than nature, but the evidence is pushing us in the direction of nature.