)
I bet on it being exactly the same as with narcs, 25% nature, 75% nurture.
Also, the origin is besides the point. Which is "don't diddle kids".
If you have neither willpower to resist nor hobbies to distract yourself from kiddie-diddling, your place is in prison, far away from any children.
All the "but they can't restrain themselves because they're born with it" does is *promote death penalty (can't be helped - to the death row with you) and eugenics (prevent more pedos from being born by identifying the pedogene)*.