Let me start with the things that were not antidotal and hence have sources you can verify. The reason I say pedophilia is genetic is because all sexual orientation is genetic.
Every animal has a sexual orientation.
If they did not they could just as easily go around humping trees to get physical stimulation and then DNA would never get reproduced. The fundamental unit of selection, and therefore of self-interest, is not the species, nor the group, nor even, strictly, the individual. It is the gene, the unit of heredity. Richard Dawkins has presented this idea best in his book the Selfish Gene. His argument is that all other animals, and we are machines created by our genes.