As scientists seek to understand how the disorder develops, there is growing consensus that the origin is largely biological. This view is based in part on studies pointing to subtle physical traits that have a higher incidence among pedophiles.

“The biological clues attached to pedophilia demonstrate that its roots are prenatal,” said James Cantor, director of the Toronto Sexuality Center. “These are not genetic; they can be traced to specific periods of development in the womb.”…

By contrast, the common presumption that pedophiles were themselves abused as children now has less support. Child victims are at far greater risk of future substance abuse, depression, persistent traumatic stress or criminal aggression than of becoming molesters. The vast majority of offenders deny any sex abuse in their childhood, even though they could garner sympathy in court by doing so, experts say. “A chaotic childhood increases the likelihood of a chaotic adulthood, of any kind,” Dr. Cantor said.