If we go way back in time, back to ancient Rome or Egypt, or farther back, as far as you want to go, was this a problem at all? Did what we consider pedophilia cause any societal problems? Was it acceptable, and if so what problems did it cause? Is there any data on ancient societies regarding this?
Interesting question. My knowledge of history and sociology isn't strong, but I do remember learning a bit about ancient Greek society in this regard. During the time of Socrates and Aristotle, right around there, people were generally regarded as "sexual beings" starting around the age of twelve or so, I think it was, and age gaps between any two partners weren't given any consideration. It was usual for someone twelve or thirteen years old to be sexually active with people in their thirties, forties, and probably even older than that. I'm not aware of what kind of effect this had on their society per se, but obviously that period of time in ancient Greece produced a lot of advancements and breakthroughs in a variety of scientific fields and also produced a good deal of literature that is still highly regarded today.
Interesting aside, by the way... in that society, too, people were just sexual, and gender was largely considered irrelevant. Basically, everyone was bisexual to the point where it was generally just taken for granted, and those who preferred only one sex (whether it was their own or the opposite one) were regarded as being a bit "odd", although they weren't generally condemned or held in contempt.