Regarding child abuse in pre-modern societies, I think we often tend to see in such societies the things that we want to see, i.e. "noble savages". And what is considered abuse in one society may be a social norm or even an obligation in another society. Infanticide, genital multilation, incest, child marriage and many other things we consider distasteful are still common in many parts of the world and have their origins in venerable tradition &/or _practice_.
regards, Grant.