And... (In order to make the link between this and the topic of the thread explicit)...

What I'm considering here is that instead of the relationship between pornography and sexual abuse being one of relatively straightforward causation (in aboriginal populations at any rate) it might be more that factors like poverty, lack of health care, lack of education, living in places with sewerage run-off and possibly no electricity, not having police in the area to report crimes to, not having employment prospects etc etc etc... all jointly contribute towards social ills like sexual abuse AND viewing pornography AND alchoholism etc etc etc.

(though i guess i'm begging the question with respect to whether porn is indicative of a sickness at the social level)