I think the Cornell study that linked autism with a big rise in TV viewing has some merit.
The growing brain can be over-stimulated and that can result in autism.
I spent my childhood in the jungles of SA, we had no TV and I never saw a single child who was autistic.
http://www.johnson.cornell.edu/faculty/profiles/waldman/autpaper.html
There are some interesting observations in that study. Studies that correlate "autism" diagnoses with attachment-disorder behaviors are also interesting; there's a lot of overlap.