http://www.research.ufl.edu/publications/explore/v10n1/pdfs/pg07extracts.indd.pdf
The TV day ended early, not because of concerns for family life, but because of limited technology.
I'm willing to accept the idea, but I didn't see it in that article.
Technology or not, the conditioning element was strong in the 50's and 60's ... the subliminal seduction of the drive-in cartoon/commercials notwithstanding, e.g.