This will be a difficult topic to set up considering how great a difference there is between the UK, mainland Europe and US in TV programming but bear with me and help me out if you can make better sense of it.
I recall growing up and there were very clear age group orientated, boundaried almost, TV programming on a limited number of channels. Its not just that there were times of the day when the two main channels dedicated their broadcasting to childrens TV, with a friendly, almost paternal or maternal broadcaster who as the "face" of the broadcasting service, with the programming starting with cartoons and progressing to a "teen drama" which dealt with such pressing problems as the first kiss and making and breaking friendships. Then there was the childrens news broadcasting then the TV gave over to adult broadcasting again with the adult news broadcasts.
This sort of broadcasting has changed, the structuration is gone, although the rise of other networks and complete channels devoted to particular sorts of viewing has had a role to play. The content is there still but not the structure.
Then there is the amount of programming which deals with the topic of living, often thinly veiled as SciFi or Fantasy (both star trekk and Buffy the Vampire slayer often featured characters who where confused by humanity and trying to become human, conducting a close study of humanity). I think there's less of that sort of broadcasting now although there are repeats shown on some networks in the UK.
My question is whether TV has become a powerful form of secondary socialisation? Its become so ubiquitous that families without TVs are considered unusual, even families without a TV constantly playing in one room often in a number of rooms simultaneously are considered unusual. This being the case what about its impact? Both the content and structure of broadcasting could have a massive implication for society and the individual per se in terms of development and welfare.