Amazingly, they’re spending just under two-and-a-half hours every day in front of the box. By the time they hit 16, they’ll be doing twice that; and even though a third of today’s kids have a PC in their rooms, by 2010, the forces of Microsoft and the TV companies will have combined the two kinds of screen anyway.

It’s an advertiser’s dream - millions of teenage consumers glued to screens through which retailers can throw messages. And there’s another big plus - with interactive technology, there’s nothing standing between the child and the purchasing decision. Let the cybertills roll.

The researchers’ first worries are about the lack of social interaction implied by this trend. I think that’s overstated. What the survey does not mention is the number of teenagers who also have telephone extensions or even their own numbers in their bedrooms. Alongside their viewing of EastEnders or “Corrie” they’re on the phone yakking to their mates.

I am also less than convinced that the screen technology means they won’t learn to read. Most computer interfaces are still text-based; the time to worry will be when we go over to voice-activated technology.

Even TV still demands some capacity to read text. In our house, Who Wants To Be A Millionaire? is known as the ultimate feel-good programme, since you know you must be smarter than the contestants, especially those who can’t work out whether a teaspoon is bigger or smaller than a tablespoon. Even here, however, the viewer is asked to read the captions, with helpful voice-over by Chris Tarrant.

For boys particularly, the TV football has led to an explosion in football magazines and semi-professional fanzines, which they read avidly.

The alarm signals in this survey lie elsewhere. First look at what the children are watching - principally soaps, movies and game shows. A generation which is not watching quality drama won’t ever want to make the leap into literature. The cinema is making a concerted assault on the classics - Emma, Shakespeare in Love, for example - but TV is making the colour of drama bolder, cruder and less sophisticated. There is strong contemporary drama available, and some of it is brilliantly original, but increasingly, it is the American offerings which dominate children’s viewing. That is a serious cultural threat for the future.

Worse still, it means that we are raising a generation which does not handle ideas well. TV is excellent at telling stories, where one event follows another in a linear narrative. It cannot easily cope with a complex interplay of arguments; that is still the province of print, or sometimes radio. In a complex world, we may be robbing our children of vital intellectual skills.

The second danger the survey reveals is parents’ virtual abandonment of their role as setters of limits in the home. The children were clear that though their parents told them to turn off the TV at a certain hour, the ban was both unenforced and unenforceable. Parents were relieved that their children were safe at home; whatever misgivings they had about excessive TV viewing or Internet-surfing were swamped by relief that they weren’t out buying drugs or being molested on the streets.

The balance of power in the home is changing; our desire to keep our children safe may mean that we are unwittingly allowing them to set their own agendas too early. The danger is not that our children will turn into couch potatoes; it is that they are increasingly being left to raise themselves.

Trevor Phillips is a journalist and broadcaster and a candidate to be Mayor of London