Every parent knows the television shouldn't be used as a babysitting service, but most admit there are times they couldn't have done without it. Whether it's to keep a toddler entertained while you cook dinner or to placate an irritable teenager after a long day at school, nothing is more effective. And yet most parents can't kick the niggling feeling that TV is "bad" - but why?
"In the days of Sesame Street we trusted TV - it was a way of educating with entertainment," says Dr Brian Young, a media psychologist at the University of Exeter, UK. "Now we have a new media landscape and the boundaries between TV and genres, such as the internet, have become blurred. In addition, we have a wealth of choice."
Modern TV, according to numerous studies, leads to obesity and violence. It's been found in international research that children who consistently spend over four hours a day watching TV are more likely to be overweight. And children who watch violent behaviour are more likely to be aggressive and to fear that the world is a scary place.
The relationship between a child's age and their TV viewing - what and how much - is key. The first two years of life are considered a critical time for brain development. It's thought that TV can get in the way of exploring, playing and interacting with others. Most children under five, and often beyond this age, can't understand the difference between reality and fantasy, which can make TV a confusing experience. And as kids get older, too much TV can get in the way of them being physically active, reading, doing homework, playing with friends and spending time with family.
Too much TV could, then, leave you with a fat, violent, scared child, if these studies are correct - yet TV is consumed in nearly every home. According to the Kaiser Family Foundation (KFF) in the US, children aged six and under spend an average of two hours a day watching TV and using computers, while children aged 8-18 spend nearly four hours a day in front of a TV screen. Most of us have accepted that TV is part of our lives and rather than cut it out, like French fries, we hope that moderation might be the solution. But can anyone tell us how much is OK?
The American Academy of Pediatrics (APP) recommends that kids under two not watch any TV and that those older than two watch no more than one to two hours a day of quality programming. However, Young believes there is a problem with time limits. "The real issue is inertia. Research shows that the more TV you watch the more you get stuck to your seat. If a child is stuck on her own in front of the TV, she's less likely to get up and do something else. It's not about how long you watch for: it's the unbroken viewing that's the problem. It's better if a child multi-tasks while the TV is on, which they are excellent at doing from the age of six or seven, although of course TV should never become rolling wallpaper."
So perhaps the length of time kids watch TV is less relevant than the way in which they watch it. "It's easy to protect your children by watching TV with them," says Young. "Parents should act as the interpreter and buffer zone on what comes out of the box." Small children, for example, don't understand that commercials are designed to sell things; they need you to explain this to them. Older children might get sucked in by game shows, which suggest that success is a matter of luck and that hard work isn't necessary. These kinds of programmes, according to the experts, should be used as an opportunity for parents to talk about things such as greed and celebrity.
When faced with such research it's easy for anxious parents to think they should rush their flatscreen to the recycling centre. "I think this is a bit over the top," says Young. "Getting rid of your TV suits Luddite people who think all modern things should be banished, but their child might feel left out if everyone is talking about the latest episode of Glee at school and they can't join in."
Plus, no one can deny that some programmes are excellent at teaching young children their alphabet and numbers; older children can learn a lot from wildlife programmes, for example; and cultural customs can be learnt through clever programming too.
In these cases, even the experts concede that TV can work quite well as cheap and easy childcare. "Of course, children should not be plonked in front of the television for hours on end, but using it as an electronic babysitter for half an hour when there is a suitable programme on is fine," says the British child psychologist Dr Anne Sheppard. Which, quite frankly, is what we'd been hoping to hear all along.
So, now that niggling feeling has been addressed it seems we've been asking the wrong questions: the important thing is not how much TV your children should watch, rather it's what TV they're watching and how they're watching it.