'I'll be home at teatime...'

Remember those childhood adventures? That den in the woods, the secret tunnel by the old factory, the bike rides along the canal towpath?

Remember those childhood adventures? That den in the woods, the secret tunnel by the old factory, the bike rides along the canal towpath?

Chances are that if you were born 30 or more years ago, you will have some memories of the delights, and horrors, of playing in the great outdoors from dawn to dusk. But no such memories await today's children, it seems. According to the latest research, the pleasures of outdoor play are being denied to youngsters, whose childhoods are increasingly being spent inside watching TV and playing computer games.

A report from the Children's Society suggests that children are being prevented from playing outside by grumpy and intolerant adults, whose view is that children should be neither seen nor heard. Eight out of 10 children told researchers that they had been told off for playing outdoors, and half said they had been shouted at, with 11-year-olds attracting the most adult hostility.

But is it as simple as that? After all, adults in Britain have always been pretty intolerant of kids, especially other people's, and have tended to be more comfortable in the company of quiet, unquestioning, ever-grateful pets.

And there is little doubt that other factors are at play. There is pressure against outdoor play from parents, who are increasingly mindful of stranger-danger and child molesters, and who rest easier when their children are inside on the computer rather than playing with friends outside. Playgrounds, once a Mecca for children, are in decline, often because councils no longer want to risk claims for injuries incurred on slides and swings.

The decline of the extended family has had an effect too, with far-away grandparents no longer able to provide an alternative safe playing haven. And then, of course, there is the traffic, the sheer volume of which has restricted the movements of children and prevented them wandering far from home.

The result of all these societal changes is that children don't get out any more. And it is not only UK youngsters who are missing out on a life in the open air. A survey of new American graduates aged 21 to 24 found that many had parents who would not allow them to play outside because of fears they would be kidnapped or victims of molestation. Similar fears have been reported in Japan and South America.

The consequences of losing out on outdoor play can be long lasting: "When we play games with other children we learn how to compete, organize groups, be creative, and develop socially. It also helps to relate to others and to form relationships,'' says psychologist James Ryde.

Today's children are facing pressure from two directions. If they stay inside watching TV or playing on the PC, they risk being labelled as an obese couch potato, and if they do venture outside they risk incurring the disapproval of parents and the intolerance of neighbours.

According to the latest research, most are now opting to stay indoors, denied the opportunities to let off steam, and forced into a sedentary and unhealthy lifestyle that is likely to fuel the growing obesity epidemic. A survey of parents carried out by Powergen found that seven out of 10 children spend more time playing on computers and watching TV during the summer holidays than anything else, and one in four youngsters spend seven or more hours per day on such indoor activities.

According to the Children's Society research, which is based on the responses of 2,800 children, adult intolerance is a significant problem: "Playing outdoors is a fundamental part of everyone's childhood, but that is being threatened by a culture of intolerance towards children's play in public. We are in danger of letting grumpy adults tidy our children away,'' says the society's Tim Linehan.

"Children can only roam about half as far as they used to, and that is how parents respond to the towns and cities where we live. When I was a boy, if I was told off - and there has always been some tension between adults and children - we would always go off and play somewhere else. Now, children don't have as many choices as they used to.''

In one case of adult intolerance, according to the society's research, an eight-year-old girl in Somerset was stopped from cycling down her street because of complaints that the wheels of her bike squeaked. In another, a Liverpool boy was stopped from bouncing a ball against an unused garage because of potential damage to brickwork.

Other findings included the shelving of plans for a netball hoop on an Oxfordshire village green because of complaints that it would attract children, and the discovery of no less than 115 "no-ball-game" signs on one housing estate in Stockport.

"Too often a not-in-my-backyard attitude denies children the chance to have fun and meet with their friends, stifling their social development. Children want to get out and play. It's healthy and good for them,'' says Tim Gill, the director of the Children's Play Council.

As ever, identifying the problem is easier than finding a solution. The NSPCC has also looked at the issues and suggested a number of initiatives, including reintroducing park wardens to create safe spaces for children to play, as a way of encouraging children to go out and use open spaces. That was four years ago.

One-off projects for encouraging children to play outdoors abound, but fail to tackle the underlying problem, that adults now appear more intolerant of children than they have ever been.

Why that should be is not clear, but one theory gaining currency is that the intolerance has grown up because children are not seen as much as they once were. Taken to school by car, driven to leisure activities, and cocooned at home with a computer, they are no longer an everyday sight.

"One of the questions we need to ask is, 'Are we hiding our children away?' We drive them to school, for instance, so we don't see them on the streets. People are horrified if anyone says a child should take a bus to school,'' says Linehan. "We are all responsible for children's safety, but because children are seen less, we are not used to looking after other people's children and we become less tolerant. We have lost something."

The fear is that unless something is done, more and more children will end up as unhealthy, overweight young adults whose childhood memories will be of time spent alone in a bedroom with a computer rather than out with friends.