Parents should let their children enjoy growing up - with the associated risks - rather than being over-protective, a safety watchdog has argued.
Bumps, bruises and even broken limbs are an important part of growing up and children should not be discouraged from getting them.
The Royal Society for the Prevention of Accidents, based in Birmingham, said keeping children cooped up and away from danger was "detrimental" to their development. The organisation spoke out in the wake of a report last week highlighting how many parents are not allowing their children to go out on their own until the age of 14.
As a result, the Children's Society research claimed, youngsters are being denied the chance to develop vital peer-group friendships.
However, Peter Cornall, head of leisure safety at RoSPA, said: "Learning what hurts is an important skill to develop in childhood.
"There is nothing wrong with having scabs and bruises on your knees as a child. It shows you have been running around.
"If you fall out of a tree and you break your wrist, it is better to have that than to be at A&E with repetitive strain injury from using the computer too much."
Research for The Children's Society found 43 per cent of adults think children should not be allowed out with their friends until they are 14 or over.
Most, however, admitted they were allowed to play unsupervised from the age of ten or younger when they were children.
Mr Cornall criticised parents for attempting to wrap their children up in cotton wool.
"You can see why parents are so concerned because of the fears highlighted in the media, such as with Madeleine McCann," he said.
"But it is not right. It is detrimental to children's development. It also means when they get to 13 or 14 when they are allowed out, they more or less have an accident straight away because they suddenly have all this freedom."
RoSPA will be holding a conference at Loughborough University on Thursday to promote the benefits of outdoor play.
It will also aim to encourage councils and play providers to think more imaginatively about the type of park equipment they provide.
The Children's Society study found most parents (69 per cent) believed childhood friendships were very important. In the Midlands, nearly three-quarters of adults said they were still in touch with at least one childhood friend.
Children contacted for the organisation's Good Childhood Inquiry claimed they were more likely tell a friend if they had a problem, such as being bullied, than their parents.
But the research raised concern that friendships are changing, with evidence that since 1986 the number of teenagers with no best friends has increased from about one in eight to almost a fifth.
Andrew Gilyead, regional director of the Children's Society, said: "The survey shows parents are in a bit of a quandary.
"They have their own experience as a benchmark and value what that gave them but there is something about the modern world that makes them think it is not appropriate to apply that benchmark to their children now."
Birmingham's elected head of children and youth services Councillor Les Lawrence (Con, Northfield) encouraged parents to give youngsters more freedom.
"We have created a misguided view under this health and safety concept that anywhere a child goes should be totally safe," he said.
"That cannot ever be guaranteed, therefore children are not allowed to experiment and learn in the fuller sense of the word because we have created a perception that if a child hurts itself in a park, someone else is to blame."
Roy Wheway, a child safety expert who is a consultant for the Child Accident Prevention Trust, said cars, not parents, were to blame for fewer children playing outside. He said: "My research has shown is that where the car doesn't go the parents let them out as they used to."
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