Nearly 50 per cent of those questioned in a Barnardo's survey believe children are beginning to behave like animals, while more than two in five think they are "becoming feral".
The poll showed almost half of Britons think young people are angry, violent and abusive, with one in four thinking troubled children are beyond help by the age of 10.
Anne Marie Carrie, the chief executive of Barnardo's, said it was depressing that so many people were ready to give up on children.
The survey of more than 2,000 people found half thought children were beginning to behave like animals and more than two in five thought children were "becoming feral".
"What hope is there for childhood in the UK today if this is how adults think?" Ms Carrie said.
"We seem to have forgotten the fact that most children are well behaved and instead we are unquestionably accepting a stereotype of young people as criminal and revolting."
She went on: "We aren't asking people to put up with yobbish behaviour, but we do need to change our attitudes towards troubled children.
"It is a sad truth that those children who come across as angry and abusive have sadly often been scarred by their upbringing.
"But it's never too late to believe in children and change their life story, it doesn't have to end how it began."