Brits OK with sex at 16, alcohol at 18

London: Half of British parents think childhood ends at 11 years old, a survey said on Monday.

Almost three-quarters of British parents allow their children to drink alcohol before age 18 and nearly a half of them allow their 16 year-olds to spend a night at their respective partner's house, said the survey commissioned to launch the latest book by children's author Jacqueline Wilson.

The ICM survey of almost 1,200 parents with children aged under 18, commissioned by publisher Random House, found that more than half believe children are 'young adults' at 11.

The author of The Story of Tracy Beaker — about a 10-year-old growing up in a children's home — said she thinks young people are growing up too quickly.

"I feel it is a real shame that children act like adults at an alarmingly early age," Wilson told Britain's Times newspaper.

The survey was commissioned by to help launch Wilson's latest book: My Sister Jodie.

"Because the narrators in my novels are teenagers, it may look as though I am pushing for teenagers to have more freedom," Wilson said. "But it is not what I believe."

Fifty-three percent of teenagers under 16 are allowed to stay out later than 11 pm while more than two-thirds of pre-teen girls are allowed to get their ears pierced, the survey showed.

Wilson urged parents to be stubborn in not giving in to their children's unreasonable demands. "Parents need to take a stand, to tell their children 'I don't care if everyone else in the class is allowed to do this or that. You're not,'" she said.

"No one wants a confrontation, but adolescence is a tricky time and it is the nature of the beast that teenagers are a bit stroppy. You just have to accept that."