A survey of parents in Britain sugests childhood ends for many youngsters by the age of 12.
Around seven in 10 parents said their children stopped being childlike by the age of 12.
Around a third said childhood lasted only until the age of 10, according to the Netmums poll, which questioned 1032 parents.
Around two thirds of parents said modern children grew up far faster than they did and only 2.5% said they thought it was harder when they were growing up.
The poll suggests childhood is under threat due to outside factors such as the internet, celebrity culture and images of thin or overtly sexy celebrities.
Other concerns are magazines aimed at young teens, but containing content more suitable for older teenagers, and the easy availability of suggestive images and online pornography.
Almost two thirds of parents cited peer pressure as one of the main factors making children grow up quickly.