"The idea that suddenly at 18 you're an adult just doesn't quite ring true," says child psychologist Laverne Antrobus, who works at London's Tavistock Clinic.
"My experience of young people is that they still need quite a considerable amount of support and help beyond that age."
Child psychologists are being given a new directive which is that the age range they work with is increasing from 0-18 to 0-25.
http://www.bbc.co.uk/news/magazine-24173194
So from the news, at least partly it would seem that the barrier is raising medically, so should it be considered elsewhere?
The article also says that driving theory should be taught in school to a degree, which i find to be a good idea considering the sheer amount of accidents for new drivers.
My personal opinion is that since we live quite a bit longer than we did when 18 was considered "adult" quality, why only allow retirement to be long and largely pointless, when you can also increase the amount of time people may have with their childhood, which is constantly being attacked by external influence to grow up, when they really shouldn't.