Adult life begins at 40 for the Peter Pan generation

If you thought childhood ended when you left school, graduated or got a job, think again – for experts say some of us don’t stand on our own two feet until we’re 40.

That’s how long we allow ourselves to be carefree, according to Dr Brenna Hassett, an anthropologist at University College London.

Adulthood comes, she told Cheltenham Science festival, when people stop ‘investing’ resources in themselves and invest in other people, such as by becoming parents, with the financial and caring responsibilities that it requires.

Long childhoods might have developed to help us compete with Neanderthals, as the more time young Homo sapiens spent with adults, the more time they had to learn how to survive. But

‘It’s like we live for 300 years’

nowadays, many adults still rely on their parents or live at home until they’re 40.

Dr Hassett said: ‘We are lengthening our childhood like we are a species that lives 300 years. If you compare us to other species that have an equally long childhood, you get a whale.

‘Chimps spend one or two years in adolescence. They might reach sexual maturity and then have babies a couple of years later, when they’re socially ready. These are the most socially complicated animals we know. They take one or two years about it, and we are like ten, 20 even 30 years.’

She also discussed the ‘grandmother hypothesis’ in which women go through the menopause to help bring up their grandchildren, investing time and resources after they stop having kids of their own. Whales do something similar, she said.

In her book Growing Up Human: The Evolution of Childhood, Dr Hassett says her childhood effectively ended when she had her first child, aged 39.