Biddulph says young girls are in a 'catastrophic' state of crisis because of the 'toxic' influences of advertising, celebrity and pornography which pressurise them to grow up too quickly.
In his new book, Raising Girls, he writes: 'To understand our daughters, we have to realise that their childhood is not like ours. To put it bluntly, our 18 is their 14. Our 14 is their ten.
'Never before has girlhood been under such a sustained assault, ranging through everything from diet ads, alcohol marketing and fashion pressures, to the inroads of hard pornography into teenage bedrooms.'
He adds: 'About five years ago... we began to see a sudden and marked plunge in girls' mental health.
'Problems such as eating disorders and self-harm, which once had been extremely rare, were now happening in every classroom and every street. But more than this, the average girl was stressed and depressed in a way we hadn't seen before.'
However, he argues the 'enormous pain and confusion' that girls experience can be eased by increasing the number of women in their lives other than their mother who can act as mentors.
Biddulph said parents and relatives are not supporting girls in the way they did in the past. He added: 'We haven't put enough adult time and care around our daughters, or taught them well enough.'
Biddulph, who has a son and a daughter, said that parents must spend more time with their children and organise events to include other relatives.
He said that by widening the net of parental responsibility to include women relatives, girls would feel encouraged to share problems and confide in older people.
Biddulph said this is important because girls do not always get on well with their mothers and do not feel they can discuss certain subjects with them.
The idea of the 'aunties army' can be seen in the example of actress Julia Roberts who is devoted to her brother's daughter, up-and-coming actress Emma.
The 21-year-old, who bears a striking resemblance to her aunt, has been steadily carving out a career under her aunt's mentorship, starring in teen movies Wild Child and Nancy Drew, and appearing with her aunt in the 2010 romantic comedy Valentine's Day.
When Emma was a child, her aunt allowed her to spend weeks on set with her.
Biddulph's new book is due to be published later this month and follows the success of Raising Boys, which has sold 3million copies worldwide.
- Daily Mail