But Hao Maishou, a retired sociology professor and best-selling author, is leading a one-man campaign against 2,000 years of Chinese tradition by demanding an end to filial piety.

Although he appears to be cutting off his nose to spite his face, he says the culture of filial obedience and dependence is crippling China's sense of self-reliance and damaging its economic development.

According to Mr Hao, the Confucian tradition by which parents help their children establish themselves, and then are helped in turn as they get old, is morally wrong. "Actually, in our agricultural society, the social structure meant people taking from their children: take, take, take," he said.

His book, Father and Son: a Contract, has been a major talking point since it was published in December. It described how he made himself a test case for his theory.

Ten years ago, when his son left school, Mr Hao presented him with a contract. The son would have to pay his way through college, find himself a job, and buy his own flat when he got married.

In return, his parents promised to take care of their own pension and medical bills as they got old.

Such ideas are revolutionary in China. At the heart of Confucian morality is the saying that "filial piety is the root of all obedience".

In China, care for the elderly is a moral, and in some cases a legal, obligation for children, all the heavier in the age of the one-child policy.

There are an estimated 143 million people in China over the age of 60, or one in 10 of the population. According to a recent projection, that could rise to 430 million, or three in 10, by 2051.

In China's cities, rising house prices mean the young rely heavily on the extended family to get a foot on the property ladder.

They also use all-important "family connections" to get a job.

Mr Hao's son, Hao Ding, 30, had certainly seen things that way. "At first, he didn't think it was for real," said Mr Hao. "When he realised I was serious he was very angry. He put on a long face and there was something of a cold war between us for about six months.

"I think we have both benefited. When he was young he was an introverted kid. Now he's more confident and independent."

Nevertheless, Mr Hao has come under fire for his unorthodox views.

"Contracts can't solve the problems of real life," said a commentary in the Southern Daily. "In our socialist country, helping others, the value put on personal relationships, education for children and care for the elderly are symbols of a prosperous, civilised society. That's why China has so many families with several generations living together, and what the elderly in the West most envy about China."

On the other hand, Mr Hao has parents turning up at the door asking him to draw up similar contracts for them.

His son said the contract had been tough at first. His girlfriend left him after her parents learned of it and said she could not possibly marry into such a family. But he agreed he was now more independent-minded than his peers.

Would he impose such a contract on his own child, though? "I just couldn't," he said. "What if it doesn't work? You'd just be plunging the family into a social abyss."