Many young adults in Shanghai, who were themselves only children when they were young, want to have a second child, a survey shows.

A survey released by the Shanghai Population and Family Planning Commission, showed that more than half the 4,800 respondents aged between 20 and 30 said that -- if the one-child policy was excluded from the picture -- they would want to have a second child.

"The increase in the number of children a couple wants to have has a lot to do with them being the only children in their families," said Xie Lingli, director of the commission.

Shanghai allows couples who are themselves both only children to apply for a second child.

"However, the policy is not fully operational," Xie said.

China's one-child policy, initiated in 1979, has helped reduce the country's population by over 300 million people and delayed the arrival of the 1.3-billion population mark by four years, officials say.

The survey shows that more than half the respondents plan to have their first child when they are aged 24 to 27 and more than 70 percent want to have their parents take care of their children.

It also finds that more than 40 percent regard having children as a must in life, 33 percent think children will make life more interesting, 10 percent want to see a new generation and 8 percent believe that children ensure family stability.