The happiness index of people in Jiangsu, Sichuan, Fujian provinces and Chongqing municipality was found to be high, with half of families saying they were satisfied with family life, while people living in big cities like Beijing, Shanghai and Shenzhen were not so lucky.

According to a survey conducted in 10 Chinese cities on the happiness of middle income families with annual incomes of more than 50,000 yuan ($7,325), the happiness index in smaller cities was much higher than in big cities.

In terms of income, the survey showed families with annual incomes of between 11,000 and 20,000 yuan were happiest. People aged between 30 and 35 were happiest, according to the survey.

The pinch of high housing prices, fierce office competition, traffic congestion and high cost of kids' education were the main causes of the low happiness index in big cities like Shenzhen, the Guangzhou Daily reported Wednesday.