One in five first-graders gets more than 10 hours sleep a day, according to a poll conducted by the Shanghai Education Commission.
In an equivalent study carried out last year, the proportion was less than one in 20, it said.
This year's survey was conducted in January and solicited the views of 155,000 children and their parents. The results were published yesterday.
The poll claimed that about 66 percent of first-graders sleep between nine and 10 hours a day. A year earlier the proportion was about 44 percent.
About 96 percent of parents said they don't help their children with homework. In 2015, the figure was 93 percent
About 90 percent of parents said teachers don't rank their children's test scores. In 2015 the figure was 71 percent.
About 95 percent of parents this year said their children had a "high interest in studying," up from 80 percent last year.
"This year's students appear more willing to communicate," said poll compiler Zhu Lei.
The number of parents who send their children to "cram schools" prior to them starting first grade was exactly the same this year as last, she said.
