New research shows that young children in Asian countries sleep less on average than children who live in the United States, Canada and New Zealand.

The study of parents of 28,287 infants and toddlers in 17 countries found vast cultural differences in bedtimes, total sleep and parents' perceptions of sleep problems among their children. Overall, children from Asian countries had the latest bedtimes—with children in Hong Kong bedding down as late as 10:30 p.m.—and the shortest total sleep times.

Parents in Asian countries tuck children in around 9:30 p.m. on average, while 8:30 p.m. is the U.S. average, and children in New Zealand go to sleep at 7:30 p.m., says Saint Joseph's University psychologist Jodi Mindell, PhD, who conducted the study.

She also found that 52 percent of the Asian respondents said they believed their children have a sleep problem compared with 26 percent of parents from the predominantly Caucasian countries.

The data raise important questions for sleep researchers about how much sleep children need, says Mindell. "We don't really know the true ideal," she says.

Meanwhile, the high numbers of parents who worry about sleep problems may indicate that pediatric sleep isn't getting the attention it deserves, she says.

"Children spend about 50 percent of their lives sleeping," she says. "Health-care professionals need to ask about nighttime because it's often a window into problems happening during the day."

—J. Chamberlin