Should a daytime nap remain part of our kids' school curriculum long after they've graduated from preschool?
According to a new study, the answer could well be yes - children who took regular naps performed better at school, had fewer behavioural problems and were happier well into adolescence.
The research, published in the journal SLEEP, looked at the midday napping habits of a group of almost 3000 children in china, for whom a lunchtime snooze is a regular part of life.
During the study, information about weekly nap frequency and average duration were collected when the kids were in grades four - six. When they reached the end of primary school, students underwent further testing including academic performance, self-reported positive psychology measures (grit, self-control and happiness) and IQ tests. Researchers also took into account factors such as sex, school grade, location of school, parental education and what time kids went to bed each night.
And the findings were clear.
"Results indicate benefits of regular napping across a wide range of adolescent outcomes, including better cognition, better psychological wellness, and reduced emotional/behavioral problems," the authors write. More specifically, kids who had daytime naps had higher self-control, grit and happiness as well as higher verbal IQs and better academic achievement.
In fact, the association with academic performance was particularly strong.
"Children who napped three or more times per week benefit from a 7.6 per cent increase in academic performance in Grade 6," says co-author and neurocriminologist Adrian Raine. "How many kids at school would not want their scores to go up by 7.6 points out of 100?"
The study brings the benefits of naps out of the lab and into the real world.
"Many lab studies across all ages have demonstrated that naps can show the same magnitude of improvement as a full night of sleep on discrete cognitive tasks," says sleep researcher Sara Mednick. "Here, we had the chance to ask real-world, adolescent school children questions across a wide range of behavioral, academic, social, and physiological measures."
The best part is - in theory at least - it's an easy change to make.
"The midday nap is easily implemented, and it costs nothing," says lead author Jianghong Liu. "Not only will this help the kids, but it also takes away time for screen use, which is related to a lot of mixed outcomes."