Later School Start Time Benefit Supported by More Evidence
A new study shows children sleep longer with later start time.
Posted Sep 17, 2013
While I have conducted no research directly related to school start times, my interview comments were about research on relations between sleep duration, sleep quality, and cognitive/academic performance. One year ago, I wrote in this blog on the topic of school start times.
In the piece I mentioned one study (Finley, 2012) that provides some of the strongest evidence for the benefits of starting school later.
Recently, other studies have been published on the topic. A group of Chinese researchers (Li et al., 2013) have just published results of a well-designed study with a very large sample. First, they conducted a survey of 20,778 children in 5th and 6th grades. Then they selected 818 children to follow for two years and discover if sleep was related to school performance. Finally, they conducted an intervention study with six school districts (553 children) to determine the effect of delaying school start time by 30 minutes or 60 minutes.
For the large survey, the results mirrored those of many U.S. and international studies. Short sleep duration defined as less than nine hours per night was found for 38% of children. Substantial daytime sleepiness was reported by 64% of the children. Children in urban areas showed less sleep and more sleepiness than those in rural areas. Higher family income and higher educational level of parents was related to shorter sleep duration. In the follow up study, children who had more daytime sleepiness had lower attention, learning motivation, and academic achievement. Moreover, children who slept fewer than 9 hours a night had poorer academic achievement.
The intervention study showed that delaying school start time had the effect of increasing sleep duration and decreasing daytime sleepiness. Further, there was a dose-related effect in that the one hour delay was more effective than the 30 minute delay. Children whose school start was an hour later went to bed at the same time as those in the control group (around 9:30pm), and got an average of around 30 minutes more sleep. These results run counter to the argument, raised by skeptics and opponents of delaying start times, that children would just stay up later if school began later, and their sleep would not be affected. Children with later start times also reported less frequent sleepiness.
While I support later school start times, I also caution that this action will not be a panacea for sleep deprivation and sleepiness that impairs student academic performance and increases behavior and emotional problems. I have written previously about the fact that school night activities are among the many reasons children do not get sufficient sleep (see my blog post from last year). Football season is here again, and my newspaper I read reports results of Thursday night games for 7th and 8th graders, and Monday night games for 9th graders. I’d be interested to hear from parents about similar schedules in their communities. Further, as many are quick to point out, it is the parents’ responsibility to see that children go to bed early enough to get sufficient sleep. I agree fully. But schools and communities can do more to create and support policies and practices that make it easier for them to do so.
Edwards, F. (2012). Early to rise? The effect of daily start times on academic performance. Economics of Education Review, 31, 970-983.
Li, S., Argulles, L., Chen, W., Jin, X. et al. (2013). Sleep, school performance, and a school-based intervention among school-aged children: A sleep series study in China. PLOS ONE, 8, e67928