Ask any parent and they’ll tell you that bedtime can be one of the most fraught and stressful times of the day. No matter how tired their bodies may be, kids resist the idea of going to sleep at their prescribed bedtime, as though they are afraid that they will miss out on something important. But a new study that is a result of a collaboration between researchers at McGill University and the Douglas Mental Health University Institute in Montreal has provided a whole new justification for parents to provide to their children: the more quality sleep that they get, the better their grades are likely to be in their math and language classes.
The scientists discovered that there is a distinct association between a student’s performance on tests and their sleep efficiency scores – sleep efficiency is a measure of how well you sleep at night. According to clinical psychologist Reut Gruber, the lead author of the study, “Sleep efficiency is the proportion of the amount of time you slept to the amount of time you were in bed. Simply put, you go to bed, you lie down and spend time in bed, but if you’re not able to sleep through the time in bed, that’s not efficient sleep. Short or poor sleep is a significant risk factor for poor academic performance that is frequently ignored.”
Gruber goes on to explain that though there are plenty of published studies that confirm a link between sleep and grades, she set out to find the answer to a slightly different question. “I wanted to look at specific subject areas, not to lump them together, knowing that different skills are needed for different subjects.”
It has been well established that different parts of the brain are used for different types of problem solving. “For math and languages,” Gruber says, “we need to use the skills that are called ‘executive functions’ — things like working memory, planning, not being distracted. The hardware that supports those skills is in the pre-frontal cortex of the brain, which is very sensitive to the effects of poor sleep or insufficient sleep.” In order to determine how sleep impacts performance on different types of academic performance, her team studied 75 students between the ages of seven and eleven. Each of the children was outfitted with an “actigraph,” a device that looks like a wristwatch that measures nighttime activity in order to gauge sleep quality. The data was gathered over a period of five nights, and then compared to the grades that the students had earned.
By adjusting the data to account for the various existing factors that could also be associated with grades (such as socio economic status of the children’s families and the children’s ages), the researchers were able to use the data in a way that showed that the quality of sleep that a child got provided an accurate predictor for how they would perform on academic tests. Gruber says, “Math, English, French, each one separately. Then we looked at how much variability in the specific grade or subject was explained by the sleep variables after controlling for the other what we call ‘confounders.’” The results showed that there was a particularly significant performance association between a good night’s sleep and scores in math and language classes, with the greater association being linked to mathematics. “We found that fourteen percent of the variability we found in math was explained by sleep deficiency,” Gruber said. “It was seven percent and eight percent for English and French.”
There is no doubt that when it comes to enforcing bed times, the chief responsibility lies with a child’s parents, but Gruber hopes that pediatricians are paying attention to the results of studies like hers and taking the time to ask about how a child is sleeping when parents bring them in for well check-ups. “I think many kids might have some sleep issues that nobody is aware of. Regular screening for possible sleep issues is particularly important for students who exhibit difficulties in math, languages or reading.”
There is no doubt that her conclusions are supported by the National Sleep Foundation. The organization has indicated that kids between the ages of five and twelve should be getting a minimum of ten to eleven hours of sleep each night. They also recommend that teens get a minimum of nine hours, and the fact that only about fifteen percent of the countries adolescents are achieving this sleep quantity has served as a catalyst for recommendations by pediatric organizations to move back school start times. If you are a parent, it is advised that you take a more tactical view of your child’s sleep schedule — many parents treat bedtime loosely, believing that if they’ve sent their child to bed and they are relaxing in their room, it counts as rest. Gruber’s study provides a clear indication that there is a difference between time spent in bed and time spent sleeping, and that can have a dramatic impact on academic performance.
To assess exactly how much sleep your child is getting, it is suggested that parents start to keep a log of what time they go to bed, as well as when they actually turn off the lights and go to sleep. If it turns out that your child is not getting the amount of sleep that is recommended for their age the it is recommended that a change is made. This may mean removing televisions and other electronic devices from bedrooms and enforcing a lights out policy, or even moving bedtime earlier into the night. Though your child may object to these new rules, they will likely result in better grades, and may also have the added benefit of a child whose mood is much improved by the fact that they are getting the amount of rest that they need.