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Restful slumber – Latest in sleep research (01/2016)

Later start to the school day, more alert children

Text: Christoph Dieffenbacher

Children and adolescents have long known it: If school starts later in the morning, they feel more rested and fitter. Even a small shift in school hours makes a difference, as psychologists at the University of Basel have discovered. Their findings have had consequences.

If the school bell rings just 20 minutes later in the morning, this is enough to have an effect on young people’s sleep duration and on how fit they feel during the day, as the team of developmental psychologists working with Professor Sakari Lemola reported a good three years ago. They had surveyed more than 2,700 teenagers between the ages of 13 and 18 and came to the conclusion that school pupils whose classes begin at 8.00 am sleep about 15 minutes longer and are more alert during the day than those who already have to be in the classroom at 7.40 am.

It is a well-known fact that sleep habits change during adolescence. Children still tend to be early risers, but adolescents often have difficulty getting up in the morning and do not feel sleepy until late in the evening. While the phase in which they fall asleep shifts clearly into the night, their need for sleep remains unchanged: it is approximately 8.5 to 9.25 hours per night and therefore still similar to that of ten-year-olds. During their school life, many teenagers thus suffer from a sleep deficit that impairs their ability to concentrate and with it their performance at school and general wellbeing.

Comparison of different schools

The team of psychologists from the University of Basel had visited secondary schools in the Canton of Basel-Stadt and asked questions about sleep – such as “When do you go to bed? When do you get up? What is the situation during the week and what is it like at the weekend? How do you feel during the day?” In one of the six schools in the study, classes began 20 minutes later in the morning because block teaching was used there more frequently. It was thus possible for the researchers to make a direct comparison between the different school hours, and they obtained a statistically significant result.

The Basel study, the first of its kind in Europe, triggered a considerable response as researchers in the USA had already obtained similar results previously. Professor Lemola, who is in the meantime an assistant professor at the University of Warwick in Great Britain and adjunct senior researcher at the University of Basel, says today that he was initially surprised to discover that a fairly small shift in the start of the school day leads to a significant improvement. He had assumed that the few minutes’ delay would not be of any considerable importance.

Model sets a precedent

The researchers met together with representatives from the authorities, which has had tangible consequences: As of the 2015/2016 academic year, classes for grades 1 to 9 begin at 8.00 am in the whole Canton of Basel-Stadt. Meanwhile, this model is setting a precedent elsewhere, too. It is currently being discussed in the Cantons of Bern and Zürich, for instance, and also in Germany. Professor Lemola reports that he frequently receives inquiries on this topic from within Switzerland and abroad.

In order to reinforce the positive effects of sleeping later, further demands have already been made, for example for starting classes at 9.00 am. However, this would have adverse consequences not only on the breaks but also on the syllabus. Unless classes were rescheduled to go on into the evening – which would in turn not be very compatible with leisure activities such as sport and music lessons or with evening meals as a family. For Professor Lemola, though, starting the school day at 8.15 am and offsetting the shift by means of shorter breaks would be a “reasonable compromise”.

From early risers to late risers

The older children become, the more their rhythm shifts in the direction of sleeping longer in the morning. The fact that they turn into evening people and morning grouches during puberty is due, first of all, to the complex biological changes, says Professor Lemola. However, research is still being conducted into the precise mechanisms of this change in the sleep-wake rhythm. This shift in sleeping habits, which lasts until the age of about 20, is found not only in our culture but also in other cultures according to the researcher. As adults, human beings find their way back to their childhood rhythm and become morning people again.

A second factor at work here, according to Professor Lemola, is what specialists describe as sleep hygiene. This refers to the lifestyle habits and behaviors that influence sleep. Here, the psychologist stresses activities late in the evening with laptops, tablet computers and smartphones, which are clearly linked to shorter sleep duration and more frequent sleep problems. Another study also found that young people who sleep less and have more sleep-related problems are more likely to suffer from symptoms of depression and ADHS.

Sleep is therefore also a civilization issue: The psychologist describes studies that found that Brazilian children from villages that were not yet connected to the electricity network slept more than an hour longer than children from areas that were already supplied with electricity. This is understandable and is in line with the findings that people in Europe 100 years ago – in other words before the widespread supply of electricity to households – slept one hour longer on average than they do today.

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