13 September 2023

School classes start too early. The problem affects most countries worldwide

School lessons should not start before 8:30 am, scientist warn. The circadian cycle of children, especially those over 10, is "delayed" by up to three hours compared to adults. Teenagers' brains at 8 am work much less efficiently and are unsuitable for learning. Furthermore, starting lessons before 8.30 a.m. affects students' mental health.

Author: Maria Mazurek,


Siora Photography/Unsplash

Depression, increased risk of traffic accidents, irritability, tendency to substance abuse, and learning problems. These are just some of the potential dangers of getting up too early (and getting too little sleep) by a student. Students need more than 9 hours of sleep each night. The research is alarming: most children and teenagers suffer from sleep deprivation. Educational activists and researchers on the development of children’s brains indicate that the cause is lessons starting too early.

The idea that children simply go to bed earlier (or at least try to) is not a solution. – It’s a matter of biology, not choice,” says Kyla Wahlstrom of Minnesota University, who was the first (back in 1996) to study the relationship between the start time of school and student’s health and academic performance. Children, especially those over the age of 10, have a different circadian cycle than adults, which is a direct result of their hormonal metabolism. Their brains are too active by 10:45 p.m. for them to fall into effective and healthy sleep.

Researchers who have devoted years of their work to studying the issue note that the most reasonable solution to prevent teenage sleep deprivation and its consequences is a later start to school lessons. These should not start earlier than 8:30 a.m.

Meanwhile, in most schools worldwide – from Singapore to California, from Arctic rim of Canada to equatorial Colombia, they start earlier. What’s particularly alarming, in some developing countries -where many children sometimes need to get up several hours earlier to get to a long-distance away school – classes start extremely early (in Uganda or the Philippines at 6:30 a.m.) Privileged instead are students from Finland, where lessons usually begin between 9 a.m. and 9:45 a.m.

Unexpected discovery

Until thirty years ago, no one questioned that lessons start before eight in the morning. The subject was completely unexplored, and teenagers’ annoyance at getting up was habitually explained by age-typical waywardness.

The change in the scientific world’s approach to students’ sleep-wake cycle – and notice of the problem in general – began in 1996 with the above-mentioned scientist (and former school teacher), Kyla Walhstrom. At the time, she was working at the Center for Applied Research and Educational Improvement at the University of Minnesota. As the researcher admits, when she started looking into this topic, she herself was skeptical about the impact of beginning lessons early. However, as her own research on a group of more than nine thousand students, some of whom had their lessons rescheduled to a later time (e.g., from 7:20 a.m. to 8:30 a.m.) later proved, such an arrangement resulted in a significant decrease in the number of reported symptoms of depression and addiction to caffeinated beverages. Furthermore, the students were found to be less likely to fall asleep in classes, and they behave less impulsively.

Their parents also noticed the change. Ninety-two percent of mothers and fathers admitted that their children “were easier to live with” since they got up a little later. Students’ educational performance has also improved. During the final exams, the children began to perform better in tests measuring both their language and math abilities.

Further evidence

The observations by Kyla Wahlstrom and her associates have been confirmed by a series of subsequent scientific studies. University of Rochester Medical Center studied 197 students aged 14-17. The conclusions left no doubt: those of them who started lessons later than 8:30 a.m. are in a better mental state.

The topic was also addressed by Paul Kelley, working at the Sleep and Circadian Neuroscience Institute at Oxford University. Studying British students, he calculated that British teenagers sleep 10 hours a week too little, which results in irritability, greater susceptibility to depression, and exhaustion. His estimates show that while elementary school students can start lessons at 8:30 a.m. without harm, classes for 16-year-olds should not start before 10 a.m. For 18-year-olds, the optimal time to start school falls even later: at 11 a.m.

In another medical study entitled “Homeostatic sleep regulation in adolescents,” Oskar Jenni, Peter Achermann, and Mary Carskadon demonstrate that sleep deprivation has a dramatically negative impact on adolescent functioning, resulting in depression, substance abuse and increased risk of car accidents, among other things.

Matthew Walker, professor of neuroscience and psychology at the University of California, Berkeley, and the author of a best-selling book entitled “Why we sleep?”, in turn points to psychological and behavioral aspects of sleep deprivation. These include a reduced ability to resist impulses and lower self-control, which can result in both emotional and social problems.


The undisputed issue remains the logistical difficulties that may be associated with starting lessons later. Parents planning their daily functioning based on the start time of their work may encounter difficulties getting their children to school later. Local education authorities would also have to make changes in the operation of schools. The Minnesota area was a pioneer in this regard, where research on the benefits of later lessons began. However, despite numerous pieces of evidence (including empirical ones) of the benefits of such an arrangement, very few educational policymakers worldwide have decided to introduce new regulations. Also due to anxiety about the parents’ and teachers’ reactions.

However, the question arises whether it is not worthwhile, given the highly positive effects that starting school later can bring, to consider modifying both regulations and daily routines.

As a Holistic Think Tank, we advocate for schools where the student will be the most important player and whose welfare is central. Our mission is based on the ten humanism-rooted values included in the “What School Ought to Teach” list. One of them is self-care, understood as a concern for the physical, mental, and emotional health, as well as developing an attitude of resilience to stress.

A sufficient amount of quality sleep is essential to achieve this purpose.