Reported by Kashmira Gander at The Independent: Teenagers may not be irritable because of supposed attitude problems, but because early school hours affect their biological clocks, scientists claim. New research shows that early starts can affect mood, and changing when the school day begins can perk up our teens, benefit their health and enhance their ability to learn.

The team leading the study published in the journal ‘Learning, Media and Technology’ suggest that “our ability to function optimally [and learn], varies with biological time rather than conventional social times”. Our sleep-wake cycle, or circadian rhythm, is the result of a complex balance between states of alertness and sleepiness regulated by a part of the brain called Suprachiasmatic Nucleus (SNC).

When a child’s biological time and school hours are closely aligned, like at the beginning of their school careers, their faculties are not affected. But during adolescence, the consequences become drastically clear, when “‘the conflict between social and biological time is greater than at any point in our lives” according to the academics. This is because during puberty, shifts in a teen’s body clock push the optimal time for sleep later into the evening, making it difficult for most teenagers to fall asleep before 11.00pm. When early schools starts are coupled with a teen’s biological clock, the result is chronic sleep-deprivation, and low grades and health problems.

Academics added that there is there is a body of evidence showing the benefits of synchronizing education times with teens’ body clocks. They conclude that while studies “consistently” show adolescents benefit from waking later, there is no evidence to show that early starts have a positive impact on how healthy or how academically successful school students are. Examples harnessing this body evidence include the United States Air Force Academy, where a later start policy saw the grades earned by a group of 18–19 year olds soar.