1: The start time for more than 80 percent of public high schools in the United States is 8:15 a.m. or earlier.  In fact, nearly 50 percent of those start before 7:20 a.m.

“School buses for a 7:20 a.m. start time usually begin picking up kids at around 5:45 a.m.,” writes sleep expert Matthew Walker in Why We Sleep: Unlocking the Power of Sleep and Dreams.  “As a result, some children and teenagers must wake up at 5:30 a.m., 5:15 a.m., or even earlier, and do so five days out of every seven, for years on end.”

Matthew’s summation: This is lunacy.

“Keep in mind that 5:15 a.m. to a teenager is not the same as 5:15 a.m. to an adult,” he writes.  Because the circadian rhythm of teenagers shifts forward dramatically by one to three hours.

As adults, would we be able to “concentrate and learn anything after having forcefully been woken up at 3:15 a.m., day after day after day?” he asks.  “Would [we] be in a cheerful mood?  Would [we] find it easy to get along with your coworkers and conduct [ourselves] with grace, tolerance, respect, and a pleasant demeanor?”


2: There is growing scientific evidence showing the wisdom of later school start times.  “One longitudinal study tracked more than 5,000 Japanese schoolchildren and discovered that those individuals who were sleeping longer obtained better grades across the board,” Matthew writes.  

“Controlled sleep laboratory studies in smaller samples show that children with longer total sleep times develop superior IQ, with brighter children having consistently slept forty to fifty minutes more than those who went to develop a lower IQ,” he observes.

Dr. Ronald Wilson at the Louisville School of Medicine has assessed hundreds of twin pairs from a very young age.  The results are striking in cases where one twin routinely gets less sleep than the other.  “By ten years of age, the twin with the longer sleep pattern was superior in their intellectual and educational abilities, with higher scores on standardized tests of reading and comprehension, and a more expansive vocabulary than the twin who was obtaining less sleep,” notes Matthew.

Some school districts are beginning to experiment with later start times.  In Edina, Minnesota, school start times were moved from 7:25 a.m. to 8:30 a.m.  The change in academic performance was dramatic.  Average verbal SAT scores for top-performing students increased from 605 to 761. Math SAT scores also improved for this group, from an average of 683 the year prior to the time change to 739 the year after.

“Numerous counties in several US states have shifted the start of schools to a later hour and their students experienced significantly higher grade point averages,” Matthew notes, with “the most dramatic surges occurred in morning classes.”

3: But that isn’t the only benefit of moving the start time back.  The life expectancy of students also increased, a benefit researchers did not anticipate.

“The leading cause of death among teenagers is road traffic accidents,” Matthew writes.  “When the Mahtomedi School District of Minnesota pushed their school start time from 7:30 to 8:00 a.m., there was a 60 percent reduction in traffic accidents in drivers sixteen to eighteen years of age.

“Teton County in Wyoming enacted an even more dramatic change in school start time, shifting from a 7:35 a.m. bell to a far more biologically reasonable one of 8:55 a.m.  The result was astonishing—a 70 percent reduction in traffic accidents in sixteen- to eighteen-year-old drivers.”

As a point of comparison: it was deemed a “revolution” when anti-lock brake technology—which allows drivers to maneuver their vehicles after braking hard—decreased accident rates by around 20-25%.  The data suggests moving school start times back will drop teenager accident rates by twice that.  

“These publicly available findings should have swept the education system in an uncompromising revision of school start times,” Matthew observes.  “Instead, they have largely been swept under the rug.  Despite public appeals from the American Academy of Pediatrics and the Centers for Disease Control and Prevention, change has been slow and hard-fought.  It is not enough.”

More tomorrow.


Reflection: What are the start times for schools where I live?

Action: Share this information with a principal or school board member.

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