Chronotype & Sleep Patterns
- By Steve Plantz
- Mar 1, 2016
In November, the Seattle school board voted to move school start times an hour later, to 8:45 a.m., for all high schools and most middle schools, beginning with the fall semester of 2016. Seventy of the nation’s more than 24,000 school districts have made similar changes in hopes it will allow students to perform better.
“We’re going to look back on this time period and wonder why it took so long,” said Phyllis Payne of Start School Later, a group that advocates for later school start times.
Research shows later start times help combat sleep deprivation and improve academic performance in teens. A University of Kentucky study found that early start times for elementary school students could result in poorer attendance and lower standardized test scores. The American Academy of Pediatrics and the Centers for Disease Control concur.
For years, educators and parents likely thought their kids’ poor school performances were due to the kids staying up too late. While that may be, research indicates it’s not necessarily the kids’ fault. It may be due to their chronotypes.
Their what?
Every human is born with distinct, inherited circadian rhythms that dictate when we like to wake and go to bed. One’s chronotype is the physical manifestation of one’s personal circadian rhythms. Some of us are early risers, who perform best in the early hours of the day. Such folks are considered A chronotypes. Those who like to stay up and wake up later, and, hence, perform better in the afternoon or at night, are B chronotypes. And 80 percent of 10- to 20-year-olds are B chronotypes, according to the b-society, a Danish organization that advocates for societal changes to accommodate people who perform better later in the day.
While a person cannot change their inherited chronotype, chronotypes can, and do, change over a person’s lifetime. Such changes are pronounced in adolescents and teens, producing morning fatigue and afternoon and nighttime energy, making it harder to fall asleep.
Oh, I’m a “slight Early type,” according to the analysis. Who knew?
