In the mid 1990s, a school in Edina, Minn., did something unprecedented.
The school board changed the school’s start time to accommodate the sleeping habits of its adolescent students. They pushed the beginning of the school day back 65 minutes, from 7:25 a.m. to 8:30 a.m.
The idea was met with a slew of doubt and complaints. Some parents believed the later start would dampen participation in after-school activities. Other parents felt that their teenagers would simply stay up later than they already did. However, the school board stood by their plan and implemented it for an entire school year.
Effects of the Schedule Change
- The school’s drop-out rate diminished.
- Fewer students reported symptoms of depression.
- The number of fights at school dropped.
- Participation in after-school activities did not suffer.
- Average SAT scores for the top 10 percent rose dramatically.
Sleep Habits Are Rooted in Biology
Edina is a wealthy, mostly white suburban school. Would the positive effects of starting classes later follow suit in primarily low-income, minority student populations? Schools in Minneapolis that pushed back their starting times discovered the answer to be “yes.” The Minneapolis students’ grades improved, first period classes were attended more regularly and the student dropout rate fell.
The reason starting school later is privilege-blind, say researchers, is that our sleep habits are not the effect of culture but are rooted in human biology.
The lack of sleep affects the teenage brain in similar ways to the adult brain, only more so. Chronic sleep deprivation in adolescents diminishes the brain’s ability to learn new information, and can lead to emotional issues like depression and aggression. Researchers now see sleep problems as a cause, and not a side effect, of teenage depression. ~ David K. Randall
Adolescent Sleep Biology
Sleep researchers have discovered that when we enter puberty, the circadian (daily) rhythm of our body shifts back three hours. So our teenage body does not release melatonin, the hormone that makes us sleepy, until about 11 p.m. each night. This makes falling asleep before then basically impossible. It also means that adolescents still have melatonin in their bloodstream until about 8 a.m. each morning. They are not capable of being alert and ready to learn before that time.
The Circle of Life and Sleep Rhythms
As we mature into adulthood, our circadian rhythms shift again. Our body produces melatonin earlier in the evening, and it is out of our system closer to when the sun rises. Eventually, we may marry and have children who grow into teenagers. They will likely stay up late each night and want to sleep-in the next morning, as we did. We shag their sleepy selves out of bed and send them off to school, but if our schools are wise, not much before 8 a.m.
Whatever our age, the human brain does not function well unless it spends adequate time resting on a pillow, and the pillow time needs to mesh with our daily biological rhythms. Good mental health depends on it.
Source: Randall, David K., Dreamland: Adventures in the Strange Science of Sleep, Norton, 2012.
