Let Them Sleep: Why School Should Start Later

Here’s a contrarian thought for every parent and teacher who has ever nagged a teenager to “just go to bed earlier”: the problem is not their willpower. It’s their biology. And our school schedules are fighting against it.

We tell teens to study harder, get better grades, and stay out of trouble, yet we start the school day before their brains are even awake. The American Academy of Sleep Medicine recommends that teenagers 13 to 18 years old sleep 8 to 10 hours per 24 hours for optimal health (AASM Consensus: Recommended Sleep for Teens, 2016). But in 2023, only 23% of U.S. high school students got at least 8 hours of sleep on an average school night, down from 32% in 2013 (CDC Youth Risk Behavior Survey, 2013-2023). That’s a disaster, and we’re the ones causing it.

The Biology of the Teenage Brain

Adolescence is a unique developmental window. The National Institute of Mental Health explains that the brain finishes developing in the mid-to-late 20s, and the prefrontal cortex—the part responsible for planning, prioritizing, and making good decisions—is one of the last to mature (NIMH The Teen Brain: 7 Things to Know). Meanwhile, the sleep hormone melatonin stays high later at night and drops later in the morning during adolescence (NIMH The Teen Brain: 7 Things to Know). In other words, teens are biologically wired to stay up late and sleep in. Forcing them to be at a desk by 7:30 AM is like asking an owl to sing like a lark.

The result? Sleep-deprived teens face attention, behavior, and learning problems, plus increased risks of accidents, injuries, hypertension, obesity, diabetes, and depression (AASM Consensus: Recommended Sleep for Teens, 2016). The CDC adds that insufficient sleep in teens is linked to being overweight, engaging in unhealthy risk behaviors like drinking and smoking, and performing poorly in school (CDC School Start Times MMWR, 2011-12). We’re literally sabotaging the very outcomes we claim to care about.

The Case for Later Start Times

So what’s the fix? The American Academy of Pediatrics has urged that middle and high schools aim for a starting time of no earlier than 8:30 a.m. (CDC School Start Times MMWR, 2011-12). Yet in the 2011-12 school year, the average U.S. public school start time was 8:03 a.m., and only 17.7% of schools started at 8:30 a.m. or later (CDC School Start Times MMWR, 2011-12). That’s a clear gap between evidence and practice.

Later start times align school schedules with adolescent biology. They allow teens to get the recommended 8-10 hours of sleep, which improves attention, learning, and mental health. The CDC’s 2023 analysis found that protective factors, including school- and community-level ones, were associated with lower prevalence of mental health issues and suicide risk (CDC MMWR 2023 YRBS Mental Health & Suicide Risk). A later start time is a structural protective factor we can implement.

Addressing the Counterargument

Critics will say: “Teens will just stay up later if school starts later.” But the evidence suggests otherwise. A Norwegian study of over 8,000 adolescents found that more than 3 hours of social media or gaming per day was linked to higher odds of sleeping less than 8 hours on weekdays (Norwegian school study, 2024). That’s a screen-time problem, not a start-time problem. However, even if some teens stay up later, a later start time gives them the opportunity to still get enough sleep. And the current schedule doesn’t guarantee early bedtimes—it just guarantees early wake-ups. The counterargument assumes teens will always fight sleep, but biology says they can’t fall asleep early even if they try.

Moreover, the benefits of later start times extend beyond academics. Motor vehicle crashes are the leading cause of death for U.S. teens (CDC Teen Drivers, 2024), and drowsy driving is a known risk. Teens who get more sleep are less likely to crash. The WHO reports that road traffic injuries are the leading cause of death for people aged 5-29 worldwide (WHO Road Traffic Injuries Fact Sheet). If a later start time saves even a few lives, it’s worth it.

What We Can Do Today

We can’t wait for every school district to change its schedule overnight. But we can push for change at the local level. Parents, teachers, and students should advocate for later start times, citing the AAP recommendation and the data. In the meantime, we can also tackle screen time. The same Norwegian study found that more than 3 hours of social media after school was associated with 1.31 times higher odds of psychological distress (Norwegian school study, 2024). And the U.S. Surgeon General’s advisory reported that adolescents who spend more than 3 hours a day on social media face double the risk of poor mental health outcomes (U.S. Surgeon General Social Media & Youth Mental Health Advisory, 2023).

So here’s my specific recommendation: push for a later start time, and simultaneously help teens set boundaries around screens. For example, if your teen is sleeping only 6 hours a night, that’s 2-4 hours short of the recommended 8-10. Moving the start time from 7:30 to 8:30 could add an hour of sleep, making a real difference. And if they’re scrolling TikTok until midnight, help them charge their phone outside the bedroom. The data shows that reducing screen time can improve sleep and reduce distress.

Conclusion

We have a choice. We can keep blaming teens for being “lazy” and “disrespectful” when they can’t stay awake in class, or we can align our systems with their biology. The evidence is clear: later school start times improve sleep, health, and academic performance. It’s time to stop fighting biology and start making common-sense changes. Our teens deserve better.

Sources

• CDC Youth Risk Behavior Survey (2013-2023) - https://www.cdc.gov/yrbs/dstr/dietary-physical-sleep-behaviors.html
• Norwegian school study (2024) - https://pmc.ncbi.nlm.nih.gov/articles/PMC11517197/
• CDC School Start Times MMWR (2011-12) - https://pubmed.ncbi.nlm.nih.gov/26247433/
• NIMH The Teen Brain: 7 Things to Know - https://www.nimh.nih.gov/health/publications/the-teen-brain-7-things-to-know
• AASM Consensus: Recommended Sleep for Teens (2016) - https://pubmed.ncbi.nlm.nih.gov/27707447/
• U.S. Surgeon General Social Media & Youth Mental Health Advisory (2023) - https://www.hhs.gov/surgeongeneral/priorities/youth-mental-health/social-media/index.html