Every year, I tell my students that sleep is just as important as revision and study habits when it comes to academic performance. And now, a compelling new study from the University of Cambridge and Fudan University gives us even more reason to double down on that message.
In a study involving over 3,000 teenagers, researchers discovered that those who:
- Went to bed earlier,
- Slept longer,
- And had lower sleeping heart rates,
scored significantly higher on a range of cognitive tests, including reading, vocabulary, and problem solving.
Even more striking? The actual difference in sleep duration between groups was minimal—just 15 minutes between the lowest and highest scoring groups—yet this small variation had a surprisingly large impact on brain performance and function.
Brain scans revealed that teens with the best sleep habits not only performed better but also had larger brain volumes and more efficient brain function.
Despite these findings, even the best-sleeping teens in the study didn’t reach the 8–10 hours per night recommended by the American Academy of Sleep Medicine. The healthiest group averaged just seven hours and 25 minutes of sleep.
Why? Teenagers face a biological shift toward later bedtimes during adolescence. Add in screen use, homework, social media, and caffeine—and you’ve got a generation of students consistently underslept.
We’re not powerless. In fact, this is where we shine. As Psychology teachers, we can…
1. Teach the Science of Sleep
Incorporate sleep research into your lessons on cognitive development, memory, and mental health. Use this new study to show how even small changes in sleep patterns make a real difference.
2. Debunk Myths
Help students understand that “catching up” on weekends (aka social jet lag) doesn’t undo the damage of sleep loss during the week. Emphasize consistency.
3. Promote Simple, Practical Changes
Share strategies backed by experts:
- Encourage regular exercise to improve sleep quality.
- Urge students to limit screens an hour before bedtime.
- Support healthy bedtime routines, such as winding down with a book, journaling, or light stretching.
4. Embed Sleep into Pastoral Care
Work with your school’s wellbeing or pastoral team to create sleep hygiene workshops, or add sleep content into personal and social education. Oxford’s Teensleep project is a great resource for ideas and activities.
5. Make Sleep “Cool”
Reframe sleep as a performance enhancer. Better memory. Sharper thinking. Bigger brains. It’s the one lifestyle change that benefits everything from academics to mental health—and it doesn’t cost a thing.
Professor Barbara Sahakian, who co-led the study, put it best: “It’s the sleep driving the better cognitive abilities… Small differences in sleep amounts accrue over time to make a big difference in outcomes.”
Let’s empower our students to make those small changes—because every extra minute of quality sleep could mean a stronger brain, clearer thinking, and greater wellbeing.
Tom Coster - Psychology 
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