Education · Level 3 · Advanced
A one-hour delayed school start improves sleep, sleepiness and inhibitory control in early adolescents in a randomized controlled trial
Reynaud E, Malevergne L, Grellet A, et al. (2026). Scientific Reports. doi:10.1038/s41598-026-50892-6 · CC BY 4.0
Step 1 of 2Read the paper
Does starting school an hour later help young teenagers sleep more and think better? In a French boarding school, four classes of 12–14-year-olds were measured with wrist sleep trackers, a sleepiness questionnaire and attention tests; then two classes switched from 8 a.m. to 9 a.m. starts while two stayed the same, and everyone was tested again about six months later.
How to read it
- In Methods, find the primary outcome, how classes were allocated and why the boarding school setting was chosen.
- Fig. 1 (flow chart) shows how many students dropped out of each analysis and why.
- Tables 2 and 4 are the heart of the paper: read the "T1-T0" columns for each group, then the difference-in-differences.
- Read the last five paragraphs of the Discussion for strengths, limitations and generalisability.
Step 2 of 2Take the test
15 questions · about 50 minutes including reading · pick an answer to see straight away if it’s right. Nothing is saved.
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Paper: Reynaud E, Malevergne L, Grellet A, et al., Scientific Reports (2026), licensed CC BY 4.0. Summary and questions are Research Nest’s own; read the original for the full study.