طول مدت خواب، نگرش مثبت نسبت به زندگی و پیشرفت تحصیلی: نقش خستگی در طول روز، تداوم رفتاری و زمان شروع مدرسه

Sleeping less than an average of 8 h per night was related to more tiredness, inferior behavioral persistence, less positive attitude toward life, and lower school grades, as compared to longer sleep duration. Daytime tiredness and behavioral persistence mediated the relationship between short sleep duration and positive attitude toward life and school grades. Students who started school 20 min later received reliably more sleep and reported less tiredness.