Over the past few decades, sleep duration appears to have been declining for most people living in industrialized countries. But one group for whom this is particularly evident is teenagers . Nearly half of adolescents in the US report insufficient sleep, and suffer from daytime sleepiness on school days. One study of middle school and high-school students found that a whopping 80% slept fewer than 8 hours on school nights, and 33% of the students reported falling asleep in class. This is not as trivial as it may seem. Teenagers who don’t get enough sleep have poorer academic performance , are more likely to develop psychological problems like depression, are at higher risk of medical issues like obesity and diabetes, and are more likely to be involved in car accidents . The long term implications of insufficient sleep with respect to health, education, and achievement early in life should not be underestimated. So why is this such a pervasive problem? One factor that is