„Many now sleep less than seven hours most nights. Sleep experts say that teens should get about nine hours of sleep a night; a teen who is getting less than seven hours a night is significantly sleep deprived. Fifty-seven percent more teens were sleep deprived in 2015 than in 1991. In just the four years from 2012 to 2015, 22 percent more teens failed to get seven hours of sleep. The increase is suspiciously timed, once again starting around when most teens got a smartphone. Two national surveys show that teens who spend three or more hours a day on electronic devices are 28 percent more likely to get less than seven hours of sleep than those who spend fewer than three hours, and teens who visit social-media sites every day are 19 percent more likely to be sleep deprived.“
Univ.-Prof. Dr. Jean M. Twenge, „Have Smartphones Destroyed a Generation?“. In: The Atlantic online vom September 2017