Recent studies prove that sleep deprivation impedes the growth of children and young adults. “Many of a child’s growth hormones are released in their sleep,” says endocrinologist Sharika Aamer, “so insufficient sleep can limit their growth.” In this manner, sleep deprivation can chop up to four inches off of one’s total expected growth. According to sociologist Paul Shirley, as young adults are increasingly pressed for their time, a decline in height might be expected through the generations.