5 Myths About Shut-Eye You don't really need 8 hours, expert says By Neal Colgrass, Newser Staff Posted Nov 25, 2012 4:43 PM CST 10 comments Comments A woman wakes up, but did she get enough sleep? (Shutterstock) (Newser) – Still sleeping off those Thanksgiving leftovers? Then let's consider a few myths behind the science of sleep: At the Washington Post, sleep expert Till Roenneberg lists five: That eight-hour thing. There's no one perfect amount of sleep that's right for everyone. Only 27% of people sleep eight hours or more, according to Roenneberg's research. Adults over 30 average roughly 7 hours. Yet Roenneberg says that we sleep "about two hours less per night than 50 years ago," which is bad for our health. "Early to bed..." An early bedtime and early wake-up made sense before electricity, when our body clocks followed the sun. But now that we stay up later, it's actually better to sleep in. Most of us can't, of course, so we suffer from sleep deprivation and catch up on weekends. Workouts help us sleep. Exercise might help, but it's really daylight that helps you sleep by synchronizing your body clock to the sun. Partners have differing sleep habits. True, women tend to sleep earlier—but that's about genetics and biology rather than personal preference. One neat fact: Women control the sleep times of their husbands, making them sleep earlier than they would as bachelors, according to research. Click for Roenneberg's fifth sleep myth.