Some people function well with fewer than 6 hours of sleep per night, while others need 9 hours or more. such differences in individual sleep patterns suggests that

Genetics are a very important factor in how people sleep, Each person's genetic make up is very different and that makes each person require different levels of sleep to function well each day. Some genetic makeups can function well on just a few hours of sleep while some require eight or more to make the body function properly each day.