Every night’s sleep is different, and how you sleep on any given night is likely to be determined largely by short-term causes – what and when you ate, how much exercise you did today, stress levels, what you watched on TV, whether your partner is snoring – but there are also fundamental, long-term differences between people in their sleep patterns. It is thought these differences are often genetic, and recent research supports this idea, identifying for the first time a gene involved in determining how much sleep we need.
Sleep is a huge part of our lives, and the lives of many animals. Although we still do not fully understand the strange phenomenon that takes up a third of our lives, it is clear that without it we cannot survive. But with a growing number of things keeping us awake – work, tv, friends, sport, buzzfeed, reddit – how much sleep is enough sleep?