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The question still perplexes scientists, but there are now several intriguing theories that explain our need for a daily nap.
Some people need eight hours. Others can exist on four. But the bottom line is that everybody needs sleep - it is as essential as breathing and eating. Yet, despite decades of study, scientists still do not know why we do it.
However, there are some intriguing clues and theories. One obvious clue is that we all feel better after a good night’s sleep, and much worse if deprived of a decent night’s rest. In humans the need for sleep gets so strong after a few days that nothing will keep you awake – with reports of people falling asleep standing up, even whilst being kicked or having intolerably loud music played at them. Within days of having no sleep, people report confusion, forgetfulness and hallucinations. (In case you are wondering, the world record for going without sleep is eleven days.)
But saying that we sleep because we are tired is rather like saying we eat because we are hungry – it is why we sleep, but not necessarily why we need it.
