Sleeping cycles

Without the Moon, Earth would be very different indeed. It keeps the planet’s orbit stable, preventing Earth from tilting too far and thereby ensuring a life-sustaining climate. It’s responsible for the tides, gravitationally pulling the oceans towards it, causing Earth’s waters to rise and fall. And it triggers terrible transformations in creatures called werewolves – unfortunate individuals cursed to turn into savage beasts at every full moon.

Ok, so the last one isn’t true. Rather, it’s one of many superstitions and tales from around the world in which the phases of the Moon are said to influence human behaviour. Less extreme versions of ‘the lunar effect’ include the misconception that crime rates increase when the Moon is full, or that mental illness is more pronounced at certain points in the lunar month. There are traces of this belief in the English language, with the word ‘lunatic’ literally meaning ‘moonstruck’. But while widespread in folklore, there is little scientific evidence for a lunar influence of this kind. The Moon is simply too far away to cause any significant changes in human behaviour from one part of the month to the next.

However, new evidence suggests the Moon may affect us physically. An extensive study of 33 volunteers by researchers at the University of Basel in Switzerland has discovered that during a full moon, volunteers slept for less time and took longer to fall asleep. This suggests that the Moon has some influence over human sleep patterns – the question now is: how?

One obvious answer is that the Moon is at its brightest when full, so perhaps the extra moonlight disturbed the participants’ sleep. However, the tests were performed in a darkened room, away from any glare, suggesting a more complex link. Another possibility is that our internal body clocks are in some way synchronised with the phases of the Moon, just as marine creatures like the grunion fish match their breeding habits to the lunar cycle. But this still leaves experts with the task of uncovering why we would have evolved such a synchronisation – a tricky question sure to cause many sleepless nights!