Does The Moon Affect Human Behaviour?

Since starting out on my spiritual journey, I have become much more aware of the moon, her cycles and how it impacts upon my sleep pattern and moods. I frequently find myself saying to people, “everything that happens up there, (space), affects us lot down here, (on earth)”.

The Moon

Space Facts (2019) claims the moon is said to have been formed 4.6 billion years ago, approx. 30–50 million years after the formation of the solar system. The Moon is in synchronous rotation with Earth meaning the same side is always facing the Earth and is the earths only natural satellite, (Ibid).

The gravitational pull of the moon and earth is well known to be responsible for the rise and fall of the sea tides, (Byrd, 2019). The human body, depending upon sex and age is made up of between 50-75% water, (Helmenstine, 2019). So, when you think about it, if the moon can affect large bodies of water the size of oceans, rivers, lakes, then surely there is some truth in how we as humans can be affected also?

The Latin name for the moon is ‘Luna’. ‘Lunaticus’ means moon struck and is said to be the term associated with lunatic, the archaic name given to those who were seen to be mentally unstable, dangerous or foolish by those professing to be in the know. Folklore often have us believe the moon can make people shapeshift into a wolf on the night of a full moon following a bite or scratch from another werewolf.  

Moon and Criminality

A study in 1984 by Thakur and Sharma into whether the moon really does influence people’s moods, making them more aggressive, found criminality was ‘likely’ to increase on nights with a full moon. Another study by Calver et al in 2009 also suggests the full moon was responsible for a rise in violent and acute behavioural disturbance resulting in a 23% increase in admissions to psychiatric facilities. The same study suggests this is twice as many as other moon phases. This research is contradicted by Rahula et al in 2019 following their analysis of the data of 17,966 individuals treated at 15 different psychiatric wards over 10 years, which claims there is no evidence of increased aggression due to a full moon.

So, while aggressive or criminal behaviour is still very much open for debate, research by Wehr, (2018), claims to have discovered correlations between the moon’s orbital cycles and mood cycles of 17 patients with bipolar Disorder. Tung, (201) explains Psychiatrist Tom Wehr’s research is said to have stemmed as far back as the 1970’s when he was a young researcher at the National Institute of Mental Health. Wehr noticed patients with bipolar appeared to alternate between mania and depression in a rapid manner, with an almost bi-monthly shift between depression and mania.

Taking a longitudinal study approach across 20 research subjects, Wehr tracked biological variables such as; diet, sleep patterns, hormones, motor activity, bloodwork and moods. Wehr put forward various thoughts, but when his subject’s mania appeared to last for around 3-4 weeks with a switch to depression lasting the same length of time soon after, he began to take a closer look at a possible link between moon cycles and her gravitational pull on the earth’s oceans.

Spring and Neap Tides

Time and (2020) explain tides follow a lunar day, said to be 24 hours and 50 mins with a move from high to low tide every half a lunar day. This means we have high and low tides twice daily. High and low tides differ depending upon whether the moon is new or full, as it is this point when they are simultaneously aligned with the tides created by the sun and Earth.

Together the gravitational forces of both solar and luna tides pull the ocean’s water in the same direction. Effectively these tides are stronger and are known as Spring Tides, (nothing to do with the season). The gravitational force of the lunar tide and solar tides are at their lowest around the half-moon point of the lunar cycle. Tides at this point are known as Neap Tides.


Wehr suggested the circadian rhythm of sleep, which is traditionally linked to the solar day, (24 hours) slowed down in his bi-polar subjects and they became more attuned to the luna day, (24 hours and 50mins). This moved their circadian rhythm of sleep from the solar to the luna day, meaning they became more in tune with luna tides than solar tides. In essence suggesting spring tides are the stronger celestial phenomena and can cause an increase in mania, whilst the neap tides are not as powerful resulting in a slump in mood.

Either way, I know I tend to feel more energised when the moon is close to earth, (new moon) and tend to have an energy slump around a full moon when the moon is furthest away from earth.

By Lisa Watson


Avery, D. H. and Wehr, T.A. (2018) Synchrony Of Sleep‐Wake Cycles With Lunar Tidal Cycles In A Rapid‐Cycling Bipolar Patient

Byrd, D, (2019) Tides, And The Pull Of The Moon And Sun

Calver, L. A., Stokes, B. J. and Isbister, G. K. (2009) The Dark Side Of The Moon in Medical Journal of Australia, 2009; 191 (11): 692-694.

Helmenstine, A. M. Ph.D. (2019), How Much Of Your Body Is Water? The Percentage Of Water In The Human Body Varies By Age And Gender

Moon Facts, (2019)

Rahula, G., Nolan, D.R., Bux, D.A. and Schneeberger A. R. (2019) Is It The Moon? Effects Of The Lunar Cycle On Psychiatric Admissions, Discharges And Length Of Stay in Swiss Medical Weekly.  2019;149: w20070

Thakur, C.P and Sharma, D. (1984), Full Moon And Crime in British Medical Journal, 1984; 289(6460): 1789–1791.

The Moon’s Effect on Ocean Tides (2020)

Tung, L, (2019), Does the Mon affect Bipolar Disorder

Wehr, T.A. (2018) Bipolar Mood Cycles And Lunar Tidal Cycles in Molecular Psychiatry, 2018 Apr; 23(4): 923–931.

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