It is the very error of the moon;
She comes more near the earth than she was wont,
And makes men mad.
~William Shakespeare, Othello, Act 5, Scene 2, 1

On March 19 we experienced the largest full moon in 20 years. Although perhaps too early to tell, I wonder if this super moon led to an increase in drug overdoses, aggressive behaviour, depression and suicides, more hospital admissions and accidents. The moon has often been connected to such things –at least anecdotally – and it seems likely that the influence of heavenly bodies on humans and other animals has been discussed since the beginning of recorded time.

Contemplation of the moon has played a significant role in literature, philosophy, and medicine with Greek and Roman notables including Hippocrates, Pliny the Elder, and Plutarch linking the moon to a range of mental states. In fact, the word lunacy comes from the Latin luna, meaning moon, and it has even been hypothesised that the gravitational pull of the moon on water to create tides on the planet has similar effects with “human tidal waves”.

In 1845 the Lunacy Act became law in England and it made a distinction between appropriate and inappropriate behaviour based on the lunar cycle, whereby some behaviours were considered acceptable two weeks before a full moon, but not after.

The menstrual cycle of many younger women in particular coincides with lunar cycles, and a study of 826 women in China published in 1986 found that close to one-third of participants had a menstrual cycle that occurred during the new moon phase, and that the average menstrual cycle lasts exactly one full lunar cycle.

Fertility rates appear to be linked to lunar cycles, and it seems hardly coincidental that studies have shown that births vary statistically throughout the year on a period of 29.53 days - the exact length of the lunar cycle, and that human gestation is 266 days or nine complete lunar cycles.

Many species of mussels and sea urchins synchronise their reproductive cycles to the moon and it has been well-documented that worms and crabs in the South Pacific and elsewhere come to the surface and reproduce during the full moon.

Observational studies of animal behaviour also suggest that lunar cycles have an effect, and a study between 1997 and 1999 of people admitted to an emergency department for animal bites found that bites increased significantly during full moons.

In a 2004 study Selim Benbadis and colleagues discovered that full moons were correlated with non-epileptic seizures, and that epileptic seizures were at the lowest frequency level during full moons, and highest during the last quarter of the lunar cycle.

A study on an incarcerated population by Armando Simón published in 1998 considered the effect of lunar cycle on reported crimes in a Texas prison with 1,300 inmates. He concluded that there was no statistically significant correlation between moon cycles and crime rates.

By contrast an earlier study published in 1976 by Jodi Tasso and Elizabeth Miller found that rates for crimes, including rape, robbery, assault, auto theft, and drunk and disorderly conduct were significantly higher during a full moon.

Researchers Susan De Voge and James Mikawa examined data gathered between 1972 and 1973 from 7,844 telephone calls to a 24-hour crisis line in Reno, Nevada. They compared type of call with lunar cycle and concluded that call volume and suicide threat calls varied significantly across lunar phases, but that this didn’t correspond with full moons. Instead first quarter and new moons were when more activity was reported.

Moosa Zargar and colleagues published a study in 2004 of admissions to three emergency rooms in Tehran, Iran, over a 13 month period, and discovered that full moons had no impact on the number of trauma patients seen, rates of assaults or suicides, or the severity of traumatic injuries. By contrast a study in the United States published in 1973 concluded that admissions to a mental health centre were positively correlated with full moons.

In the workplace many have suggested that lunar cycles can be “felt” or observed in the behaviour of colleagues, and that the howl of the werewolf can be heard sub-audibly as behaviour becomes edgier and interpersonal relations get pushed to the breaking point. At the moment there is no clear scientific evidence to support such a conclusion. However, a 1991 study by Joanne Sands and Lynn Miller discovered surprisingly that full moons were associated with slightly lower rates of absenteeism.

Obviously no clear pattern of behaviour fits with full moons in particular, but a picture is emerging due to decades of research to suggest that many facets of human behaviour are influenced by the lunar cycle in complex ways. Clearly, much more work is needed on this topic.

Dr. Michael Mehta is a sociologist who focuses on environmental and health risk issues. 

Opinions expressed in this column will usually be those of the author and do not necessarily reflect those of The Shingle.