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Are humans more aggressive during a full moon?


Is it true that we are more agressive during the night when there is a full moon?
If true, could this be a remnant from times where we needed to hunt for our food and so could see more at night when there was a full moon?

Source of question: article


This seems to be a piece of pseudoscience commonly seen these days. The truth is that this effect has never been statistically observed.

From the Skeptics This Site site:

Ivan Kelly, James Rotton and Roger Culver (1996) examined over 100 studies on lunar effects and concluded that the studies have failed to show a reliable and significant correlation (i.e., one not likely due to chance) between the full moon, or any other phase of the moon, and each of the following: The homicide rate, traffic accidents, crisis calls to police or fire stations, domestic violence, assassinations, kidnappings, aggression by professional hockey players, violence in prisons, assaults, gunshot wounds, stabbings

… and many more seen here.


7 Ways The Full Moon Supposedly Affects Your Body

When I was a kid, my older cousin told me that it wasn't safe to go outside at night during a full moon. "It can make people crazy, you know," they said with all the teenage authority they could muster. Their attempt to freak me out worked, and I swallowed the lie hook, line, and sinker. I believed that the full moon affects the human body for way longer than I should have, and to this day, still get a little creeped out when I see a big round moon lighting up the sky.

For about as long as people have turned their faces upwards to marvel at the bright celestial bodies, the moon has been regarded as a powerful entity. As it turns out, I was not the only one to attribute special powers to the full moon. Beliefs that a full moon can change and control the human biology or behavior still persist to this day. The European folkloric creature of the werewolf still features in our movies and TV shows, and the phrase "must be a full moon" continues to pepper our conversation, explaining the unexplainable. But there is little factual evidence to support them. It seems the lunar cycle cannot control our periods after all. Phew!

Here are the many ways that the full moon supposedly affects the human body. Be sure to read through them so next time an older cousin tries to frighten you, you can show them the facts (and make them buy you a soda).


Moon Affects Ocean Tides, Can it Affect Humans?

Others thought it was bad luck to look at the full moon through the branches of a tree, she said.

Brady also said that some American Indian tribes considered the full moon to be the best time to detox and take part in "sweat lodge" rituals.

Their thinking was that "at that point, the moon's pull is going to pull more out of you," Brady said.

To be fair, there is a hint of logic to the myths linking the moon and human behavior. Earth, much like the human body, is composed mostly of water. If the moon's gravitational pull can affect ocean tides, so the reasoning goes, couldn't it also affect a person's body?

But the science doesn't bear this out.

"Published [research] does not confirm that there is a change in the amount of violence, reported crimes or aggressive behavior during a full moon," Eric Chudler told ABC News. Chudler, a research associate professor in bioengineering at the University of Washington in Seattle, has studied more than 100 research papers on the purported effects of the full moon on human affairs.

Nurses, Police Officers Link Full Moon to Chaos

Still, people persist in believing otherwise. Studies have found that police officers and hospital workers are among the strongest believers in the notion that more crime and trauma occur on nights when the moon is full.

Dr. David Mandell of the Children's Hospital in Pittsburgh and some colleagues studied existing data on health-care myths and did a 2005 study of area nurses. He said he found that 69 percent of surgical nurses in his study believed that a full moon led to more chaos and incoming patients that night.

"It is unbelievable how many nurses in southwest Pennsylvania believed in the superstitions," he told ABC News. But he said that it's simply part of the culture of medicine.

"In any high-stress, fast-paced field like medicine, superstitions run rampant when you feel a loss of control. This is especially true of emergency environments [because] you never know what will walk in. You need some way to explain the unpredictability of your environment," he said. "It passes on from senior to junior people in hospitals -- like old times telling it to new residents coming in."


Full Moon Crazy

By Marissa Kantor published January 1, 2005 - last reviewed on June 9, 2016

Q: Does the full moon influence human behavior?

A: Everything from increases in violent crime and psychotic behavior to stock market fluctuations has been blamed on the effects of the fully illuminated moon. In 19th-century England, lawyers used the "guilty by reason of the full moon" defense to claim that their "lunatic" clients could not be held accountable for acting under the moon's influence.

In his 1978 best seller, How the Moon Affects You, psychiatrist Arnold Lieber argued rather unscientifically that the moon has an effect on the human body (which is 65 percent water) that is similar to its pull on the ocean's tides.

Despite these many assertions, scientists who have investigated the matter have come up empty-handed. University of Sydney researchers found no link to the moon's cycle in two separate studies, one of violent or aggressive behavior, the other of dog bites that required human hospitalization.

And in an analysis that ought to put to rest any lingering doubts, Ivan Kelly, a psychologist at the University of Saskatchewan, found in a review of over 100 studies of lunar cycles and behavior -- including emergency room admissions and suicide attempts -- nothing to suggest that humans are affected by Earth's satellite.

So why do 81 percent of mental health professionals, according to a University of New Orleans study, believe that lunar cycles affect human behavior? Part of the reason is historical: The illuminated moon played a more prominent role for our ancestors as both a calendar and a night-light. Before electric lighting became ubiquitous, a bright moon was more likely to disrupt sleep, producing widespread grouchiness.

Kelly also cites what psychologists call confirmation bias, selective thinking whereby we seek out information that confirms our beliefs and ignore evidence that challenges them. Says Kelly, "Some beliefs are just exciting to hold, whatever the evidence."


Pets get injured

Cats and dogs seem to find more mischief and get injured more often during the full moon. One study investigating this correlation &mdash frequently noted by veterinarians and other workers in animal care &mdash found a 23 percent increase in cat visits and 28 percent increase in dog visits to emergency rooms on nights when the moon was fuller. The researchers were unable to determine why, exactly, pet behavior becomes more precarious during this time, but suggested that it could simply result from pets spending more time outsideat night when the moon is brighter.


Does a full moon actually affect people’s behavior?

I admit that New Yorkers are not known for their superior driving ability, but on this one night the drivers seemed especially erratic. People kept cutting me off. One guy sped right through a red light, barely missing a collision with the crossing traffic. And some genius, perhaps British but probably not, forgot that in this country we drive on the right side of the road.

I thought about what made this night particularly favorable for lunatic drivers compared to any other. It wasn’t St. Patrick’s Day, New Year’s or very late at night, so drunk driving didn’t seem to fit. Only when I got out of my car and looked up did I conceive a possible explanation: the full moon.

The legend of the full moon’s effects on human behavior has existed for centuries, popularized by the myth of the werewolf. The words “lunacy” and “lunatic” are derived from the same Latin root that gives us the word “lunar,” as people often attributed intermittent insanity to the phases of the moon. While many people believe the full moon influences behavior, scientific studies have found very little evidence supporting the “Lunar Effect.”

In 1978, University of Miami psychologist Arnold Lieber wrote the book The Lunar Effect: Biological Tides and Human Emotions. He argued that the moon influences day-to-day behavior and concluded that homicides increased during the full moon after analyzing Miami’s crime records. Similar crime studies during that same time period, however, found no such relationship.

Then, in 1986, researchers from the University of Saskatchewan in Canada combined the results of about 100 studies and found “no causal relationship between lunar phenomena and human behavior.” They discovered statistical flaws in many of the papers that claimed to find such a link. They even reanalyzed Lieber’s homicide data and found no correlation.

More recently, numerous studies have been conducted by intrigued researchers, with most attempts to blame the moon for everything from suicides to vomiting after surgery coming up empty.

So with all this evidence to the contrary, what makes the full moon lunacy theory still so popular? Perhaps it’s the media, who know people are more likely to read a crime story if some police officer blames it on the moon. Or maybe people just want to hold onto an urban legend that’s been around for hundreds of years.

A more scientific answer may be selective memory. If some bizarre murder or car accident occurs, people are probably more likely to remember it if it happened during the night of a full moon.

After reading up on some studies — including one from the authority on this topic, the University of Saskatchewan — I’ve decided that the full moon was not responsible for my experience on the road that night. Perhaps I selectively forgot the thousands of other times I encountered lunatic motorists. Though I have no scientific evidence to prove it (just years of experience), I’m going with the theory that New Yorkers are just really bad drivers.


Are humans more aggressive during a full moon? - Biology

We all know a full moon is supposed to bring werewolves and vampires out into the open. Belief in its power to drive us mere mortals a little mad is ancient and widespread. Such notions even gave rise to the word lunacy.

Speak to police officers or staff in hospital emergency departments, and some will insist there are more accidents, violent incidents and psychiatric admissions when the Moon is full. In 2007, the police force in the British seaside resort of Brighton even went as far as to employ extra officers during full moons.

The ability of the moon to influence our behaviour is undoubtedly an idea with broad appeal. Beyond folk tales and anecdotal evidence, the theory has been the subject of hundreds of studies. Just this summer there was new research which found that people spending the night in a sleep laboratory rated their sleep quality as 15 per cent lower when there was a full moon, even though they couldn’t see it or any extra light it produced, and they took on average five minutes longer to get to sleep.

This study got a lot of publicity, however there were only 33 people in it and even the authors were cautious about inferring too much from the results. Combining the results of multiple pieces of research in a meta-analysis is one way to ensure findings have stronger statistical foundations. US psychologists James Rotton and Ivan Kelly took this approach in 1985, combining the findings of 37 studies on the effects of the lunar cycle. They concluded it was unrelated to the numbers of psychiatric admissions, murders, car accidents, suicides and crimes.

When they looked at the individual studies that did find links, they found there were often other explanations, such as the full moon happening to coincide with a holiday or a weekend when more trouble occurs anyway. For every study that revealed more problems when the Moon was full, another showed there were fewer. Rotton and Kelly found that if you were trying to use these statistics to predict people’s behaviour, the strength of any association was very weak. Knowing the Moon’s phase only made their predictions marginally better – to the tune of 1%.

Since then, further studies have been carried out, again with mixed results. A 1992 review of 20 studies on the relationship between the phase of the Moon and the number of people contemplating suicide concluded there was no evidence for a link. Once again researchers who believed they had identified a link had often failed to take account of variations linked to the days of the week on which they happened to fall.

One difficulty that may have helped give the influence of the full moon unwarranted legitimacy is the so-called “file drawer” problem, where journals are more likely to accept studies for publication where an effect was found, than those where it wasn’t. So no one knows how many studies which found the Moon had no influence might be languishing in filing cabinets.

Then there’s the question of how the Moon could influence our behaviour. One theory is that just as it affects the tides, it exerts its influence on the water in our bodies. But the Moon is smaller than the Earth, so its gravitational pull is correspondingly less powerful. What’s more it exerts the same force on us regardless of whether it’s new or full. Others have proposed that it’s the light from a full moon that affects people, yet it has the luminance of just a quarter of that of a candle.

Reality bites

But, say believers, what about the strange case of the biting animals? When doctors at the Bradford Royal Infirmary in the north of England examined two years of medical records, they found twice as many patients were admitted with dog, rat, cat and horse bites when there was a full moon than when it was new. What we don’t know is why. Did these bites even happen at night? It has been suggested that the full moon might not impact the behaviour of the animals directly, but the mites that feed off them. However in the same issue of the journal in which the Bradford work was published, researchers who analysed records of patients admitted to Australian hospitals for dog bite injuries over 12 months found that once they take into account the day of the week the bites happened, then the full moon made no difference.

So if the evidence for any link is so slim, why are so many people convinced it’s a real phenomenon? It could be an example of the confirmation bias, where people are more likely to notice and remember information which fits in with what they already believe. Police or medical staff look up one night, notice how bright it is, and see the full moon. They then make a connection between this and the busy night they’re having. But of course when there’s a crescent moon they’re less likely either to notice it or to make any connection.

How might this idea so entrenched in legend have caught on in the first place? One interesting suggestion is that before we had outdoor lighting there might have been a link because homeless people susceptible to mania and seizures might have been more likely to suffer them when deprived of sleep by the brightness of full moons.

Some argue the full moon’s power only affects some people, and as a result it is not surprising that studies examining its influence on the general population usually fail to find an effect. The way forward, they say, is to study the individuals who claim to be affected.

Who knows, perhaps such an approach will reveal that the full moon really does bring out the wild side in some of us. But for the moment, for those interested in sober assessment of evidence, it’s an idea that’s hard to stand up.

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There's more violence during full moons, say police

A full moon doesn't just encourage werewolves. It also brings out the worst in the Great British Hooligan, police have discovered.

Cases of anti- social behaviour rose noticeably on the brightest nights, according to a study by the Sussex force.

"There is definitely a trend," said Inspector Andy Parr, who is responsible for patrols in Brighton at weekends. "With each full moon the number of disturbances recorded increased significantly."

Scroll down for more.

The force is now preparing to put extra officers on the streets during full moons in a bid to curb unruly behaviour.

Inspector Parr, who led the study, said its findings are too striking to dismiss as coincidence.

He compared the number of violent crimes recorded in the region last year with the date of each full moon and discovered a distinct correlation.

"I'm aware that this is just one of many things that can influence public disorder but if you speak to ambulance staff they will tell you exactly the same," he said.

"It may be dismissed as an old wives' tale but there's plenty of other research to suggest that the moon has an impact on human behavioural patterns.

"Last weekend we had a full moon and it was busier in Brighton than it has been previously."

This is not the first time that a link between full moons and extremes in human behaviour has been identified.

A study published by German scientists in 2000 claimed the full also sparked a rise in binge drinking.

They checked the police arrest reports and blood-alcohol tests of 16,495 offenders. Most of those with an excess of 2ml of alcohol per 100ml of blood - drunk, under German law - had been caught during the five-day full moon cycle.

Another study, published in 1998, discovered a rise in violent incidents among the 1,200 inmates at Armley Jail in Leeds during the days either side of a full moon.

During the first and last quarter of each lunar month there was a marked increase in aggressive incidents.

But during the other period of every lunar month, there were far fewer incidents and none at all on some days.

The Daily Mail's astrologer Jonathan Cainer said Inspector Parr had shown "great courage" by publicly making the link between anti- social behaviour and a full moon.

"Privately it's not just the police who acknowledge that more dramatic things happen around the full moon," he said.

"The fire brigade and ambulance service will both say exactly the same.

"The ocean tides rise and fall with the moon and so do the tides of human emotion. At new moon our inner seas are deep but still.

"At full moon it is as if they are being furiously whipped up by a wind. Full moon aggression can, however, be turned into motivation. That's why many people achieve more during a full moon.

"But the reason why we have the word "lunatic" is because people famously go crazy when the moon is full. So, now that we have official confirmation of how a full moon can provoke violent crime, the only solution is to give the moon an Asbo.

"It's clearly inciting people to disobey the law and behave in a reckless manner."


7 Ways The Full Moon May Affect Your Health

Here are some interesting things researchers have found regarding the full Moon and its effects on your health.

1. Heart

Can the Moon’s cycles have an effect on your heart? Apparently so, but not in the romantic sense. A study published in the Indian Journal of Basic and Applied Medical Research found that when exercising, your heart is at its peak performance during a full and new Moon. So check the phases of the Moon before hitting the gym!

2. Brain

Much like the Moon is responsible for the ebb and flow of tides, because our brains are a significant source of water, Dutch researchers hypothesize the Moon’s gravitational pull could similarly have an effect on your brain, causing erratic behavior. Read: Do Full Moons Make People Crazy?

Other studies by British scientists reveal that a full Moon may actually decrease seizure activity in epileptics. In these cases, however, researchers suggest it may be due to the brightness of the Moon rather than its phases. When the Moon was bright, participants had fewer epileptic seizures. They attribute this to the hormone melatonin, which is naturally secreted in your brain when the Sun goes down, hence signaling it’s time to sleep. In epileptics, they surmise, the brightness of the full Moon counters this release, thus decreasing seizures.

We also hear from our Facebook fans all the time: complaints of headaches and migraines around the time of the full Moon. While no scientific correlation is made between migraines and the full Moon, full Moons can disrupt sleep (see #4) which, in turn, disrupts hormone levels, thus triggering headaches.

3. Kidneys

A 2011 study published in the Journal of Urology found that kidney stone pain increased significantly during a full Moon. And in another study, English researches found that generally, more patients were admitted to hospitals with urological emergencies during this time, too. Conversely, the new Moon caused a “calming effect” for people with these conditions.

Coincidence? Maybe not. One theory behind these conclusions is that the kidneys, like other organs and the human body itself, are made up of about 60 percent water, and just as lunar activity can affect our oceans, creating powerful and predictable tides, the Moon may affect the workings of these organs, causing a noticeable ebb and flow in times of calm and pain. Not all researchers agree, but there is enough evidence that additional studies are in the works.

4. Sleep

A 2013 study published in Current Biology reviewed the sleep patterns of participants over three days in which they were allowed to fall asleep at will in a controlled area that had neither clocks nor outside light. When the data was compared to the phases of the Moon, researchers determined participants not only had lower melatonin levels during bright Moon phases, but they also took 5 minutes longer to fall asleep, slept 20 minutes less in general, and had 30 percent less REM sleep. And if you’re not getting enough sleep, your health suffers. Try these tricks to get a good night’s sleep!

5. Menstrual Cycle

A woman’s average menstrual cycle is 28 days, which is quite similar to the 29+ day lunar cycle. This timing may be more than coincidence according to Chinese researchers who discovered that almost 30 percent of all the women monitored ovulated at the full Moon and menstruated during the new Moon. In some cultures, there is even a name for this phenomenon, called White Moon Cycle, which essentially mirrors the fertility of the Earth which is said to be most fertile under full moonlight.

6. Birthrate

Japanese researchers discovered something interesting: there was a significant increase in the number of births when the gravitation of the Moon to the Earth was most powerful. While researchers admit they are still unclear on exactly how or why this relationship exists, they say it might help healthcare professionals and pregnant women better prepare.

Additionally, one Italian study examined more than 1,200 births over three years and found a higher number of babies born in the two days after a full Moon.

7. Injuries

Since the full Moon can affect our behavior in certain ways, it should come as no surprise that we are more prone to accidents or illness during this time, according to some. One 2011 study published in World Journal of Surgery found that over 40 percent of medical personnel believe in “Full Moon Madness” among patients. It was also revealed that emergency calls for all sorts of conditions actually increases by 3 percent whenever there’s a full Moon, and then drops by 6 percent during a new Moon.

In 2008 British researchers found a link between the lunar cycle and what doctors call “medically unexplained stroke symptoms,” where patients develop complaints such as headaches, numbness and coordination issues but have nothing physically wrong with them.

What do you think—do you experience any changes in your health during the full Moon? Share your stories with us in the comments below.

Cynthia McMurray

Cynthia McMurray is a freelance writer and journalist, and publisher of a national health magazine. She has written books for leading health professionals and is the owner of Write Words, a consulting business for writers. She lives in Halifax, Nova Scotia. Her article, Animals' Amazing Sense of Direction appears in the 2021 Farmers' Almanac.

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Do Full Moons Really Affect Our Behavior?

People who believe that Moon phases affect human behavior point out that the human body is about 60% water. If the phase of the Moon can affect ocean tides, and even cause a bulge in the Earth’s crust, surely it would exert an effect of human beings, they reason.

And, of course, one of the most popular features in the Farmers’ Almanac is our Best Days calendar, which recommends specific days to do everything from plant root crops to cut hair for increased growth, based on the phases of the Moon and other factors. Readers swear that they see better results in their endeavors when they follow these recommendations.


Another possibility is that patients are responding to the Moon’s gravitational pull in the same way the oceans do: through tidal forces

However, although cryptochrome is also an essential component of the human circadian clock, it works slightly differently to the version operating in fruit flies. “It looks like human and other mammalian cryptochrome no longer binds flavin, and without flavin, we don’t know how the magnetically sensitive chemistry would be triggered,” says Alex Jones, a physicist at the National Physical Laboratory in Teddington, UK. “From that regard, I think it is unlikely that [human] cryptochromes are sensitive to magnetic fields, unless there are some other molecules inside humans that can detect magnetic fields.”

Another possibility is that Wehr and Avery’s patients are responding to the Moon’s gravitational pull in the same way the oceans do: through tidal forces. A common argument against this is that, although humans are up to 75% water, they possess far smaller quantities of it than an ocean. “Humans are made out of water, but the pull is so weak that it would be difficult to see how that would work from a physical point of view,” says Kyriacou.

Even so, he nods to studies in Arabadopsis thaliana (a weed considered a model organism by biologists who study flowering plants) suggesting that their root growth follows a 24.8-hour cycle – the amount of time it takes the Moon to complete one full orbit of Earth. “These are incredibly small changes, which can only be detected with extremely sensitive devices, but now there are over 200 publications to support this,” says Joachim Fisahn, a biophysicist at the Max Planck Institute of Plant Physiology in Potsdam, Germany.

The gravitational pull of the Moon is what causes the daily tides of the world's oceans and seas (Credit: Getty Images)

Fisahn has modelled the dynamics of clusters of water molecules within single plant cells and found that daily variations in gravity caused by the Moon’s orbit would be enough to cause a net loss or gain of water molecules from the cell.

“The volume of water molecules – even if it is in the nano-range – will respond to any tiny gravitational change,” he says. “As a consequence, there will be movement of water molecules through water channels, meaning water will move from inside the cell towards the outside or vice versa, depending on the direction of the gravitational force – and this could have an effect on the whole organism.”

He is now planning to test this in the context of root growth, by studying plants with mutated water channels to see if they have altered growth cycles.

If plant cells really are sensitive to such tidal forces, then Fisahn sees no reason why human cells couldn’t be as well. Given that life is thought to have begun in the oceans, some land organisms may still retain the machinery to predict the tides, even if it no longer serves a practical use.

Even if the mechanism eludes us for now, none of the scientists contacted for this article dispute Wehr’s basic finding: that his bipolar patients mood swings are rhythmic, and that these rhythms appear to correlate with certain gravitational cycles of the Moon.

Wehr for one is keeping an open mind about the mechanism and hopes others will see them as an invitation to investigate further. “I haven’t answered how this effect is mediated, but I think the things that I found raise those questions,” he says.