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The lunar effect is a theory which overlaps into sociology, psychology and physiology suggesting that there is correlation between specific stages of the Earth's lunar synodic cycle and deviant behavior in human beings. It is a pseudoscientific theory, however. The claims of a correlation of lunar phases to human behavior do not hold up under scientific scrutiny. Over the past 30 years, even more evidence has emerged to stress that this is pseudoscience.[1]

The theory is sometimes also referred to as the Transylvanian hypothesis or the Transylvanian effect in scholarly literature.[1]


While the exact origins of this theory are ambiguous historically, this belief has been around for many centuries. The term lunacy itself is derived from the name of Luna, the Roman moon goddess. The connection between the words lunar and lunatic can also be demonstrated in other languages, such as in Welsh, where these two words are lloer and lloerig. Perhaps the most famous myths arising from this theory is the legend of the werewolf.

Scientific research on theoryEdit

The notion behind the lunar effect has fascinated many behavioralists and warranted many experiments and studies. Most experiments, however, have found no correlation between the variables and, thus, refuted the theory.

There are some studies which have results the researchers claimed supported the theory. For example, a study concluded that schizophrenic patients show signs of deterioration, in terms of quality of life and mental well-being, during the time of a full moon.[2] Some researchers have claimed that there were strong positive correlations between physiological changes such as induced seizures in epileptic and non-epileptic people and the full moon period in studies they conducted. One study concluded that a statistically significant correlations for gastrointestinal bleeding among males in particular during this time.[3] However, most of these findings are based on small-scale research.

On the other hand, the majority of scientific research seems to refute the theory of the lunar effect. Psychologist Ivan Kelly of the University of Saskatchewan (with James Rotton and Roger Culver) did a meta-analysis of thirty-seven studies that examined relationships between the moon's four phases and human behavior. The meta-analysis revealed no correlation. They also checked twenty-three studies that had claimed to show correlation, and nearly half of these contained at least one statistical error.[4] Kelly, Ronnie Martins, and Donald Saklofske evaluated twenty-one studies of births related to the phase of the moon and found no correlation. The scientific data "supports the view that there is no causal relationship between lunar phenomena and human behavior".[4] Template:Harvcol

A study of 4,190 suicides in Sacramento County over a 58-year period showed no correlation to the phase of the moon. A 1992 paper by Martens, Kelly, and Saklofske reviewed twenty studies examining correlations between Moon phase and suicides. Most of the twenty studies found no correlation and the ones that did report positive results were inconsistent with each other.[4]

Psychologist Arnold Lieber of the University of Miami reported a correlation of homicides in Dade County to moon phase, but later analysis of the data — including that by astronomer George Abell — did not support Lieber's conclusions. Kelly, Rotton, and Culver point out that Lieber and Carolyn Sherin used inappropriate and misleading statistical procedures. When more appropriate tests were done, no correlation between homicides and the phase of the moon was found.

Astronomer Daniel Caton analyzed 70,000,000[How to reference and link to summary or text] birth records from the National Center for Health Statistics, and no correlation between births and moon phase was found. Kelly, Rotton, and Culver report that Caton examined 45,000,000[How to reference and link to summary or text] births and found a weak peak around the third quarter phase of the Moon, while the full moon and new moon phases had an average or slightly below average birth rate.

In 1959 Walter and Abraham Menaker reported that a study of over 510,000 births in New York City showed a 1 percent increase in births in the two weeks after full moon. In 1967 Walter Menaker studied another 500,000 births in New York City, and this time he found a 1 percent increase in births in the two-week period centered on the full moon. In 1973 M. Osley, D. Summerville, and L. B. Borst studied another 500,000 births in New York City, and they reported a 1 percent increase in births before the full moon. In 1957 Rippmann analyzed 9,551 births in Danville, PA and found no correlation between the birth rate and the phase of the moon [5]

A fifteen month study in Jacksonville, Florida also revealed at least no lunar effect on crime and hospital room admittance. In particular:

  • There was no increase in crime on full moons, according to a statistical analysis by the Jacksonville Police Department. Five of the fifteen full moons had a higher than average rate of crime while ten full moons had a lower than average rate. The higher-than-average days were during warmer months.
  • Statistical analysis of visits to Shands Hospital emergency room showed no full moon effect. Emergency room admissions consistently have more to do with the day of the week. [6]


Religion and folkloreEdit

Across the world, there has been an abundance of pseudoscientific theories and superstitions based on this premise. One theory claims that the moon has a perceived relationship to fertility is due to the corresponding human menstrual cycle, which averages 28 days. [7] However, only about 30 percent of women have a cycle length within two days of the average. Furthermore, the cycle of lunar phases is 29.53 days long, so the cycles would soon get out of synchronization.[How to reference and link to summary or text] Some say that upon seeing the new moon you should hand over whatever silver you have in your pockets or handbag, which supposedly ensures prosperity for the following month.[How to reference and link to summary or text]

According to some traditions, prior to the advent of modern techniques, surgeons would supposedly refuse to operate on the full moon because of the increased risk of death of the patient through blood loss.[8]

In the newsEdit

As with most folklore and urban legends, the notion behind the lunar effect has also found its way into the news. For example, most recently, it has been alleged that the full moon may have influenced voter behavior in the US 2000 presidential election.[9]

Police in Toledo, Ohio claimed that crime rises by five percent during nights with a full moon,[10][11] while police in Kentucky have also blamed temporary rises in crime on the full moon.[12] This was based on there being three car chases within a four-hour period.

In the UK, a survey has found that car accidents rise by up to 50 percent during full moons.[13] Senior police officers in Brighton announced in June 2007 that they were planning to deploy more officers over the summer to counter trouble they believe is linked to the lunar cycle.[14] In January 2008, New Zealand's Justice Minister Annette King suggested that a spate of stabbings in the country could have been caused by the lunar cycle.[1]


  1. 1.0 1.1 Iosif, A. & Ballon, B. (2005). Bad moon rising: the persistent belief in lunar connections to madness. CMAJ, 173, 1498-1500.
  2. Barr, W. (2000). Lunacy revisited: The influence of the moon on mental health and quality of life. Journal of Psychosocial Nursing and Mental Health Service, 38 28-35.
  3. Roman, E.M., Soriano, G., Fuentes, M., Luz-Galvez, & M.,Fernandez, C. (2004). The influence of the full moon on the number of admissions related to gastrointestinal bleeding. International Journal of Nursing Practice. 10(6), 296.
  4. 4.0 4.1 4.2 Kelly, Ivan, Rotton, James & Culver, Roger (1986), "The Moon Was Full and Nothing Happened: A Review of Studies on the Moon and Human Behavior", Skeptical Inquirer, vol. 10, no. 2, pp. 129-43. Reprinted in The Hundredth Monkey - and other paradigms of the paranormal, edited by Kendrick Frazier, Prometheus Books. Revised and updated in The Outer Edge: Classic Investigations of the Paranormal, edited by Joe Nickell, Barry Karr, and Tom Genoni, 1996, CSICOP.
  5. Abell, George & Greenspan, Bennett (1979), "The Moon and the Maternity Ward", Skeptical Inquirer, vol. 3, no. 4, pp. 17-25. Reprinted in Paranormal Borderlands of Science, edited by Kendrick Frazier, Prometheus Books, ISBN 0-87975-148-7.
  6. Marshall, Konrad (2007-05-02), "Must be a Full Moon", The Florida Times-Union: C-1, 
  7.   Robert Todd Carroll (2003). The Skeptic's Dictionary: A Collection of Strange Beliefs, Amusing Deceptions, and Dangerous Delusions, John Wiley & Sons. ISBN 0-471-27242-6. Available online here.
  8. Roman, E.M., Soriano, G., Fuentes, M., Luz-Galvez, M.,Fernandez, C. (2004) The influence of the full moon on the number of admissions related to gastrointestinal bleeding. International Journal of Nursing Practice. Vol. 10;6, p296.
  9. #Y127; 24% of the U.S. Presidential Vote swayed by the Full Moon effect
  10. - Analysis shines light on full moon, crime
  11. Skeptic's Dictionary and Refuge: Mass Media Bunk
  12. includeonly>"Police busy for full moon", The Kentucky Post, E. W. Scripps Company, 2002-01-29.
  14. Police link full moon to aggression | The Guardian | Guardian Unlimited


  • Berman, Bob (2003). Fooled by the Full Moon - Scientists search for the sober truth behind some loony ideas, Discover, September 2003, page 30.
  • Sanduleak, Nicholas (1985). The Moon is Acquitted of Murder in Cleveland, Skeptical Inquirer, Spring 1985, 236-42. Reprinted in Science Confronts the Paranormal, edited by Kendrick Frazier, Prometheus Books, ISBN 0-87975-314-5.

See alsoEdit

External linksEdit

{{enWP|Lunar effect]]

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