Lunar effect purported lunar-lunacy connection, and at least 20 published studies on the purported lunar-birthrate connection. This has allowed several extensive literature reviews and meta-analyses to be produced, which have found no correlation between the lunar cycle and human biology or behavior. Examples of the belief have been found in ancient Assyrian/Babylonian writing. Claims of a lunar connection have appeared in the following contexts: It is widely believed that the Moon has a relationship with fertility due to the corresponding human menstrual cycle, which averages 28 days. However, no connection between lunar rhythms and menstrual onset has been conclusively shown to exist,
Menstrual synchrony 7.5 days. The mean difference in cycle onset was calculated for the beginning, middle, and end of the study for the pairs and triples of women. Ziomkiewicz found no statistically significant difference from the 7.5 day expected difference at either the beginning, middle, or end of the study. She concluded that there was no evidence of menstrual synchrony. H. Clyde Wilson argued that at the start of any menstrual synchrony study, the minimum cycle onset difference must be calculated by using two onset differences from each woman in a group. For example, suppose two women have exactly 28-day cycles. The