suggest this may be due to lunar influences on mood. Another study has found contradictory results and questioned these claims. Meta-analyses A meta-analysis of thirty-seven studies that examined relationships between the Moon's four phases and human behavior revealed no significant correlation. The authors found that, of twenty-three studies that had claimed to show correlation, nearly half contained at least one statistical error. Similarly, in a review of 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. A 1978 review of the literature also found that lunar phases and human behavior are not related. Sleep quality A 2013 study by Christian Cajochen and collaborators at the University of Basel suggested a correlation between the full Moon and human sleep quality. However, the validity of these results may be limited because of a relatively small (n=33) sample size and inappropriate controls for age and sex. A 2014 study with larger sample sizes (n1=366, n2=29, n3=870) and better experimental controls found no effect of the lunar phase on sleep quality metrics. A 2015 study of 795 children found a three-minute increase in sleep duration near the full moon, but a 2016 study of 5,812 children found a five-minute decrease in sleep duration near the full moon. No other modification in activity behaviors were reported, and the lead scientist concluded: "Our study provides compelling evidence that the moon does not seem to influence people's behavior." A study published in 2021 by researchers from the University of Washington, Yale University, and the National University of Quilmes showed a correlation between lunar cycles and sleep cycles. During the days preceding a full moon, people went to bed later and slept for shorter periods (in some cases with differences of up to 90 minutes), even in locations with full access to electric light. Finally, a Swedish study including one-night at-home sleep recordings from 492 women and 360 men found that men whose sleep was recorded during nights in the waxing period of the lunar cycle exhibited lower sleep efficiency and increased time awake after sleep onset compared to men whose sleep was measured during nights in the waning period. In contrast, the sleep of women remained largely unaffected by the lunar cycle. These results were robust to adjustment for chronic sleep problems and obstructive sleep apnea