Question

Read the following article to assess if this claim scientific by answering the questions that follow:

The term lunar effect refers to correlations between specific stages of the roughly 29.5-day lunar cycle and behavior in humans or other living things. In some cases these rhythms may depend on external cues, such as a greater or smaller amount of moonlight due to the moon's phases. A considerable number of studies have examined the effect on humans. By the late 1980s, there were at least 40 published studies on the purported lunar-lunacy connection,and at least 20 published studies on the purported lunar-birthrate connection. However, several extensive literature reviews and meta-analyses found no correlation between the lunar cycle and human biology or behavior.

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Other studies found evidence that those with mental disorders i.e. Schizophrenia generally exhibit 1.8% of increased violent or aggressive episodes during the full Moon, but a more recent study found no such correlation to that of non-schizophrenic human beings^. An analysis of mental-health data found a significant effect of Moon phases, but only on schizophrenic patients.

A recent study of 33 volunteers that did not account for age and sex found a statistically significant connection between sleep quantity and quality and lunar phases, even though the subjects could not see the moon or its light.  A July 2013 study carried out at the University of Basel in Switzerland suggests a correlation between the full Moon and human sleep quality.^[5] Professor Cajochen and colleagues presented evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues. Studying 33 volunteer subjects, the researchers found that subjective and objective measures of sleep varied according to lunar phase and thus may reflect human circalunar rhythmicity. Stringently controlled laboratory conditions, in a cross-sectional setting, were employed to exclude confounding effects such as increased light at night or the potential bias in perception. Measures of lunar influence on sleep structure, electroencephalographic activity during non-rapid eye movement sleep (NREM), and secretion of the hormones melatonin and cortisol, were retrospectively analyzed.   Cajochen said: "The lunar cycle seems to influence human sleep, even when one does not 'see' the Moon and is not aware of the actual Moon phase."

However, there are suggestions that the 2013 Cajochen study is faulty 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 3 minute increase in sleep duration near the full moon, but a 2016 study of 5,812 children found a 5 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."

1. What are the scientific bases for the claim that there is a lunar effect on human behavior?

Answer 1

Scientific bases for the claim that there is a lunar effect on human behavior?
The given articles summarise several important studies carried out to assess to lunar cycles have any effect on human behavior. Particularly the studies focused on schizophrenic patients and sleep-pattern of humans during full moon days. There is a large number of scientific publications in this regard, but unfortunately, none of them are conclusive. Almost all the experiments are prone to variables and non-repeatability. From the recent studies involving a large number of children, we can conclude that there is little influence on the moon cycle that cannot be conclusively attributed to lunar effects only. The small increase of a decrease of 3 - 5 minutes of sleep of a total 8 - 10 hours of sleep duration among children is questionable. Hence at this point, there is no scientific base for the claim that there is a lunar effect on human behavior.