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Can a Full Moon Affect Your Mood?

Does the Moon Make People Crazy?

By: Tim Clark

Does the Moon influence our behavior or emotions? There’s never been solid proof, but there’s some new evidence suggesting that the Moon can affect sleep—and it doesn’t matter whether you’re in the country or the city! Let’s explore the myths and reality of the Moon’s power.

The Luna-Lunacy Connection

Ancient authorities like Aristotle, Paracelsus, and Pliny the Elder thought some humans were driven crazy by the full Moon. The Latin name for the Moon—luna—is the root of modern words like “lunacy,” “lunatic,” and even “loon,” as in “crazy as a loon.”

Even today, many doctors, nurses, EMTs, police officers, and elementary school teachers agree that full Moons will bring out bizarre behavior—43 percent of healthcare professionals believe in what some call “the lunar influence,” as do 81 percent of mental healthcare specialists. But is there really a lunar connection to abnormal behavior?

Unless you plan to ask a werewolf (which we don’t recommend), it might be time to separate facts from fiction.

The Moon and Sleep

According to one scientific study conducted in 2021, people go to bed later and sleep for a shorter period of time in the days leading up to a full Moon. Specifically, people would go to bed 30 minutes later than average and sleep almost an hour less per night!

This makes some sense because the light from the Moon after sunset is brighter on the days leading up to a full Moon. However, here’s the surprising part: Studies found that it didn’t matter if you lived in a rural or urban environment (where you might find more light pollution). Sleep patterns were compared between people in two very different locations:

  1. Indigenous people in rural Argentina (the Toba/Qom communities) who don’t have any access to artificial light

  2. College students living in downtown Seattle, Washington, where the glare from city lights dims the light from the Moon and stars.

If the Moon’s brightness isn’t a factor, why do we stay up later and sleep less? One theory goes back to our ancestors and our long history before the industrial age. People paid attention to the Moon and relied on its “night light” for hunting, fishing, and other social activities. Think of the “Harvest Moon” in the autumn, so-named because it provided several nights of light for farmers to gather in their crops at the height of harvest. Every month, the nights leading up to a full Moon bring more light to the evening.

Our sleeping patterns are controlled by our natural circadian rhythms— the day and night cycles driven by Earth orbiting the Sun. But there are also circalunar rhythms, which are tied to lunar cycles. Certainly, some animals will respond to both a circadian rhythm and a lunar clock.