that old devil moon

We've all heard the phrase, "it must be a full moon out there", to
describe strange or unfortunate happenings. There is still the
prevalent superstition that the full moon has an effect on humans,
causing erratic behaviors, and such disturbances as emergency room
calls and traffic accidents. Belief in the “lunar lunacy effect,” or
“Transylvania effect,” as it is sometimes called, persisted in Europe
through the Middle Ages, when humans were widely reputed to
transmogrify into werewolves or vampires during a full moon.
(Heh-heh, just call me "Villow". I've come to vipe your vindows.)

One theory is that the full moon’s ­supposed effects on behavior arise
from its influence on water. The moon's gravitational pull does effect
the tides. The human body is about 80 percent water, so perhaps the
moon works its mischievous magic by somehow disrupting the
alignment of water molecules in the nervous system. I don't know.

Extensive studies over the years have proven there to be no
correlation between the moon and mental disturbance. So, why
then, is the belief in the "lunar effect" still prevalent today? After
all, isn't this where we get the words lunar, loony and lunatic?
I'm sure folklore and Hollywood have a lot to do with it. Scary
things tend to happen in movies, with that big full moon inducing
madness and mayhem.

Personally, I happen to know someone whose behavior does become
rather erratic around the full moon. There are also many sensible
people, including police officers and emergency room staff, who see a
lot of full moon CCFCCP, and continue to believe that old devil moon
certainly can stir up his share of pesky trouble.