Life's Little Mysteries

Why is Friday the 13th Considered Unlucky?

friday the 13th, unlucky 13, folklore
It is not certain where it began, but some believe fear of Friday the 13th started in Biblical times. (Image credit: rtimages | dreamstime)

No one knows for sure what's up with our odd fear of Friday the 13th, so ingrained in pop culture that it has a movie series and one mouthful of a phobia — paraskavedekatriaphobia — in its honor.

Folklorists think the dread goes back at least a few centuries, and may well trace its roots all the way to Biblical times, when the 13th guest at the Last Supper betrayed Jesus and caused his Crucifixion, which was held on a Friday. Whatever the origin, by the late Middle Ages both Friday and the number 13 were considered bearers of misfortune. That potent combo, more than any specific association with the date, is what has deemed Friday the 13th unlucky .

Today it's dismissed as an old superstition but — if given a choice — how many of us would eschew getting married, flying or giving birth on a Friday the 13th? Superstition, indeed.

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Heather Whipps
Heather Whipps writes about history, anthropology and health for Live Science. She received her Diploma of College Studies in Social Sciences from John Abbott College and a Bachelor of Arts in Anthropology from McGill University, both in Quebec. She has hiked with mountain gorillas in Rwanda, and is an avid athlete and watcher of sports, particularly her favorite ice hockey team, the Montreal Canadiens. Oh yeah, she hates papaya.