Long considered a harbinger of bad luck, Friday 13th has inspired a late 19th-century secret society, an early
20th -century novel, a horror film franchise and not one but two unwieldy terns---
Paraskavedekatriphobia and Friggatriskaidekaphobia--that describe fear of this supposedly unlucky day.
THE FEAR OF 13
Just like walking under a ledder, crossing paths with a black cat or breaking a mirror, many people hold fast to
the belief that Friday the 13th brings bad luck. Though it's uncertain exactly when this particular tradition
began, negative superstitions have swirled around the the number 13 for centuries.
While Western cultures have historically associated the number 12 with completeness ( there are 12 days of
Christmas, 12 months and zodiac signs, 12 labours of Hercules,
12 gods of Olympus and 12 tribes of Israel just a few examples, it's successor 13 has a long history as a sign of bad luck.
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Fear of the number 13 has earned a psychological term: Triskaidekaphibia.