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A morbid, irrational fear of Friday the 13th. Therapist Dr. Donald Dossey, whose specialty is treating people with irrational fears, coined the term. He claims that when you can pronounce the word you are cured.
If you base your belief on media attention, superstition about Friday the 13th might be the number one superstition in America today. It appears, however, that only about 10% of us believe that Friday the 13th is an unlucky day (Zusne and Jones 1989, p. 244, put the number at 7%; Vyse 2000, p. 18, cites a 1990 Gallup poll that put the number at 9%, and a 2000 survey by American Demographics put it at 13%).
Friday may be considered unlucky because Christ is thought to have been crucified on a Friday, which was execution day among the Romans. Yet, Christians don't call it Bad Friday. Friday was also Hangman's Day in Britain. Some even think that Friday was the day God threw Adam and Eve out of the garden of Eden, which is unlikely since the concept of Friday hadn't been invented yet.
Is Friday the 13th a particularly unlucky day? It could be...if you believe it is. Some prophecies are self-fulfilling