If you were afraid of the number 13 (as in Friday the 13th), you'd suffer from . . .
If you're afraid to get near a swimming pool, you might be suffering from . . .
Somebody with necrophobia would have no business applying for a job as . . .
Friday the 13th is an unlucky day in much of Western Europe, North America, and Australia. Many people avoid travel and avoid signing contracts on Friday the 13th. Floors in tall buildings often skip from 12 to 14. And while the superstition is believed to be fading, it nonetheless has deep roots in both Christian and pagan culture.
Many Christians have long believed that Friday was unlucky because it was the day of the week when Jesus was crucified. The number 13 was believed to bring bad luck because there were 13 people at The Last Supper. Since there were 12 tribes of Israel, that number was considered lucky.
Thirteen was also a sinister number in Norse mythology. Loki, one of the most evil of the Norse gods, went uninvited to a party for 12 at Valhalla, a banquet hall of the gods. As a result, he caused the death of Balder, the god of light, joy, and reconciliation. Loki tricked Balder's blind brother, Hod, into throwing a sprig of mistletoe at Balder's chest. Since mistletoe was the only thing on Earth fatal to Balder, the beloved god fell dead.
During the Middle Ages, the superstition against Friday the 13th grew. On Friday, October 13, 1307, King Philip IV of France ordered the arrests of Jaques de Molay, Grand Master of the Knights Templars and sixty of his senior knights in Paris. Thousands of others were arrested elsewhere in the country. After employing torture techniques to compel the Templars to "confess" to wrongdoing, most were eventually executed and sympathizers of the Templars condemned Friday the 13th as an evil day. Over time a large body of literature and folk wisdom have reinforced the belief. In the 18th century, the HMS Friday was launched on Friday the 13th. It was never heard from again. Since then, ships are not usually launched on that date. (Click here for other mysterious ship disappearances.)
It is considered especially unlucky to have 13 people at the table during a meal, such as in Agatha Christie's mystery novel, Thirteen at Dinner. During the 1880s, a men's group that felt superstition was an unhealthy influence on public life held Thirteen Club dinners. Those diners would have doubtless deplored Triskaidekaphobia, which is a fear of the number 13. They would also have looked askance at Triskaidekamania, which is an excessive enthusiasm for the number 13. (Take our Phobia Quiz (part I) on Triskaidekaphobia and other scary phobias.)