科学美国人60秒:Triskaidekaphobia Plays Role in Paraskevidekatriaphobia

It’s Friday the 13^th. [Dirty Harry:] “You’ve gotta ask yourself a question: ‘Do I feel lucky?’” If you don’t, you could be suffering from triskaidekaphobia. That’s a fear of the number 13. Napoleon, Herbert Hoover, and FDR are well-documented triskaidekaphobics. But why do folks think 13 is unlucky? Particularly when it falls on a Friday, as it will three times this year?
 
The University of Delaware’s Thomas Fernsler is known as Dr. 13. He’s an expert on the number’s bad reputation, which may date back to Biblical times. After all, the 13^th guest at the Last Supper was Judas. And you know how that worked out for Jesus, who was crucified on Friday.
 
Other factoids from Fernsler:
 
The first person to die in a car accident was killed in New York City on September the 13^th in 1899, although that was a Wednesday. And the ill-fated flight of Apollo the 13^th launched at 13:13 central standard time on April 11^th 1970. And the numerals in the date 4/11/70 add up to 13! As long as you don’t include the 19 in 1970. Hey, sometimes superstition can be hard work. 
 
Today, some tall buildings lack a 13^th floor. Well, they have a 13^th floor, but they call it the 14^th floor. Because the purveyors of bad luck are apparently easily fooled.
 
Meanwhile, over in France, panicky Parisian party-throwers can even hire a quatorziéme, a professional 14^th guest.
 
Like Judas, Mark Twain was allegedly once poised to be the 13^th guest at a dinner party. A superstitious friend warned the very rational Twain not to go. But Twain went. “It was bad luck,” he later remarked. “They only had food for 12.”
 
—Karen Hopkin
 
(The above text is a transcript of this podcast)