Like most superstitions, fear of Friday the 13th has a shadowy history. Folklorists usually trace it to the story of the Last Supper, where Jesus was the 13th guest. The next day, Friday, he was crucified.
But the belief has other roots. In Nordic folklore, 13 is considered an unlucky number. According to Nordic myth, 12 good gods were having a party, which was crashed by a thirteenth, the evil god Loki. In the ensuing brawl, Baldar, the most popular god, was killed.
"There is a record of people in the Mediterranean basin 2500 years ago being afraid of the number 13," says Michael Salovesh, an anthropologist at Northern Illinois University. Salovesh suspects that fear of 13 may be the result of an obscure cultural rivalry. An expert on Meso-American culture, he points out that the Mayans believed that 13 was a lucky number. (Maybe that explains the disappearance of their civilization.) Their calendar had a 13-day week, and their heaven had 13 levels. Salovesh speculates that the widespread Western superstition against 13 was somehow a response to this. "It's a numbers game," he says. "Your lucky number has got to win against their unlucky number."
Friday has unlucky associations of its own. Many cultures believe that starting a project on a Friday is bad luck. In medieval Europe, Friday was traditionally Hangman's Day. It is also supposedly the day that Eve tempted Adam with the apple. Witches were believed to meet on Friday.
(Others think Fridays bring good luck. An eastern European Gypsy folk remedy recommends the following to cure a sick child: Tear the child's clothing off, cut the cloth up with scissors, boil it in a new pot, then throw the pieces over the roof. On the following Friday, take the clothes, the pot and the water and bury it at a crossroads. This will cure the child.)
Salovesh has had his own run-in with the date. "Friday the 13th, June 1958," he recalls. "That was the day that my wife and I set out for a trip to backwoods Mexico. It was a horrible trip. We got malaria, hepatitis, and amoebic dysentery. We drove down a mountainside and our brakes went out. We blew up the engine of our car." Salovesh, however, is not superstitious at all. He ascribes his misfortune entirely to coincidence. "I've had a helluva lot of other Friday the 13ths, a couple of hundred at least. But I don't remember any of them, because nothing happened."
Umbrellas were originally used as sunshades by African, Asian, and Mexican royalty. Because umbrellas were connected with the sun, which wa often worshipped, and with use by god-like leaders, it became an object with sacred connotations, and therefore one that should be used carefully.
For centuries, European pagans worshipped trees as powerful gods. Jesus' cross was made of wood.
In many cultures, cats are thought to be supernatural. The ancient Egyptians, for example, worshipped cats. In medieval times cats were associated with witches.
According to Irish folklore, the devil tries to rush into your mouth when you yawn.
Cultures all over the world believe that the nose is a good place for souls to leave the body, or for evil spirits to enter it.
This belief has several origins. The shape made by the ladder, the ground, and the wall, was seen as a version of the Sacred Triangle, a powerful symbol in many ancient cultures. By breaking the continuity of the Triangle, you invite the anger of the Gods. In the Middle Ages, ladders were used for hangings. And in many medieval paintings, a ladder is shown leaning against Jesus' cross.