Many cultures see 13 as unlucky, and the fear is called triskaidekaphobia. It is a superstition, not a fact.
Where it comes from
Fear of 13 is triskaidekaphobia. Fear of Friday the 13th is paraskevidekatriaphobia.
Origins
Possibly from the Last Supper, where 13 sat at the table, and Norse myth.
Effects
Buildings often skip a 13th floor. About 80% of high rises omit it.
Evidence
No scientific evidence shows bad luck.
Culture
In Italy, 17 is unlucky. In China, 4.
Cost
Estimates say Friday the 13th costs the US economy about $800 million a year, but this is a rough estimate.
Origins
Fear of the number 13 is called triskaidekaphobia. Explanations include the Last Supper, at which 13 people were present, with Judas as the 13th guest in the Christian tradition, and a Norse myth in which Loki was the 13th guest at a banquet in Valhalla and caused the death of Baldur. Friday the 13th combines this with the fear of Friday.
- Many hotels and buildings skip a 13th floor. Surveys suggest a notable share of high-rises omit it.
- Some airlines skip row 13.
- A 1993 study in the British Medical Journal reported more traffic accidents on Friday the 13th in Surrey, UK, but later analyses disagree.
Cost and evidence
The Stress Management Center and Phobia Institute in North Carolina estimated that US businesses lose 800 to 900 million USD on Friday the 13th because people avoid flying or working, though this estimate is widely cited without strong data. There is no scientific evidence that 13 is unlucky. Meanwhile, 13 is seen as lucky in some cultures, such as in Italy, where 17 is considered unlucky.
Origins
Fear of the number 13 is triskaidekaphobia. Possible origins include the Last Supper with 13 guests, Norse myth of Loki as the 13th guest, and the Knights Templar arrests on Friday 13th, 1307. Many buildings skip the 13th floor.
Cost and evidence
A study cited by the Stress Management Center estimated losses of up to 800 to 900 million USD on Friday the 13th in the US, though the figure is disputed. Studies of accidents show no consistent increase.
Superstition across cultures
In Italy, 17 is considered unlucky, while 13 is lucky in some places. Many hotels and airplanes skip the 13th row. Friday the 13th occurs one to three times per year. In Norse myth, 13 guests at a dinner including Loki led to the death of Balder. In the Bible, 13 people were at the Last Supper.
Statistics
Studies from the Dutch Centre for Insurance Statistics showed fewer accidents on Friday the 13th, possibly because people are more careful. A 1993 BMJ study found traffic volume fell but hospital admissions from road accidents rose in one UK region, though replication is lacking. Triskaidekaphobia affects an estimated 17 to 21 million Americans, according to the Stress Management Center, but such figures are popular estimates.
Based on data from the BMJ and the Encyclopaedia Britannica
