Why Is 13 Unlucky? The History of a Superstition, and Numerology

Key takeaways

• Fear of 13 has a name: triskaidekaphobia, a term first used by American psychiatrist Isador Coriat in 1910.

• The "Friday + 13" pairing isn't attested before the 19th century. Commonly cited "historical" explanations (the Templars, the Last Supper) are late or uncertain.

• 13 isn't unlucky everywhere: in Spain and Greece, Tuesday the 13th is the feared day, and in Italy, 13 is often lucky (17 is the feared number).

• In numerology, 13 reduces to 4 and is a karmic debt number linked to effort, not bad luck.

A Younger Superstition Than You'd Think

Friday and the number 13 each have old superstitions, but no document links them before the 19th century. Early traces include an 1834 French play in which a character says he was born on Friday, December 13, the source of all his misfortunes, and a biography of the composer Rossini, who considered both Fridays and 13 unlucky.

In the early 20th century, Thomas W. Lawson's 1907 novel Friday, the Thirteenth, in which a broker exploits the superstition to cause a Wall Street panic, helped popularize it.

Commonly Cited Explanations

• The arrest of the Knights Templar, ordered by Philip IV of France and carried out on Friday, October 13, 1307, is a historical fact. But its link to the superstition was made long after the fact and isn't agreed upon.

• The Last Supper, with 13 guests including Judas: this connection appears in English-language sources from the 1890s. The Bible doesn't say in what order the apostles sat.

In other words, the superstition probably predates its justifications.

13 in Modern Life

• Missing floors: in 2002, elevator maker Otis estimated that 85% of buildings with its elevators and at least 13 floors had no floor numbered 13.

• Apollo 13: launched on April 11, 1970 at 13:13 Houston time, the mission suffered an oxygen tank explosion on April 13. The crew returned safely on April 17. The story fed the myth, but the accident had an identified technical cause.

• Frequency: every year has at least one Friday the 13th and at most three.

A Lucky Number Elsewhere

13 doesn't have the same reputation everywhere. In Spain, Spanish-speaking Latin America and Greece, Tuesday the 13th is the feared day. In Italy, 13 is often considered lucky, and 17 is the feared number. In France, the national lottery even runs special draws on Fridays the 13th: the superstition cuts both ways.

13 in Numerology

In numerology, 13 reduces to 4 (1 + 3). It's one of the four karmic debt numbers, linked to a lesson in effort and consistency, unrelated to bad luck. In the tarot, arcanum XIII (usually called Death) traditionally symbolizes transformation rather than an ending.

• Karmic debt 13

• Born on the 13th

Frequently asked questions