Unlucky Thirteen

All numbers over twelve were regarded as insignificant, with the exception of the number thirteen and forty. One of the reasons why thirteen has been regarded as an unlucky number throughout the ages may be that it is one number more than twelve, which is universally regarded as a number of completeness. As the number thirteen crosses the unity of the number twelve it assumed the connotation of dangerously exceeding the ‘proper limits’ and hence of starting on a new and uncertain course. 

The number thirteen’s ill-omened associations in superstition are universal and the number has been regarded as fraught with misfortune and ill luck since antiquity. The prejudice against this number is of obscure origin and already existed in ancient Greek and Roman times. For example, the Romans considered it unlucky for thirteen people to be in a room together. In pre-Christian civilisations, as far apart as India and Italy, the number thirteen was considered a bad omen.

Christian religious circles ascribe the origin of all ominous beliefs related to the number thirteen, to the Last Supper, attended by Christ and the twelve disciples. But this does not account for the dislike the ancient Greeks, Romans and other cultures had towards the number long before the spread of Christianity. The thirteenth day of the month has for centuries held ominous associations, but when the thirteenth day of the month also falls on a Friday the negative omens linked with both concepts are compounded. (See Chapter IV – Unlucky Friday the 13th) 

In modern times, the fear of the number thirteen, known as ‘tridecaphobia’ is probably still the most common of all superstitions and is still prevalent. A dinner party with thirteen guests is inadvisable; furthermore the number is often avoided on office doors and by some hotels and airlines. There are even buildings without a thirteenth floor, the numbers instead jumping from twelve to fourteen. 

When we speak of a baker’s dozen, we mean thirteen of something. The term is believed to be derived from a custom, dating from the Middle Ages, of baking an extra loaf of bread with each batch of twelve. The extra loaf was meant to compensate for any shrinkage and consequent loss in mass.