Today I found out why the number four is considered to be unlucky in some East Asian cultures (mainland China, Japan, Korea,  and Taiwan,  among others).

In the Chinese culture, whether a number is considered auspicious or not typically depends on whether the number’s name sounds similar to other words with positive or negative meanings or connotations. With respect to the number four, the reason for this common Asian phobia is that the word for the number “four” (四 [sì]) sounds similar to the word for “death” (死 亡 [sĭwáng] ). This same thing holds true for many forms of spoken Chinese, Sino-Japanese and Sino-Korean. All these Asian cultures share significant historical and cultural ties particularly with the Chinese. Hence, why numbers and objects which have names that are homophones for words “death” and “suffering” are typically considered unlucky in these cultures.

Bonus Facts:

• Because of the somewhat common fear of the word four, you may not see a fourth floor in an elevator or a hospital room that ends with “four” in China. In the extreme case, some residential buildings in Hong Kong all floor numbers with “four” are left out.
• Fear of the number four is known as tetraphobia.
• In the early 2000s Alfa Romeo had to change a name for a new model 144 car in Singapore because people were afraid to buy it. For similar reasons, Nokia does not release any phone models that begin with the number “four”.
• In Japan, “forty nine” is considered to be an especially unlucky number because it sounds similar to the phrase which means “pain until death”.
• Beijing’s traffic management bureau has stopped issuing car license plates with number “four”.
• On the flip-side, the numbers six, eight, and nine are believed to be lucky in many Asian countries. In different Chinese languages, the number name for “six” means “fluid”, “happiness” or “blessings”. The word for “eight” sounds similar to words meaning “prosper”, “wealth” and “fortune”. The number name for “nine” has long been associated with the Emperor of China and similar to the word for “long lasting”. This is also why “nine” is often used in many Asian weddings.
• Triskaidekaphobia is fear of the number “thirteen”. This superstition is common in Judeo-Christian tradition and is often related to a specific fear of Friday the 13th.
• “Seventeen” is believed to be an unlucky number in Italy because when written in Roman digits (XVII) that could be rearranged to “VIXI” which in Latin can be an euphemism for “I am dead”.