Barely two generations ago left-handed children were being forced to write with their right hands. Nowadays left-handedness usually only brings good-natured teasing and a difficulty with tools designed by their right-handed oppressors.
However, superstitions about all things lefty go back centuries and can be found in almost every language and culture.
Left in language
The Latin word sinestra, originally meaning left, took on an unfortunate meaning over time and is where we get the English word sinister. A similar pattern is apparent in other languages. For example, in Welsh chwith means left, but also “wrong”. The Swedish word for left – vänster - is related to the word for infidelity, whilst in Chinese the adjective, 左 which means “improper” also means, you guessed it, left.
Left in culture
The left side or left hand is often seen as evil or untrustworthy in religious traditions. Buddhism sees the left path as being the wrong way of life and the right path as being the right way to Nirvana.
The Bible mentions the right hand of the Lord as being special or just, although there are many more references to both right and left hands, where no bias is obvious.
In Islamic society it is seen as wrong to eat with the left hand, which historically was reserved for unclean bodily duties.
The World of Handedness website tells us that “Ancient Mayan and Aztec (Central/South America) rituals use the middle finger of the right hand to first tip into the soil then to the lips in order to bring protection and blessing.”
Tarot cards usually depict the personification of justice holding a sword with his right hand whilst the devil is left-handed.
In sailing, a boat on a starboard tack (with the boat’s right side to windward) has right of way over one on a port tack.
According to Anything Left-Handed, “The Meru people of Kenya believed that the left-hand of their holy man has such evil power that he had to keep it hidden for the safety of others.”
There are a few traditions which favour the left hand side as being lucky, but they’re far outweighed by those which consider it evil.
From the examples above it seems that bias against the left hand is widespread and either very old, or derived from some common factor amongst all people. One possibility for this suspicion or resentment may have been due to the surprising advantages left-handers have in combat. This is apparent in one-on-one sports such as boxing or fencing. I’ve also noticed – anecdotally – a larger than expected percentage of left-handers who are successful in racket sports.
So why should left-handers have an advantage in these situations? Well, as less than 10% of all people are left-handers, most people will be used to competing against right-handers. So a left-hander causes confusion by being unexpectedly stronger and more skilful on their left side. This only works whilst left-handers are a relatively small proportion of the population, if the balance was 50% left-handers, then there would be no advantage. Why the majority of people are right-handed is still open for debate. It may be a simple chance of evolution.
The effect is also apparent in the case of other animals, such as aquatic snails and crabs:
The overwhelming majority of snail species are right-handed — their shells coil clockwise. Dietl studied a species of snail that are lefties, and have shells that coil counter-clockwise.
The left-handed advantage is realized when snails interact with predators of opposite handedness. Some predatory crabs are “righties” — and have a specialized tooth on their right claw that acts like a can opener to crack and peel the snail shells.
So when faced with a “left-handed” shell the crab ends up looking like a left-handed human trying to cut straight with right-handed scissors. Being self-concious about their clumsy feeding the right-handed crabs will often give up, leaving the left handed snail feeling rather smug about its shell design.
I don’t know whether snails and crabs have any superstitions about left or right handedness, but humans certainly do. The suspicion of left-handers may have been because their success seemed somehow sneaky or underhand.
While there are some theories about differences in thought-processes between left and right handers, there’s no evidence I know of to justify the malign superstitions sometimes expressed against lefties. Although I’m right-handed myself, I’m thankful that these superstitions have for the most part been left behind.