Left Handed - Why I Break Can Openers

Being a lefty myself I’ve always been interested in this subject, but there isn’t really a lot of information online or in science journals. There are lots of theories, some more solid than others, but all are still a little flimsy or not very researched.

Only 7 to 10 percent of the population is left handed, with left handedness being more prevalent in males than females. Left side dominance is also more frequent in people with neurological disorders such as epilepsy, autism, downs syndrome and dyslexia.

Evidence of people being left handed can be seen in cave paintings about 10,000 years old, where they would blow paint at their hand placed against the wall to make a silhouette of their recessive hand. As the dominant one is used to flick the paint, therefore most would be of the left hand, only a few being of the right hand. It was also found recently that the percentage of left handed people in the general population hasn’t changed much.

It is thought that combinations of genetic and environmental factors determine the dominant hand:

A team of scientists at OxfordUniversity found that the gene LRRTM1 may play a key role in controlling which parts of the brain control specific functions like speech, emotions and language. They believe that this gene is involved in whether someone is left or right handed.

The brain is set up asymmetrically. In right handed people the left side of the brain controls speech, language and the movement of their right side of their body with the right side controlling emotions, where as in left handed people the opposite is often true. The researchers believe that this gene is responsible for the flip.

They also believe that people with LRRTM1 gene may have an increased risk of schizophrenia, a condition which is often linked to unusual balances of brain function, this could also explain why people with neurological disorders are more frequently left handed than other people.

The other theory is that environmental factor on the developing foetal brain in the womb can determine the dominant hand. The Geschwind theory suggests that increased levels of testosterone on a developing brain before birth can cause left handedness as testosterone suppresses the growth of the left hemisphere causing more neurons to migrate to the right hemispheres. The more developed right hemisphere is then better suited to function as the language and handedness centers. Therefore the fetus is more likely to be left handed as the right hemisphere controls the left side of the body.

This theory also ties into the fact that people with disorders like dyslexia, stuttering and learning disorders are more frequently left handed as testosterone has been linked to these disorders.

There is a lot of stigma attached to being left handed. Even the bible has a dig; God says “Set the sheep on his right hand, and the goats on the left . . . (saying) unto them on the left hand 'Depart from me, ye cursed, into everlasting fire.” Left handed children were punished in schools and forced to use their right hand, a black cat crossing your path from left to right is good luck, but if a black cat crosses your path from right to left it is considered back luck, going over to the dark side and all that. Even the word left is derogatory. In most languages the work left or left handed is derived from the word sinister. Also saying such as ‘Two left feet’ meaning that someone is clumsy comes from the fact that left handers are often awkward in a generally right hand orientated world.

Being a lefty I know the hardships that come with it. Right handers just don’t seem to understand the problems, the usually small, but very annoying problems;

One of the best examples of my left handedness being very inconvenient is when my mum kept noticing that all of our can openers kept breaking; she was very confused until she saw me using a can opener in apparently the most awkward way. I was breaking every new can opener she bought. I was banned from opening cans from then on. She had to buy me an electric one when I went off to university!

Most lefthanders are ambidextrous; scientists don’t know whether this is because some vestiges of movement control is still in the left hemisphere or it is just something left handers have to do to be able to cope.

I believe that it is mostly to cope, when I was small my primary school didn’t have any left handed scissors so I had to learn how to cut with my right, I can no longer use left handed scissors. I also use right handed computer key boards and mouse, but there are still some things like right handed knives (see figure to explain what I mean) which I just can’t use at all, always almost cutting off my fingers.

To help left handed people like myself, more and more shops are cropping up to supply us with weird and wonderful wrong way round things like scissors (if you can still use them), left handed binders and notepads, non smudge pens and many more. But there are some products out there for left handed people which I just think are pretty useless though; left handed mugs, (so you can see the image on the mug) left handed clocks and watches, (they just look wrong) left handed wallets. (I just don’t get those)

Though, with all of the left handed stuff I have, it is funny to watch right handed people try to use them and get really confused when they don’t work. I just stand there and laugh.