If you're left-handed, you might feel at times that the world isn't designed with you in mind - and there's a reason for that. Apparently only 10 per cent of the population is left-handed, which leads us to questioning why?
Most people will have what's called a dominant hand. It's the hand you can write with and tend to prefer to use when completing day-to-day tasks, due to it being stronger and having more dexterity (fine motor skills and coordination of the small muscles). Your dominant hand is usually determined at around 18 months old.
For 90 per cent of the population, that's their right hand, while less than 10 per cent of people are left-handed. Even fewer are what's called 'ambidextrous', meaning both their hands are equally as strong and flexible.
What causes a person to be left-handed?
It's a bit of a mystery which scientists have a few theories about. It was once believed that handedness was linked to which hemisphere in the brain was dominant. But that one was soon dismissed because if you had a dominant side of the brain, other things that side of the brain is responsible for would also be affected.
While a straightforward genetic link hasn't been found, the following theories have been reported over the years as to why some people turn out to be left-handed:
- Genes - it could simply be a case of inheriting left-handed genetics from your parents. Of course, it's also down to environmental factors and reinforcement.
- Sex - a slightly higher amount of males than females are left-handed, therefore scientists believe that testosterone could have an influence on left-handedness.
- Foetal development - Some scientists believe that handedness actually develops in the womb and that the environmental factors such as hormones during pregnancy could have a role to play.
- Modelling - no, we're not talking about strutting your stuff down the catwalk. It's believed that children copy things from their parents, including which hand they use. But this doesn't explain why right-handed parents have a left-handed child.
- Brain damage - a small percentage of scientists believe in a controversial theory that all humans are meant to be right-handed, but some type of brain damage early in life causes left-handedness. If you're left-handed and reading this, don't be alarmed. There is no hard evidence for this theory.
- Adjustment - In some cases, people who have sustained an injury might have started out right-handed, but due to the need to adjust to an injury, they may start to use their left hand as their dominant hand.
And while one study suggests that left-handed people are likely to be smarter, another says that left-handed people are more likely to be alcoholics? We're not sure how accurate that one it.
Scientists once believed that a right-handed person had dominance on the entire right side of their body: their right eye, ear and foot - and vice versa for left-handed people.
But over the years, we've discovered that handedness isn't as cut-and-dry as that. For instance, some people might be right-handed but have a dominant left foot. Others might write with their right hand, but eat in a left-handed way.
So unfortunately, there isn't one solid explanation for why some people are left-handed. Everybody is unique, which is why it's so difficult for scientists to pin down one theory.
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What's more, left-handedness might be a struggle at times, but there are also some advantages that come with being such a unique human being. For example, it's been suggested that sports people who are left-handed tend to have an advantage over their right-handed opponents.
Featured Image Credit: Unsplash/Kelly SikkemaTopics: Science