One tenth of the human population is left-handed, with some countries having more left-handed people than others. Less-developed countries appear to have a more even mix of left- and right-handed people, whereas advanced countries such as Japan have less than one tenth of their population as left-handed. But why are some people left-handed? Is it all to do with the country you are born in? Is it genetics, nature or nurture? Which things about lefties are myths and which are facts?
Can Left-Handedness Be Predicted?
Some say left-handedness can be predicted by the position of the child in the womb, but there are many times when this prediction model breaks down. In fact, the predictive model used is only marginally better than guessing, which suggests the position in the womb is only a possible indicator or stimulating factor and is not actually a predominant factor in what makes a person left- or right-handed.
Is It Genetic?
Just like the position in the womb, there are some people that make convincing arguments that show genetics may be an influencer, but it is not a determining factor or a reliably predictive factor (just like the position in the womb). This has been proven by the fact that identical twins with identical DNA may be right- or left-handed. Even with triplets, there may be one or two that are left-handed and the other one or two that are right handed — which throws out most arguments that being left-handed is genetic.
There are some that say the left- or right-handedness of your parents is an influencing factor, with two right-handed parents only having left-handed children 10% of the time. However, if two right-handed parents give up their baby at birth and hand it off to a left-handed couple, then the child is only 10% likely to be right-handed, which proves genetics has nothing to do with it.
People Used To Be Left- And Right-Handed In Equal Portions
We appear to have had left-handed people for generations. In fact, there is a varied amount of evidence that suggests that left-handed people have been around for over 500,000 years — but that is not really the issue. What is the issue is that these days, being left-handed is a negative thing, but in the past it was normal. Furthermore, before being right-handed was considered ideal, people were an even mix of right- and left-handed.
Swords And The Left-Hand Side Of The Road
Back in the days when horses were a main mode of transportation, people traveled on the left side of a road. That meant that when people passed them on horses, they would be on their right hand side. It becomes common practice to fight with your sword in your right hand because that is where the most likely attack would come from. People learned to hold their shield with their left hand and their sword with their right hand so that they may fight as they pass each other. People also saluted with their right hand for a similar reason, because it helped to expose their face (if they were wearing head amour), and showed that their right hand was free of weapons. Children were encouraged to be right-handed so that they may hold their sword with their right hand.
The Pen Is Mightier Than The Sword
When people became more advanced and learn to write on paper, they discovered that writing with their right hand was easier than writing with their left. Writing with their left hand would cover what was being written and would smudge the ink on the page. Ergo, children were encouraged to be right-handed so that they may learn more easily and write without hindrance.
The Mouse Is In The House
Even computers are built for right-handed people. It is common for the mouse to be on the right side of the keyboard and for the index finger of the right hand to click the left mouse button as opposed to the middle finger of the left hand. Keyboards are also set up with number pads on the right instead of the left, which favors right-handed people once again.
Children Copy Their Parents
The idea that many children must be born right-handed is a myth. The reason so many children become right-handed is that they watch their parents and copy them. They see their parents doing things whilst predominantly using their right hand and so they copy them. For example, if a child picks up a spoon with the same hand as his or her parent, then the child may copy the finger placement on the spoon. This cannot be done if the child picks up the spoon with the other hand because the position of the fingers and the palm of the hand would be all wrong and the child would struggle to copy the parent.
So, next time you are left wondering why a child seems to prefer the left or right hand, try taking a look at the adults around them.