It’s curious how some people have genetic differences to one another, don’t you think? For instance, many of us have different colored eyes to each other. And, while the majority of people are right-handed, a vast amount of people in the world are actually left-handed. Yes, you also get those annoyingly perfect people who are ambidextrous and can use either hand equally well!
But our focus is predominantly on left-handed people, and, specifically, why there are left-handers. Now, when we were in school there were always jokes, or supposed truths circulating about left-handed people – for instance, all left-handers have poor handwriting. But, these were just hearsay, and urban myths; here is why we have left-handers, and some characteristics about them.
Now, you probably think that people being left-handed has something to do with the brain, right? We know that the brain is separated into two different halves. Right-side brain is responsible for performing tasks to do with creativity – it also controls the left side of the body. While left-side brain controls the right and is responsible for logic and science. So we can naturally assume this correlates with left and right-handed people, right? Wrong!
It’s actually the spinal cord
The brain has little bearing on whether a person is right-handed or left-handed, it’s actually the spinal cord that determines this. Which hand you will favor is a factor that is decided before you are born – specifically from the eighth week of pregnancy. It’s to do with gene activity, and leads to you becoming left or right-handed while still in the womb, before the brain and spinal cord is even fully developed! Movement of the baby’s limbs starts in the brain – a signal is sent to the spinal cord, but the way this signal is expressed is asymmetrical, leaving a baby to favor one hand and arm over the other – either left or right.
Why are there so few left-handers?
Around 10% of people in the world are thought to be left-handed. This is a small percentage, but still a huge amount of people. But, there must be a reason why lefties are so rare in this day and age. Yes, genetics play a role, but there could also be social factors that played a part as well. In fact, it’s thought that we have naturally genetically evolved to be right-handed to be more of a united community, so anyone who went against the majority was at a disadvantage. This could explain why there is such a disproportionate amount of right handers to left.
We don’t know for sure
We don’t actually know for sure exactly why it is that people are left-handed. There are many possible reasons, and it’s most likely to be a cross between genetics and environmental factors affecting the mother during pregnancy. It’s also incredibly hard to predict whether a child is going to be right-handed or left-handed when they are born, which makes it tougher to add them to research. But it is clear that the neurological differences between left-handed and right-handed people are so small it’s almost incidental.
So, as you can see, there are only very slight differences between left-handers and right-handers. It’s interesting that it’s not the brain that determines this, but the spine, and that it’s so difficult to determine what a person is going to be. After years of persecution back in the day, being left-handed is seen as pretty uneventful these days.