Day two of the ‘Blogging from A-Z Challenge’ and I’m struggling with being left handed. I admit it, I’m right handed.
What does this mean? Well, I do many things with my right hand but not everything by a long way. I’m quite happy to open doors or take the top of jam jars with either hand but when it takes a little more finesse, or dexterity, then it is the right hand that automatically volunteers. I don’t have to think about it. I’m right footed as well, not that you would know.
I have assumed that I was born that way, that somehow my right handedness was a product of my genetics but is it? It would seem that things may be a little more complicated. First of all each of us isn’t handed but rather shows a preference for using a particular hand in certain circumstances. That fountain of all knowledge, Wikipedia puts it that handedness is a better (faster or more precise) performance or individual preference for use of a hand. Handedness is not a discrete variable (right or left), but a continuous one that can be expressed at levels between strong left and strong right.
It also turns out that there are other forms of handedness. Being right handed is dead common with as much as ninety per cent of the population showing such a preference (or bias). They are more skilful when using their right hand. The next most common isn’t left handedness as you might think but rather mixed handedness. This is where people use different hands depending upon the task, so you might write with your left but use a hammer with your right for example. Apparently as much as thirty per cent of the population may be this way (I know, the numbers don’t add up)
Left handedness, where people are more skilful when using their left hand accounts for around ten per cent. Apparently it is slightly more common in men than women. Being ambidextrous, that is being skilled equally with both hands is not common at all although it can be learnt though the person will still have a preferred hand. Finally there is ambisinister which is where you are not skilful with either hand.
Back to my question, is my handedness an inherent behaviour or is it learnt? Is it genetic or phenotypic, that is the appearance of an organism resulting from the interaction of the genotype and the environment? The jury is out. There is clear evidence that there is a genetic element but it is obvious that what your parents do and how your friends react has a huge part to play.
The genetic link isn’t a simple one. It certainly doesn’t follow the traditional dominant and recessive gene model. Indeed some scientists dispute that handedness is inherited. Perhaps the link isn’t so clear after all. Charles Darwin was right-handed yet his son was left-handed. Research by John Santrock has shown that birth parents have a greater effect upon the handedness of their adopted children than the adopted parents.
It’s all a bit complicated.