Why are some people left-handed?

          Most of the people in the world do most of their work with the help of their right hands, but four per cent of the world population is left-handed. If we go through the history of mankind we find that many of the great men of the world have been left-handed. The world famous sculptors Leonardo da Vinci and Michelangelo were both left-handed. Parents of the left-handed children usually feel worried about this habit. They make efforts to correct it. But psychologists are of the opinion that if a child is a left-hander, he should not be forced to change this habit.

           Now the question arises: why are some people left-handers? If we examine the constitution of the body a little minutely, we will notice that our body is not fully symmetrical. There is a little asymmetry between the left and right side of the body. Generally right side of the body is slightly heavier than the left side. Our brain has also right and left parts. Even the functions of these parts are somewhat different. Usually the left half of the brain is ‘predominant’ over the right half. In such cases, the nerves from the brain cross over at the level of the neck and go to the right side of the body. Such persons are right-handed. Most people of the world fall under this category. But in those cases where right half of the brain is predominant than the left, nerves coming out of the brain pass onto the left parts of the body. Such people perform all their functions with their left hands. That is why some children write and even eat food with left hand.

          Now the question arises: why are the left-handers in such a minority in comparison to the right-handers? Scientists have not been able to solve this riddle till now. Since the number of right-handers is so large, the door handles, locks, screw-drivers, motor cars, musical instruments all are designed keeping in view the convenience of the right-handers. Even buttons are fixed on our clothes on the right side for this reason only. The left-handed people experience some difficulty in handling all these but, of course, they somehow manage them.