Although not all scientists agree on the answer, many believe that most people’s brains develop more on one side than on the other. And since the left side of your brain controls the muscles on the right side of your body, and the right side of your brain controls the muscles on the left side of your body, this would influence the muscles in your hands as well.
Therefore, if the left side of your brain is more developed, then you are right landed. If the right side of your brain is more developed, then you are left-handed. If, however, your brain is equally developed on both sides, you are ambidextrous, you can use one hand as well as the other.
In a right-handed person, the right hand is usually larger than the left because its muscles have developed more!
