Research suggests that among the main factors affecting right-handedness are genes associated with left-right body asymmetry. Another contributing factor may be environmental influence through societal bias.Continue Reading
Although dyslexia and handedness are not related, researchers studying dyslexia found that a gene identified as PCSK6 also influenced handedness. Further research established that this gene does not work in isolation, but a network of genes contribute towards a propensity to left or right-handedness. These genes are also associated with the compartmentalization of the brain having to do with language ability. For most people, language ability is controlled by the left side of the brain and motor skills, such as handedness, are controlled by the right side. However, in left-handed people, this division of labor in the brain seems to be reversed.
Bias in the surrounding social environment can be a significant factor in the percentage of a population that is right-handed. Some repressive societies have a higher percentage of right-handed people than more open societies, but this is due to suppression of left-handedness rather than natural right-handedness. For instance, children are forced to use their right hand for eating and writing in a number of Asian countries, including Japan, Taiwan, India and Indonesia. Many cultures have disparaging and negative connotations to left-handedness as an inherent part of their languages. Additionally, most tools are fashioned for right-handed use, discouraging use of the left hand, even if it might otherwise be more comfortable.Learn more about Biology