World estimates suggest that anywhere between 75% and 90% of people favor their right hands. Why? The question has baffled scientists for years. Several scientific and cultural explanations exist to explain why most people use their right hands. Handedness may be genetic. Though, scientists have not yet identified the exact processes involved. Handedness may also be the product of social and cultural pressures. There may even be evidence for the ancient anthropological origins of right versus left. The fundamental question remains. Why are most people right-handed?
Brain Development and Cognition
Homo habilis, an ancestor to modern humans, lived 1.8 million years ago. Their reputation, and their very name, comes from their ingenuity. Homo habilis possessed the dexterity to form and use tools. Scientists studying the fossil record believe development of tools and handedness share a common connection. When observing subjects engaged in building, experts found that activity occurred most strongly in the brain’s left hemisphere. This hemisphere is responsible for execution and planning. It is also no secret that the brain’s hemispheres control motor functions on opposite sides of the body. Given the relationship, many have made a correlation. Right-handedness came naturally to the ancestors of modern humans. Tools and survival skills activated the left side of the brain. Thus, the brain favored the right side of the body for execution.
Another theory related to our ancestors does not deal with tools at all. Rather, it pertains to the development of language. As they became more advanced, the ancestors of modern humans developed the ability to communicate using language. Again, scientists point to a “left-hemisphere, right-handed” hypothesis. Skills related to language all rely on the left side of the brain. As a refined spoken language came into wider use, so did use of the right hand.
Bias Against the Left-Hand
Throughout history, many cultural and educational institutions discouraged left-handedness. Teachers forced left-handed children to use their right hands. Students in several Catholic schools recount times when they had their left hands flogged with a yardstick. Teachers would hit some students in the head with a copy of the Bible if caught writing with the left hand. To a lesser extent, the practice continues today. Teachers discourage students from using their left hands. The effect this practice has on children lasts a lifetime. Forced handedness results in learning and speech disorders, dyslexia, and stuttering.
Places throughout Asia force children to use the right hand because of things like socioeconomic background and manners. One study found that families from poorer backgrounds tended to force children to use the right hand. The Western world is home to just as many similar trends.
Cultures around the world associate left-handedness with a number of undesirable characteristics. These include bad luck, rudeness, weakness, and sin. Even Satan himself gets dragged into the argument between right and left-handedness. Many religions, Judeo-Christian and otherwise, depict the devil as left-handed.
Another likely culprit is modern tool creation. Left-handed people have had to adapt to living in a right-handed world. Companies design everything from composition notebooks to scissors to firearms with right-handed users in mind. Left-handed alternatives now exist for many tools, though. Yet, for things like machinery and weapons, alternatives are expensive. Not having access to these other options can even be life-threatening.
Scientists, anthropologists, and experts have worked for years. They’ve wrestled with the questions of handedness. There is still no broad consensus. Theories rely on a great deal of variables impossible to test. They cannot very well travel back in time to study the brain development of humanity’s ancestors in real time. Answering the question, “why are most people right-handed” does not come with a concise response. Whether left-handed, right-handed, or ambidextrous, nobody is wrong-handed.Right-Handed