Why do most people use their right hand?
Scientists have been studying why most people are right-handed for many years. Although languages and cultures around the world differ, the pattern of right-handedness is the same everywhere. Even animals like chimpanzees and gorillas have a tendency to use one hand more than the other. Researchers at the University of Oxford have brought new information to solve this mystery. According to them, there are two main reasons for human evolution behind most people using their right hands. The first reason is the habit of humans walking upright on two legs. The second reason is that the size of the human brain has gradually increased over time. Scientists collected data on the behavior of 2,025 monkeys and animals from 41 different species and analyzed various factors such as food intake, object use, body size and brain structure. The study, published in the journal PLOS Biology, said that there was not a single reason behind humans becoming right-handed. This happened as a result of multiple evolutionary changes. Human legs are much longer than their hands. This is designed for walking upright on two legs. When humans started walking on two legs, the hands were freed from the work of movement. People started carrying things from a distance with their free hands. Gradually, the use of hands for complex and delicate tasks continued to increase. Thomas A. Puschel, Associate Professor of Evolutionary Anthropology at the University of Oxford, said: "We have tested the major theories of human right-handedness for the first time in a study. Our results suggest that it is associated with upright walking and the development of a large brain. By looking at many species, we are understanding ancient and unique features of humans. Early in evolution, right-handedness was less prevalent among our ancestors. Early species such as Ardipithecus and Australopithecus showed slight signs of right-handedness, similar to that of great apes. Later, this trend became clear with the evolution of other human species. Right-handedness gradually increased among Homo ergaster, Homo erectus and Neanderthals. It took its strongest form in the modern human era." According to scientists, most people tended to use their right hand more when the brain size increased. As the brain size increased, the functions of its two parts became more specialized. The left brain controls the right side of the body. Due to this, the rate of right-handedness spread widely across the entire human population. Not all ancient human species were strongly right-handed. A difference was seen in the case of a special species called Homo floresiensis. They were quite small in size. Among them, the rate of right-handedness was very low. The brain of this species was relatively small. They were used to climbing trees as well as walking upright. Therefore, they were not similar to other human species that came later. The scientists' research is not yet complete. Researchers will look into how human culture has helped maintain the habit of using the right hand. In addition, the mystery of why some people remain left-handed is still unsolved. Research is also underway to determine how the tendency to use the same limb came about in animals such as parrots and kangaroos.
Nature has some strange secrets hidden in the body of every animal. About 90 percent of the people in the world prefer to use their right hand. Such strange behavior is not seen in any other animal. Behind this common habit of our daily life, there is a history of evolution of thousands of years.