Righties and lefties – an old story which causes so many argues between people. Why this distinction exists at all? If is it so, why are lefties so rare? Are they mentally ill? And what about ambidexterity? The questions go on and on. Righties make the majority of the human population, approximately 90 percents. This fact separates us from the other primates. Among many asked question in history on this topic, the one prevailed: why are most of us right-handed? Scientists think they maybe found the reason. They found it in the most unexpected source.
Brain Lateralisation: Left Or Right?
Handedness is in correlation with the lateralization of brain function. As we all know, the brain has two hemispheres: left and right. Both have their own functional specializations. The left hemisphere controls speech, language, writing, logic, maths and science. The right side controls music, art, creativity, perception, emotions, and genius. Handedness tends to settle around four years of life. After then it remains a persistent characteristic throughout our life. What determinate which hand will predominate? Well, there is a lot of theories about that, especially when we speak about lefties, including genetics, prenatal hormonal imbalances, early exposure to ultrasounds and so on. One is for sure: handedness is a complex trait that appears to be influenced by multiple factors.
We develop performances that are characteristic for the hand we use. So, if we are a rightie, our left hemisphere is dominant. That means right handed are have higher abilities in mathematics, logical thinking and organizing, memorizing, computing and technical information processing. Left handed have right hemisphere dominant, which makes them more creative, artistic, emotive, musical. The rarest type is ambidexterity. Ambidextrous people can do any task equally well with either hand.
The Fossil Record Might Reveal Why Are Most Of Us Right-Handed
Scientists discovered fossil record at Olduvai Gorge in the Serengeti Plain of Homo habilis old around 1.8 million years. They noticed numerous striations on the front side of the teeth. As the most of the stratiations were right-slanting, the scientist thinks that those marks were made by right hand.
This fossil record represents the earliest evidence of right-handedness. This also means that humans began to develop preferences to the right-handedness 1.8 million years ago. Thanks to that, people could master stone tool making and communication skills, which were very important for a prehistoric man. Probably these facts have made the righties majority in the human population.
