Why am I right-handed and not left-handed? Why is she left-handed? Ordinary yet thinkable! Such questions might sound absurd but they definitely halt us for a second and pose curiosity.
Several studies and models have been proposed to explain this mystery of handedness, a few of them favored nature to be responsible over nurture while the rest supported the external factors and overlooked genetics. Unfortunately none of them explained the factual reason.
After tons of studies and researches, three people: Hopkins, Kavaklioglu and McManus, despite their individual researches agreed on a common notion which points that handedness is influenced by many different factors, which include; genes, culture, implicit learning and external factors that affect the birth, before and after.
Earlier, a model had been proposed by a psychologist Chris McManus called Dextral/Chance model, which supported the notion that handedness relies on genetics and it is controlled by a single gene in two forms dextral (D) or chance (C), but later on, a paper published in the Journal of Heredity explained that handedness is not just controlled by one gene instead many genes are involved in it. Surprisingly, about 25% of the variation in handedness is genetic based which eventually fails to support this claim.
Another study claimed that the culture controls selection of handedness; the surroundings of where you are born or raised makes you choose your hand type. It is believed that children are more susceptible to imprint their parents and Tulya Kavaklioglu, a graduate student at the Max Planck Institute for Psycholinguistics-who is studying the connections between handedness, language and genetics, supported this claim of cultural influence over selection of handedness. She referred to a study conducted in 1981, on the prevalence of left-handed Australians. But Hopkins, a Professor of Neurosciences at the Georgia State University said that culture doesn’t totally explain it.
For now, there is no empirical definition for indicating what decides handedness and so far studies have failed to exude one legit factor that controls it. Though, the number of lefties is less than the righties but it is still unclear as to why people are more biased towards using their one hand over other.