Scientists have suggested that more than choice, it is the brain that decides which hand-right or left-a person preferably uses to perform various tasks.
In the new study, scientists stated that when a Southpaw shakes hands, his left eye and the right portion of his brain are working hard to process the other individual. The research helps to explain why hand and limb preferences exist across numerous species.
The predisposition, as it turns out, are tied to ocular dominance, or the tendency to prefer visual input from one eye over the other, reports Discovery News.
Ocular dominance, in turn, is driven by cerebral lateralization, which refers to how information processing is divided and coordinated between the brain's left and right hemispheres.
"At this stage we have no reason to think that left- or right-brained animals are superior or analyze information differently, except that it's the mirror image," said co-author Culum Brown.
Brown of the Macquarie University, and colleague Maria Magat studied the phenomenon in Australian parrots. These birds, like humans, have a tendency to use either their right or left limb more than the other.
The researchers recorded the eye and foot preferences of the parrots while the birds investigated small pieces of fruit and brightly colored wooden blocks. The majority of the birds showed a clear tendency to investigate the objects using either their left or right eye.
This eye preference was found to directly correspond to the foot that each parrot used to manipulate the food or block. If one of the birds focused on the fruit with its right eye, for example, then it would tend to use its right foot to grasp and move around the food. This provides a better view in front of the preferred eye.
A similar course of action likely happens in humans. As infants, we don't know that we are destined to prefer one hand over the other. Experience determines which hand works best and is the most comfortable to use, setting into place a more permanent practice.
The findings were published in the journal Royal Society Biology Letters.