Through genetic analysis of 1.75 million people, scientists at the QIMR Berghofer Medical Research Institute and the University of Queensland have brought us one step closer to why people turn out to be lefties.

Researchers identified 48 genetic markers that influence whether a person is right-handed, left-handed, or ambidextrous (equally capable with both hands). 41 of these markers were associated with leftiness and 7 of them were with ambidexterity.

Prof. Sarah Medland explains, "Handedness is one of those things where both genetics and environment play a large role and what we've been able to do is advance the knowledge quite a bit further in the genetics side." She then explains that each of these small variations play a minuscule role on their own, but when they add up, they then begin to have a significant impact.