Some people claim that left-handedness has nothing to do with genetics, but this is highly untrue. If you have a left-handed parent, there is a solid chance you or a sibling will be left-handed. If you have two parents that are lefties, it is almost certainly their offspring(s) will be too. Although this has been studied for hundreds of years, we are just now coming to the conclusion that there is a biological, genetic cause for people being left-handed.
[Image via Lukassek/Shutterstock.com]Some felt that hand preference was caused psychologically by the parent, but this was proven to be untrue. We now know two alleles are the cause of hand preference. Scientists found that the D-Gene and C-Gene, the two alleles, were responsible for everything. Those born with the D-Gene end up right-handed a majority of the time. Those born with the C-Gene, far less common, will have a random hand preference. This allows them to literally pick their left in a 50/50 split.