In the largest study of its kind to date, researchers have identified 48 genetic variants that influence if a person is left-handed, right-handed or ambidextrous.
The research led by QIMR Berghofer Medical Research Institute and The University of Queensland also confirmed that environment plays a far larger part than genes in which hand a person prefers to use.
Co-senior author and head of QIMR Berghofer’s Psychiatric Genetics Group, Professor Sarah Medland said 41 of the identified genetic variants influenced a person’s chances of being left-handed. Seven were associated with ambidexterity, which describes when a person is equally proficient with each hand.
“The 41 genetic variants influencing left-handedness were different to the seven we identified for ambidexterity, and we saw very little correlation between the results for the two traits,” Professor Medland said.
Joint-senior author from The University of Queensland Diamantina Institute, Professor David Evans said the large data set also confirmed that the influence of genetics on handedness was relatively modest.
“The results from our analyses suggested that genetic factors could only account for a small amount of the variation in handedness, whereas environmental factors were likely to play a much more important role. This percentage was similar for ambidexterity, meaning factors such as injuring a hand or training by playing sport or musical instruments are likely to have a strong role in a person’s ability to use both hands equally well.”
The study findings will be published tomorrow in the journal Nature Human Behaviour.