NEW STUDY ON ‘LEFTIES’
Study finds left handedness is likely learned, not inherited
IN SAD news for Toowoomba’s left-handers, the QIMR Berghofer Medical Research Institute has released results of a study that proves they are not genetically gifted with greater levels of creativity or insight.
In fact, the study showed genetics plays only a small part in determining if someone is left or right-handed.
The study was the largest of its kind in the world and looked at genetic data from more than 1.7 million people.
It was led by a team of researchers that included University of Queensland professor David Evans.
“For more complex traits, they are normally determined half by genetics and half by environmental factors, but handedness is a very weird one,” he said.
“We found only about 20 per cent of the variance is due to genetics.”
The study identified 41 genetic variants that influence left-handedness and seven that influence ambidexterity in the hope that they shed light on how our brains operate.
“Why people are left-handed is intrinsically interesting but also relates to laterality in the brain,” Prof Evans said.
“Complex functions like language also show laterality.
“The study may give us clues as to why these cognitive processes show laterality.”
The fact that left-handedness is a trait people learn more than one they acquired at birth may be behind the increased number of lefties in recent decades.
“There is a fair degree of plasticity in the brain and people can train themself to use their right hand even if they have predisposition to be lefthanded,” Prof Evans said.
“Historically, the frequency of left-handed people in the population was a lot lower.
“It was seen as an undesirable trait, as the work of the devil or that sort thing.”
Guitarist Jai Tennant is one Toowoomba resident who, until the study was released, thought he was special.
He and his sister are lefties, born to right-handed parents.
He picked up his first guitar when he was four years old and knew instantly that he was destined to play left-handed.
“I really just taught myself how to do it,” he said.
“The only struggle I have is in trying to find a left-handed guitar to buy, but that is the struggle of every left-handed musician.”
His current guitar is a lefthand variant of a 1962 Fender Stratocaster reissue.
Using the mirror image of a right-hand guitar means Mr Tennant can collide with his bandmates on stage.
“I try to stay tucked away on the side,” he said.
The joint QIMR Berghofer Medical Research Institute and UQ study drew on data from 32 cohorts from the International Handedness Consortium, 23andMe and the UK Biobank.