Left-handed people ‘might be better at verbal tasks’, scientists claim

People who are left-handed are more likely to be better at verbal tasks than those who are right-handed, a new study has claimed.

Scientists from the University of Oxford recently investigated the correlation between handedness, language areas of the brain and neuropsychiatric diseases.

Published in neurology journal Brain, the researchers used data from the UK Biobank to analyse the genomes of approximately 400,000 people, just under a tenth of which were left-handed.

While the link between handedness and genetics has been explored in the past, the exact genes which are linked to being left-handed or right-handed have not previously been determined.

Thanks to their large cohort of participants, the researchers were able to identify four genetic regions which they claim are linked to being left-handed.

"Around 90 per cent of people are right-handed, and this has been the case for at least 10,000 years," said Dr Akira Wiberg, a medical research council fellow at the University of Oxford.

"Many researchers have studied the biological basis of handedness, but using large datasets from UK Biobank has allowed us to shed considerably more light on the processes leading to left-handedness."

Dr Wiberg continued, stating that "in left-handed participants, the language areas of the left and right sides of the brain communicate with each other in a more co-ordinated way".

"This raises the intriguing possibility for future research that left-handers might have an advantage when it comes to performing verbal tasks," the medical researcher added.

However, Dr Wiberg added that "not all left-handers will be similar", as this conclusion was drawn from "averages over very large numbers of people".

Professor Gwenaëlle Douaud, from the Wellcome Centre for Integrative Neuroimaging at the University of Oxford, commented on the researchers' discovery that a person's handedness may be determined prior to their birth.

"Many animals show left-right asymmetry in their development, such as snail shells coiling to the left or right, and this is driven by genes for cell scaffolding, what we call the 'cytoskeleton'," the professor said.

"For the first time in humans, we have been able to establish that these handedness-associated cytoskeletal differences are actually visible in the brain.

"We know from other animals, such as snails and frogs, that these effects are caused by very early genetically-guided events, so this raises the tantalising possibility that the hallmarks of the future development of handedness start appearing in the brain in the womb."

According to the study, the genetic regions associated with being left-handed may be linked to a lower risk of developing Parkinson's disease, and a higher risk of being diagnosed with schizophrenia.

However, the researchers stated that this link was only discovered among a small difference of people, and that further research is needed on the topic.