A new study published by Oxford University has directly linked left handedness and brain formation, on top of already existing studies that show up to forty genes are connected to left handedness. Too bad they didn’t publish this four weeks ago, in time for International Left Handers Day.
Emphases in the text are mine:
Genes associated with left-handedness linked with shape of the brain’s language regions
It was already known that genes have a partial role in determining handedness – studies of twins have estimated that 25% of the variation in handedness can be attributed to genes – but which genes these are had not been established in the general population.
Dr Akira Wiberg, a Medical Research Council fellow at the University of Oxford, who carried out the analyses, said: […] ‘We discovered that, in left-handed participants, the language areas of the left and right sides of the brain communicate with each other in a more coordinated way. This raises the intriguing possibility for future research that left-handers might have an advantage when it comes to performing verbal tasks, but it must be remembered that these differences were only seen as averages over very large numbers of people and not all left-handers will be similar.’
‘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.’
The researchers also found correlations between the genetic regions involved in left-handedness and a very slightly lower chance of having Parkinson’s disease, but a very slightly higher chance of having schizophrenia. However, the researchers stressed that these links only correspond to a very small difference in the actual number of people with these diseases, and are correlational so they do not show cause-and-effect. Studying the genetic links could help to improve understanding of how these serious medical conditions develop.
To my “parents”, to the “teachers” I endured in elementary school, to the abusive nuns in catholic schools, and to all who continue to abuse left handed children by forcing them to use the wrong hand: You were always wrong. You committed wrongs. And how much progress did you inhibit with your ignorance?