September 6, 2019 - 11:37 AMT
Genes linked to left-handedness found in new study

Being a leftie has a genetic component, is linked to better verbal skills and is associated with a lower risk of Parkinson’s disease, according to a new study published in the journal Brain, The Guardian reports.

The study is a fascinating one, using thousands of brain scans and hundreds of thousands of sequenced genomes to look for associations between genes, brains and hands. It found that, in left-handers, the left and right hemispheres had stronger links in the regions associated with language, which could correlate with greater language ability.

It also found “significant positive correlation” between left-handedness and mental health outcomes such as sensitivity, having “fed-up feelings” and being a “worrier”. Look, I’m no scientist, but that feels extremely real.

Left-handedness runs in families and identical twins are more likely to have the same hand dominant than are fraternal twins and siblings. This implies that the genes do have some influence, but are not the whole story.

Previous studies have suggested left-handedness is about 25% heritable, with the other 75% of the variation accounted for by environmental factors – although what those factors are remains elusive.

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