New Study Reveals How Humans Became Right-Handed

According to a new study led by Dr Gillian Forrester of the University of Sussex, a predominance to be right-handed is not a uniquely human trait but one shared by great apes.

The study, published in the journal Behavioural Brain Research, analyzed hand actions directed towards either objects or individuals in chimpanzees, gorillas and children, and found that all three species are right-handed for actions to objects, but not for actions directed to individuals.

The results support a theory that human right-handedness is a trait developed through tool use that was inherited from an ancestor common to both humans and great apes. The findings challenge a widely held view that right-handed dominance in humans was a species-unique trait linked to the emergence of language.

“Humans have been tool users for 2.5 million years, while the current view is that language only emerged one hundred thousand years ago,” Dr Forrester said. “Our findings provide the first non-invasive results from naturalistic behavior, suggesting that language emerged as a consequence of left hemisphere brain regions that were already evolved to process regular sequences of actions. The structure found in language may have developed from pre-existing brain processes adapted from experience with tool-use.”