The origins of language have long been a mystery, but mounting evidence hints that our unique linguistic abilities could have evolved from gestural communication in our ancestors. Such gesturing may also explain why most people are right-handed.
Researchers at the Yerkes National Primate Research Center recently examined captive chimpanzees and found that most of them predominantly used their right hand when communicating with one another–for example, when greeting another chimp by extending an arm. The animals did not show this hand preference for noncommunicative actions, such as wiping their noses. Such lateralized hand use suggests that chimpanzees have a system in their left brain hemisphere that is coupled to the production of communicative gestures, says study author William Hopkins. The same cerebral hemisphere is host to most language functions in humans, which hints that an ancestral gestural system could have been the precursor for language, he says.