
Humans get their linguistic functions from the left side of the brain (the left cerebral hemisphere, to use the proper semantics - more to come). But why? How did we begin using this 'hemispheric lateralisation' (told you!); setting us on the road to modern language? A team of American experts claims chimpanzees, our nearest cousins, hold the key.
The group, from Yerkes National Primate Research Centre in Atlanta, Georgia, recently completed a study of 70 chimpanzees over a ten-month time period (published in Elsevier's Cortex, Jan 2010), recording their communicative gestures both towards humans and each other. Specific movements included 'arm threat', 'extended arm' and 'hand-slap', fulfilling social roles like attention-seeking, excitement, threat, reconciliation, grooming, play or aggression.