Babies and bonobo apes share common 'language', say scientists
Human babies and bonobos - apes that are said to be our closest primate cousins - share a common "language", scientists have revealed.
Both are able to make communicative sounds that can be adapted to a range of different emotional states and situations.
The ability may be evidence of a lingual "missing link" marking the evolutionary transition from animal calls to human speech, research suggests.
Most animal vocalisations are tied to specific contexts linked to emotional states, for instance to warn about predators or display aggression.
But British and Swiss researchers found that wild bonobos in Africa produced high-pitched "peep" calls in a wide variety of situations, including feeding, travelling, resting, showing aggression, alarm-sounding, nesting and grooming.
Understanding the meaning of the calls required making intelligent inferences based on the contexts in which they were made.
Likewise, human babies produce "protophone" sounds independent of emotional state before they start using recognisable words.
Lead scientist Dr Zanna Clay, from the University of Birmingham's School of Psychology, said: "When I studied the bonobos in their native setting in Congo, I was struck by how frequent their peeps were, and how many different contexts they produce them in.
"It became apparent that because we couldn't always differentiate between peeps, we needed to understand the context to get to the root of their communication.
"It appears that the more we look, the more similarity we find between animals and humans."
Bonobos look very like chimpanzees and belong to the same genus, or animal "family", but are actually a separate species.
In the wild they are far less aggressive than chimpanzees and dominated by females, who form tight bonds. They are the most vocal of great apes.
Captive bonobos have been observed making tools from branches and rocks much like "stone age" humans.
The new research is reported in the online journal PeerJ.