Chimpanzees can combine calls to communicate new meaning

Oliver Lamb, Deputy Editor, outlines the recent discovery that chimpanzees may be smarter than we thought

ASTUDY published in Nature

Communications this month has confirmed that chimpanzees combine calls to create new meanings — a feature of human language known as syntax whose evolutionary origins remain unclear.

Chimpanzees, who are humans’ closest living relatives, have long been known to communicate vocally: for example, they produce ‘alarm-huus’ when surprised and ‘waa-barks’ to recruit other chimpanzees when hunting. Previous behavioural observations suggested that chimpanzees combine these calls to recruit others when needing to cooperate in response to a threat. For the first time this has been verified experimentally.

Researchers from the Universities of Zürich and Warwick showed model snakes to chimpanzees in Uganda, elic- iting the call combination. When the researchers played back the combination sound, as well as the alarm-huu and waa-bark, the chimpanzees responded more strongly to the combination than to either call individually. gests that the phenomenon may be older than previously thought. Townsend said, “Humans and chimpanzees last shared a common ancestor approximately six million years ago. Our data therefore indicates that the capacity to combine meaningful vocalisations is potentially at least six million years old, if not older.”

Simon Townsend, a Zürich professor and Warwick associate professor, said the result “suggests listening chimpanzees really are combining the meaning of the individual calls.”

The possibility that syntax did not first emerge in the human lineage sug-

Indeed, the ability to create new meanings by combining sounds may have preceded language, although more research, ideally involving other great ape species, is needed to confirm this.