Chimpanzees have language

I’ve read in several places that language is the last uniquely human characteristic.  Well, it turns out chimps communicate with a language of gestures: Researchers Translate the Meaning of Over 60 Gestures Used by Chimps.

In the first systematic study of a non-human primate language, scientists from St. Andrew’s University have deciphered the meaning of 66 wild chimpanzee sign language gestures. Ranging from flirting requests to grooming instructions, the gestures may reveal how language evolves.

The study, which now appears in Current Biology, shows that wild chimpanzees use at least 66 gestures, such as arm raises, ground slaps, and foot stomps, to intentionally communicate 19 meanings. This dictionary, or “lexicon,” was compiled by researchers Catherine Hobaiter and and Richard Byrne after observing over 80 wild chimps in the rainforests of Uganda, and then examining over 4,500 individual cases to decipher true (i.e. non-playful) meanings for the various gestures; the researchers isolated non-playful uses because in play, gestures are not always used with their ‘real’ meaning.

As fascinating as this is, I can’t help observing that this form of communication is still profoundly simple.  Chimps are our closest cousins and this is still pretty far from symbolic communication.

That said, some of the reports hint that there may be more going on in the communication.  This snippet from the Wired article on this study caught my attention.

One limitation of the researchers’ approach is that it can only identify gestures that provoke an action. Those that convey something more subtle — two chimps talking about the weather, for example, or reminiscing about the good old days — can’t now be interpreted. Whether such conversations occur is an open question.

“I have the impression that there were some meanings we couldn’t capture,” Hobaiter said. Sometimes, she recalled, a chimpanzee would gesture to another, then appear satisfied, though nothing else seemed to happen. Said Hobaiter, “I’d love to know what was going on!”

Of course, the danger with this apparently more nuanced communication is that the human observers could just be projecting their own mental state and intentions unto their subjects, something many of us do with our pets.