On the island of Java, in Indonesia, the silvery gibbon, an endangered primate, lives in the rainforests. In a behavior that’s unusual for a primate, the silvery gibbon sings: It can vocalize long, complicated songs, using 14 different note types, that signal territory and send messages to potential mates and family.
Far from being a mere curiosity, the silvery gibbon may hold clues to the development of language in humans. In a newly published paper, two MIT professors assert that by re-examining contemporary human language, we can see indications of how human communication could have evolved from the systems underlying the older communication modes of birds and other primates.
“How did human language arise? It’s far enough in the past that we can’t just go back and figure it out directly,” says linguist Shigeru Miyagawa, the Kochi-Manjiro Professor of Japanese Language and Culture at MIT. “The best we can do is come up with a theory that is broadly compatible with what we know about human language and other similar systems in nature.” Specifically, Miyagawa and his co-authors think that some apparently infinite qualities of modern human language, when reanalyzed, actually display the finite qualities of languages of other animals — meaning that human communication is more similar to that of other animals than we generally realized.
“Yes, human language is unique, but if you take it apart in the right way, the two parts we identify are in fact of a finite state,” Miyagawa says. “Those two components have antecedents in the animal world. According to our hypothesis, they came together uniquely in human language.”