The Next Frontier of Linguistics Is Monkey Chatter

Photo: Mayela Lopez/AFP/Getty Images

Closely related to the question of anthropomorphism — to what degree can we describe animals in human terms? — is the issue of animal speech. Spoken language isn’t just the domain of humans: We know, for instance, that adult birds use baby talk with their young offspring, for instance, and that whales have regional accents (and some scientists suspect that cats do, too).

And in one case, at least, the best way to understand how animals talk to one another may be to borrow tools from the study of human language. Over a series of studies and papers, a team of linguists and primatologists has made the case for a new field they’ve named “primate linguistics,” which the researchers defined on their project’s website as “apply[ing] methods from contemporary linguistics to the analysis of monkey calls.”

By studying a handful of different monkey species in Africa and South America, the researchers have learned that the animals’ calls follow their own set of rules, a system more complicated than just using one sound to convey one meaning. In one paper titled “Monkey Semantics,” for example, the researchers explained that Campbell’s monkeys, a species found in West Africa, “have a distinction between roots (especially hok and krak) and suffixes (-oo), and their combination allows the monkeys to describe both the nature of a threat and its degree of danger. For instance, hok warns of serious aerial threats — usually eagles — whereas hok-oo can be used for a variety of general aerial disturbances; in effect, the suffix -oo serves as a kind of attenuator.” (The research thus far has focused on warning calls, chosen in part because they tend to be louder, and therefore easier to pick out, than other types of vocalizations.)

Much of what the researchers have been able to glean about Campbell’s monkeys so far, as Scientific American has previously reported, is the result of a 2009 trip to two of their natural habitats: Sierra Leone’s Tiwai Island and Ivory Coast’s Taï Forest. “When you really want to understand the meaning of a call, you need a field experiment,” researcher Philippe Schlenker, a linguist at France’s National Center for Scientific Research, told Scientific American. “If you yourself are the trigger, you have much better control over what causes each calling sequence in the first place.” In this case, the triggers were recorded eagle noises on the island and fake leopards in the forest, strategically deployed to frighten the monkeys into making noises for the team to record.

But as Schlenker and his colleagues emphasize on their website, it isn’t so much that they’ve cracked any kind of primate code that will allow us to translate the animals’ chatter (or krak-ed, as Scientific American noted in an A-plus pun); monkey-to-human dictionaries won’t be hitting the market anytime soon. Rather, they’ve laid the groundwork for future study. “Rich data collected by primatologists are ripe for linguistic analysis,” they wrote on the project website, so long as linguists are careful not to overstate the similarities between monkey speech and ours. “People love to think that monkeys have language just like humans do,” they wrote. “In fact, the monkey languages we study have very different (and much simpler) rules than human language.”