Monkeys discovered to use complex grammatical structures in their language

Friday, January 15, 2016 by: David Gutierrez, staff writer
Tags: monkeys, complex language, animal intelligence

---

(NaturalNews) Monkeys have a much more complex linguistic ability than had previously been thought and are able to make use of grammatical structures such as roots and suffixes, according to a study conducted by researchers from France's National Center for Scientific Research and New York University, and published in the journal Linguistics and Philosophy in December 2014.

The study, which focused on the alarm calls used to indicate various predators, also found that the same species of monkey living in widely separated regions applied different meanings to the same words.

"Our findings show that Campbell's monkeys have a distinction between roots and suffixes, and that their combination allows the monkeys to describe both the nature of a threat and its degree of danger," lead author Philippe Schlenker said.

Monkeys have dialects, grammar

The study was conducted on populations of Campbell's monkeys living in the Tai Forest in Ivory Coast and on Tiwai Island in Sierra Leone. Part of the reason these populations were selected is that they must deal with different predators; while the Tai Forest monkeys are menaced by both eagles and leopards, leopards are absent from Tiwai Island.

The researchers used recorded eagle shrieks and leopard growls to provoke the monkeys into making alarm calls, then transcribed and analyzed those alarm calls using methods from human linguistics. Their analysis allowed them to confirm a hypothesis previously suggested by primatologists: that the monkeys use different roots and suffixes to indicate different types and levels of threat.

For example, the noise hok is used to indicate "aerial threat," usually an eagle. When combined with the suffix -oo, the call becomes hok-oo, meaning "less serious aerial threat."

At the Tai Forest, the sound krak is used to mean "leopard." At Tiwai Island, which has no leopards, the same sound instead is a more general call meaning "danger," and could refer to either aerial or ground-based threats.

The researchers used human linguistic theory to attempt to explain how this variation in Campbell's monkey dialects has come about. The concept of "implicatures" suggests that the existence of a similar word can lead to a refinement in the meaning of the original word. For example, certain is a more definite term than possible. Because the word certain exists, the word possible comes to imply "possible, but not certain." Thus, if a person says, "it's possible he's at home," the implication is, "but it's not certain."

The authors suggest therefore that krak always means "general warning." In Tai, where there are more types of predator, the monkeys have come to use the sound hok to mean "aerial threat" and the suffix -oo to mean "weak." Thus, using simply the sound krak implies a "threat that is not 'hok' (aerial) or 'krak-oo' (a minor threat)." In other words, krak comes to mean "serious ground-based threat," such as a leopard.

The researchers believe that there is great potential in continuing to apply linguistic principles developed in humans to the study of animal communication.

Uncovering the complexities of animal language

Recent studies have also reinforced that even much less intelligent animals are able to convey relatively sophisticated information with their vocalizations. For example, a study conducted by researchers from the University of Nottingham and Queen Mary University of London and published in Applied Animal Behaviour Science in December 2014 found that cows and their calves used specific, individualized calls to communicate. No two cows used the same call.

Furthermore, cows were able to communicate distance with their calls, using different tones to summon their calves depending on whether they were in sight or not. Calves' calls also indicated their sex.

Sources for this article include:

http://www.nyu.edu

http://link.springer.com

http://www.qmul.ac.uk