Researchers compare primate vocalizations

The utterances of Old World monkeys, some of our primate cousins, may be more sophisticated than previously realized — but even so, they display constraints that reinforce the singularity of human language, according to a new study co-authored by an MIT linguist. 

The study reinterprets evidence about primate language and concludes that Old World monkeys can combine two items in a language sequence. And yet, their ability to combine items together seems to stop at two. The monkeys are not able to recombine language items in the same open-ended manner as humans, whose languages generate an infinite variety of sequences.

The paper, “Systems underlying human and Old World monkey communications: One, two, or infinite,” was recently published in the journal Frontiers in Psychology. The authors are Miyagawa, who is a professor of linguistics at MIT; and Esther Clarke, an expert in primate vocalization who is a member of the Behavior, Ecology, and Evolution Research (BEER) Center at Durham University in the U.K.

To conduct the study, Miyagawa and Clarke re-evaluated recordings of Old World monkeys, a family of primates with over 100 species, including baboons, macaques, and the probiscis monkey.

The language of some of these species has been studied fairly extensively. Research starting in the 1960s, for example, established that vervet monkeys have specific calls when they see leopards, eagles, and snakes, all of which requires different kinds of evasive action. Similarly, tamarin monkeys have one alarm call to warn of aerial predators and one to warn of ground-based predators.

Read the full publication here:

Systems Underlying Human and Old World Monkey Communication