Nearly 142 years after Charles Darwin wrote that the sounds uttered by birds offer in several respects the nearest analogy to language, MIT researchers have now found that birdsong closely resembles human speech.
Researchers from Massachusetts Institute of Technology, along with a scholar from the University of Tokyo, say that Darwin was right when he wrote in “The Descent of Man” (1871) contemplating how humans learnt to speak language, could have had its origins in singing.
The balance of evidence, researchers believe, suggests that human language is a grafting of two communication forms found elsewhere in the animal kingdom: first, the elaborate songs of birds, and second, the more utilitarian, information-bearing types of expression seen in a diversity of other animals.
“It’s this adventitious combination that triggered human language,” co-author and linguistics professor in MIT’s Department of Linguistics and Philosophy, Shigeru Miyagawa said.
The idea builds upon Miyagawa’s conclusion, detailed in his previous work, that there are two “layers” in all human languages: an “expression” layer, which involves the changeable organisation of sentences, and a “lexical” layer, which relates to the core content of a sentence.
The study authors say that birdsong closely resembles the expression layer of human sentences — whereas the communicative waggles of bees, or the short, audible messages of primates, are more like the lexical layer. At some point, between 50,000 and 80,000 years ago, humans may have merged these two types of expression into a uniquely sophisticated form of language.