By: Helice Stratton (Bugle Team)
Edited by: Emma Keoy (Bugle Team)
It goes without saying that the media have a habit of exaggerating the findings of scientific papers. If a journal publishes evidence that starlings may be able to statistically analyse segments of speech—similar to how human infants begin segmenting words (Gentner, Fenn, Margoliash et al. 2006)—an article will likely surface claiming in bold, capital letters: “STARLINGS CAN LEARN TO SPEAK??”. It is understandable we’re so excited to find evidence that animals have some kind of language though—aside from lending credence to the Disney films we watched growing up. Logically, language must have evolved somehow, but we don’t yet know how. Did our mouths, throats and brains evolve to accommodate it? Or was it just adapted from pre-existing physical and cognitive systems? Finding buildings blocks for language in other species will give us a deeper understanding of how our own language instinct evolved.
The barks and meows we’re familiar with are just simple calls: they don’t communicate anything and don’t require any concept of meaning. But some animals don’t just call: they sing. Aside from the obvious birdsong and whale-song, dolphins, gibbons and even some mice (Holy and Guo, 2005) sing. Birdsong is to date the most well-studied form of song however, because identifying their songs and how others of their species react to them does not require tracking them as they travel at high speeds across large stretches of ocean.
What exactly does it mean for an animal to “sing” though? In technical terms, a song is an ordered sequence of individual sounds separated by gaps of silence (Suzuki et al 2006). At first glance individual birdsongs look promisingly like human sentences. The individual sounds combine into “syllables”—don’t get too excited about this though. Human syllables have requirements about the order of their consonants and vowels, as well as constraints on which can carry stress depending on where in the word they are. Avian “syllables” sadly have none of this complexity and are hence syllables in name only.
A sequence of syllables will combine into a “motif” or “phrase”, and these make up the song (Doupe and Kuhl 1999). But this is where the similarities to human speech ends. Every bird has a vocabulary of motifs—they learn these as infants and won’t create new ones. How many they have varies by species; zebra finches only have one while canaries can have around 300 (Yip 2016). But motifs hold no meaning on their own—only the complete song communicates anything, and that’s generally based around territory or mating; pairs of birds will sing “duets” in which one will pick up the song directly after the first one stops, usually for the same purposes (Langmore 1998). In this way, songs are more like individual words—a sequence of meaningless sound that have meaning together—than sentences.
Presumably, our best chance of finding something even more familiar is in our closest relatives: chimps. The lovingly named Nim Chimpsky is one of the most famous attempts at teaching a chimp American Sign Language, though various other studies have attempted similar—one experimenter even taught a chimp called Ai to recognise and understand the numbers one to nine (Matsuzawa 1985). Though chimps can learn to produce nouns and verbs—though not orally—they are unable to put strings of more than two or three together, the conceptual meaning behind the words. Many of these studies tend to have significant methodological flaws as well, so one should be sceptical when reading them. However, chimps do appear to have a Theory of Mind: understanding of the thought processes and knowledge of others, at a similar level to a human infant. This is one of the basic higher cognitive functions required for language and something currently not found in other species.
Though it has been argued that trying to identify language systems in other species is impossible when we know so little about our own, the search is still ongoing. As I’ve said, we don’t know as much about dolphin and whale communication as we’d like to, and new discoveries are still being made about other species. Annoyingly it’s very difficult to tell whether we’re seeing actual cognitive functions or if it’s just wishful thinking. But there are traces of what could, under the right conditions, develop into part of a language—though these traces are spread out across many species. Needless to say, we still have yet to find where our language came from and how we evolved such a highly complex ability to essentially transmit our thoughts to other members of our species.
Clarke E., Reichard U. and Zuberbu K. (2006). The Syntax and Meaning of Wild Gibbon Songs. PLoS One, vol. 1, no. 1, pp. 1-10
Doupe A. and Kuhl P. (1999). Birdsong and Human Speech: on Themes and Mechanisms. Annual Review of Neuroscience, vol. 22, pp. 567-631
Gentner T., Fenn K., Margoliash D. and Nusbaum H. (2006). Recursive syntactic pattern learning by songbirds. Nature, vol. 440, no. 7088, pp. 1204-1207
Holy T. and Guo Z. (2005). Ultrasonic Songs of Male Mice. PLoS Biol, vol. 3, no. 12, pp. 2177-2186
Langmore N. E. (1998). Functions of duet and solo songs of female birds. Trends in Ecology and Evolution, vol. 13, no. 4, pp. 136-140
Matsuzawa T. (1985). Use of numbers by a chimpanzee. Nature, vol. 315, pp. 57-59
Yip, M. (2016). Human and avian phonology. PowerPoint Presentation. PLIN7310: Animal Communication and Human Language, University College London