Continuity approach
It is undoubtable that humans are not the only species capable of intraspecific communication through ways other than speech: dolphins produce complex patterns of clicks and whistles, birds have specific chirps, chimpanzees use facial expressions and gestures. All of these processes are conveying meaning to other members of their species, and therefore can be described as communication. The important question to discuss, however, is how it came to be that humans are the only species who can communicate through a complex system of language and speech. This uncertainty of how our language has evolved is an ongoing issue for linguists. There are two main approaches which divide linguists; these are the continuity approach and the discontinuity approach. This essay aims to discuss the continuity approach and critically assess its relevance in the debate of how language has evolved.
The continuity theory of language evolution explains language as having developed from pre-existing animal communication systems over time, while the discontinuity approach states that language as we use it now is too complex to have developed this way, and that there must have been a genetic mutation which brought about language the way we know it. In this essay,’ language’ refers to the way in which we communicate through speech as defined by Hockett’s (1963) design features of displacement, productivity, cultural transmission and duality.
The theory of continuity can be further split into the theory of language having developed through evolution of animal communication or evolution of animal cognition (Ulbaek 1998). The theory of language having evolved from previous animal communication systems is displayed by a continuum as put forward by Hauser, Chomsky and Tecumseh Fitch (2002). We can see through animal behaviour that many species undoubtedly communicate with each other, as mentioned in the introduction, and that they have done for a very long while. Looking back to the time in which dinosaurs existed, researchers have stated that they may have produced closed-mouth vocalisations which they used to communicate. These would have been similar to those used by birds, for example the cooing of a dove (Riede et al., 2016). There is also evidence of other forms of communication being used by dinosaurs, other than vocalisations. For example, they would have used mating rituals which bear resemblance to those of modern birds. Evidence has been found that, similar to modern birds, some male dinosaurs created ‘nests’ to attract females, showing their ability to provide a safe home for off-spring (Lockley, 2016). Examples such as these show us that this is the starting point to communication as we know it now. However, ultimately, as time progressed the existing forms of animal communications, such as the ones previously mentioned, became unsatisfactory for the complex needs of species as they developed. Such as apes for example, who now use advanced body language and facial expressions. For example, an ape pointing the sole of its foot at another ape conveys the meaning “climb onto my back” (Hobaiter and Byrne, 2014). Looking at apes more closely, it can be concluded that apes, along with most other species of animal, do not have the ability for social learning. Social learning is the notion of learning from one another, by imitation and observation (Bandura 1977). This links into the theory of continuity because it provides an explanation for how humans have evolved a communication system much more complex than any other species. This is because as species such as apes are incapable of social learning, they cannot benefit from others’ ideas, or learn from others. This is also true of our ancestors, homo erectus and the Neanderthals. The homo erectus used their clearly advanced intellect to make tools such as hand axes in order to survive. However, evidence from the fossil record shows that the design of these hand axes remained unchanged for around a million years (Pagel, 2011). This clearly shows that they were unable to communicate well enough to share their ideas with each other and therefore discuss and improve the design of their hand axes, because they lacked social learning skills. We know that as humans we are definitely capable of social learning, and so that must have a part to play in our ability to have created our language system. This can be explained by the notion that when our species came to exist, around 200,000 years ago, we must have somehow acquired this skill of social learning. However, having social learning skills but no real means of communication, meant that the issue of ‘visual theft’ arose (Pagel, 2011). This meant that because imitation was possible but discussion and vocal sharing of ideas was not, the notion of imitating and copying was essentially just the stealing of others’ ideas without accreditation. The only solution to this was the development of pre-existing communication systems, such as homo erectus’ gestures or facial expressions, into what we now know as language. This in turn prevented ‘visual theft’ and allowed humans to collaborate, share ideas and cooperate. We can clearly see that this notion supports the idea of language having evolved from previous animal communication systems because it takes into account how our ancestors, homo erectus and the Neanderthals, used communication and not language and how an advancement into language as we know it now was necessary in order to progress as a society and ultimately as a species.
The other idea, however, is that this advancement in our language happened because as natural selection lead to our advanced cognitive skills, we became the only species capable of using such a complex language system. Research into brain sizes of ancestors throughout history clearly shows a development in not only brain size but development of specific areas connected to language. For example, the homo habilis appeared 1.9 million years ago and showed development in the Broca’s area: the region in the frontal hemisphere which is connected to speech production (Hawks, 2017). After this, records of fossil skulls of the homo erectus from 1.8 million years ago show that they had even larger brains, so they likely too had a slightly more developed Broca’s area. By the time our species arose, we had brains even more developed, with a Broca’s area developed to the point where we were able to produce and learn to communicate through speech.
The discontinuity approach denies all the neo-Darwinian concepts put forward by the continuity theorists. As our language system today is so complex, discontinuity theorists believe it cannot be a development of the communication systems mentioned earlier: those which we see in animals, and saw previously in primates. Instead, they suggest that a genetic mutation somewhere along the timeline of human evolution produced the language trait, and natural selection meant that all humans eventually acquired the trait as it was so advantageous. A main supporter of this approach is Noam Chomsky.