The human ability to communicate through language is truly astounding. It begs the question of why no other animal species can communicate as humans can, and the study of language, alongside psychology, can point us towards evidence why other animals might not possess similar linguistic capabilities. Comparisons with apes have provided promising theories of language, namely an innate, genetically inherited ability to speak. However, this would seem to dismiss important environmental factors that determine the languages we speak, such as culture or geography, as merely final details in a pre-existing capacity for language.
Language in apes (Koko the gorilla)
One successful approach to language investigation compares humans with their closest relatives, apes. We share 96% of our DNA sequence with chimpanzees (Broad Institute Communications, 2005), with gorillas close behind, and yet cannot communicate at all with these great species.
The closest believed example is Koko the gorilla, who was taught American Sign Language at the Gorilla Foundation in San Francisco (The Legacy of Koko the Gorilla, MacDonald, James, 2018). She impressed with what seemed to be an ability to respond to cues using signs and even express feelings of her own without prompts. Koko was even able to teach her companion, Michael ways to communicate with signs, some of which were unique to the gorillas, and had not been taught to Koko by a human.
However, numerous studies have unfortunately disproved the theory that Koko had learnt to use and adapt Sign Language to express everything she wished to communicate. Most notable in this was the work of Herbert Terrace, with his experiments with the amusingly named Nim Chimpsky, a chimpanzee to whom Terrace also taught American Sign Language (Ape-Language Controversy Flares Up, Marx, Jean, 1980). These experiments served to show that these apes were simply very talented in replication, and sadly their use of signs was not much different to a dog learning to roll on command for a treat. While this equally constitutes an instance of language usage, it lacks the structure and definition needed to allow extended, elaborate communication between species.
Comparing chimpanzees and children
(Do both learn the same way, and could they learn language in the same way?)
Michael Tomasello, a psychologist currently based at Duke University, leads the way in comparative research between language and cognition in children and apes. Cognition refers to the process of acquiring knowledge and understanding through mental processes, such as thought, or sensory experiences. Tomasello’s work puts forward important reasons why chimpanzees and gorillas cannot learn a language in the way humans do, as well as indicating important features of child language acquisition.
Child language acquisition is a topic in the field of linguistics and psychology, as well as philosophy of language, investigating the processes by which children first learn how to speak a language. There are still many attempted explanations for the remarkable way very young children become capable of speech and writing.
While working at the Yerkes Primate Center, Tomasello conducted experiments on the reactions of two-year old children and chimpanzees to using tools. One key distinction found by the team was the method of learning. Children were able to replicate the use of tools in different contexts, while the chimpanzees studied and emulated the tool use in every case.
The chimps would understand using a hammer to put a nail in a wall but couldn’t use the back of a hammer to remove a nail already in the wall. This showed that children are attentive to behaviour and social aspects of tool usage, whereas the chimps only understand the cause-and-effect process behind tool functions. (Processes of social learning in the tool use of chimpanzees and human children, Nagell K, Olguin RS, Tomasello M, 1993)
(Humans are the only species who can understand sharing and communicating emotions)
This result points towards a key feature of children’s language missing in apes: shared intentionality. Intentionality refers to a theory on how we represent the world around us in our minds – it can almost be understood as language in the mind, before it is expressed. Shared intentionality conveys the idea that, whereas primates may be sociable animals, with emotions and the ability to communicate them, they do not have the cognitive skills for exchanging knowledge in cultural groups and partaking in collaborative activities with shared goals (Shared Intentionality, Tomasello M, Carpenter M, 2006). Only humans have overcome the notion of ‘cognition for competition’ (A Natural History of Human Thinking, Tomasello M, 2014) biologically ingrained in animal species. At this point, Tomasello’s work helps to bridge a gap between psychology and philosophy, and the practical and theoretical approaches to understanding a language.
The Language Gene (?)
Tomasello’s work helped discover these differences between language in humans and chimps, but could not fully account for the reasons why they occurred. Then came the work of Myrna Gopnik (1990), and scientists thought they had found the solution. Gopnik studied a family with three generations of developmental verbal dyspraxia (DVD), a learning disability affecting their understanding of grammatical constructions. Gopnik attributed this to a failed expression of a gene later designated as the Forkhead Box P-2 gene, shortened to FOXP2. Investigations of FOXP2 showed that humans were the only species with the exact DNA sequence containing this “language gene”, and chimpanzees shared in most of the genetic expression, except for two crucial changes in the gene sequence, that might explain the results of Tomasello’s experiments (Evolution of a Single Gene Linked to Language, Smith, K, 2009).
Not only did FOXP2 account for why only humans could speak a language, but it aligned with a hugely popular theory in linguistics, Noam Chomsky’s popular theory of ‘universal grammar’, clarified in his Language and Mind (Language and Mind, Chomsky, N, 1968) lecture-series turned into a published work. If our genetic composition accounted for disabilities in language, that would mean that there was a ‘language instinct’ (The Language Instinct, Pinker, S, 1994) and the miracle of language is an innate ability that can be explained by our DNA.
However, the direct link between FOXP2 and language expression was later disproved (No Evidence for Recent Selection at FOXP2 among Diverse Human Populations, Atkinson EG, Audesse AJ, Palacios JA, Bobo DM, Webb AE, Ramachandran S, Henn BM, 2018). On reflection, a gene coding for language seems to dismiss the influence of environmental factors on language. As Tomasello points out (Constructing a Language: a usage-based theory of language acquisition, Tomasello, M, 2003), whereas other species are perfectly capable of communicating between each other, at least 80% of the human population would be unable to understand the English of this article. Instead of futile attempts to create a generative grammatical understanding behind language, Tomasello puts forward a usage-based theory of language.
The alternative to innate grammar and language
A usage-based theory of language operates on the idea that language is gradually built up over the course of repetition and constant attempted use of words and phrases to communicate. This accounts for contextual factors that change language development, such as culture, region, and education. Meanwhile Noam Chomsky’s ‘universal grammar’ struggles to underpin all languages, despite its claim of universality. A usage-based theory also accounts for the differences observed between language-use in children and adults, as repeated experience allows children to progress from the weaker structures that lead to their grammatical mistakes into fully correct usage in adulthood.
Investigations on the nature of language and our first acquisition are very important to understanding how we think, and perceive the world, as well as how we communicate amongst ourselves and create shared goals in a way that other animals cannot. Theories on the origin of language are still emerging, and while further investigation into the field of the “language gene” has not been rejected (Human Genetics: The Evolving Story of FOXP2, Fisher, S, 2019), currently the usage-based approaches to understanding language provide a more comprehensive analysis of language and cognition in humans.