2019: Ang Ying Xuan, Valerie Tiong Hui Ling, Wan Muhammad Ariff
1. Introduction and Aims of Discussion
1.1 What is Universal Grammar?
1.2 The Origin of Universal Grammar
1.2.1 Adaptationist
1.2.1.1 The Adaptationist Problem
1.2.2 Non-Adaptationist
1.2.2.1 The Non-Adaptationist Problem
1.2.3 How About Minimalism?
2. Cultural Transmission
2.1 What is Cultural Transmission?
2.2 Effects on Language
3. The Neural and Cognitive Basis of Language
3.1 What Helps Shape Our Language
3.1.1 Constraints from Thought
3.1.2 Pragmatic Constraints
3.1.3 Cognitive Constraints
3.1.4 Biological Constraints
3.1.4.1 Vocal Apparatus
3.1.4.2 Memory
3.2 Universal Human Constraints
4. Problems of Gene-Language Co-evolution
4.1 What is Gene-Language Co-evolution?
4.2 Plausibility of the existence of Gene-Language Co-evolution
4.2.1 Reasons for its improbability
4.2.2 Reasons for its probability
5. Conclusion
1. Introduction and Aims of Discussion
Universal grammar (UG) is one major theory which has garnered much attention in contributing to possible explanations for the origins of our language acquisition ability. It has been and continues to be widely discussed, and many have tried to establish that if it does exist, from where does UG originate. However, as with any discussion, problems with these proposed theories are present too, ultimately leading us to discuss the question of whether the evolution of UG took place, and if not, then what other possibilities exist on the evolution of language, from a biological standpoint.
Hence, we begin by establishing the logical problem of language evolution that stems from the most commonly discussed perspective on UG. Next, we explore other explanations that might provide insight into the evolution of language, such as the cultural transmission of language and the neural and cognitive basis of language. Following this will be a discussion on problems from a biological standpoint of language evolution, before we finally conclude our findings.
Before we can begin to understand the core of the debate, we must first understand some of the discussions about what UG is, and where it might have come from.
1.1 What is universal grammar?
Universal grammar is a theory which proposes humans have inborn facilities relating to language acquisition (Barsky, 2016), composing of a set of subconscious rules which enable us to determine a correct sentence formation. It is based on the idea that specific features of syntactic structure are universal, and indeed, it has been proven that there are 5000 to 6000 languages, in spite of their vastly different grammars, which possess a common set of syntactic rules and principles (Dubuc, n.d.).
As such, it is important to understand that UG encodes universal, though arbitrary to communication, principles of language structure.
1.2 The Origins of Universal Grammar
There exist multiple theories as to how UG might have come about, some discussing it as either having evolved from something, others as an appearance by chance. The particularly major few we will discuss below are the adaptationist and non-adaptationist approaches to evolution of UG in the brain.
1.2.1 Adaptationist
Adaptation is about the natural selection of preferred genes which are the determiners of biological constructions that enhance fitness, with regards to predetermined numbers of possible offspring. A biological structure would be most able to contribute to fitness by fulfilling a function. For instance, the heart is thought to pump blood, the legs to enable movement from one place to another, and UG, to support language acquisition. The better the structures are able to fulfill their function, the more contributive they would be and hence naturally be selected. The adaptationist hence proposes that UG arose from specific brain processes particularly relating to the acquisition of language (Christiansen & Charter, 2008). These processes have evolved overtime, undergoing many cycles of natural selection, through selecting particular random genetic transformations over long periods of time, providing specific humans with a clear advantage in adaptability. However, it remains unconfirmed what the advantage which language provided was, whether in ability for better coordination of hunting parties, danger warnings, or communication between sexual mates (Dubuc, n.d.).
1.2.1.1 The Adaptationist Problem
The problem starts where according to the adaptationist view, as an adaptation to the linguistic environment, universal language properties would eventually become genetically encoded. As such, it is the aspects which are most likely to lead to improved communication which would be positively selected. In other words, the functional aspects of language. For example the compositional character which language posses is a functional aspect, as the ability to express in an infinite number of messages using a finite number of lexical items (Christiansen & Charter, 2008) serves great communicative function.
However, UG, according to Chomsky, is made of linguistic rules which seem largely conceptual and arbitrary, lacking any functional implication. This arbitrariness suggests that however the arbitrary principles are combined, they still remain similarly adjusting to our usage, provided we communicate with similar arbitrary principles in mind.
Hence, there are three main issues with this idea, regarding the dispersion of human populations, language change, and genetic encoding (Chater & Christiansen, 2012). Firstly, there exist many different environmental conditions and scenarios regarding language evolution and the migration of humans, through which diverse language groups would have emerged. These different groups would have adapted accordingly to suit the conditions of their linguistic environment, instead of forming a universal language faculty, and hence they would not adopt the same arbitrary principles across the groups. Secondly, even if we are to consider just a single population, the rate of change of linguistic practices would still be higher than the rate of genetic change, thus natural selection would not be able to catch up, this will be further elaborated on later in section 4.2.1. Thirdly, it is strange that UG would have encoded the arbitrary and abstract aspects of human languages, when natural selection brings about adaptations made to suit the existing environment, and these would be the ability to grasp and internalise the precise features of the early language-like communicative methods created by ancient hominins, not the supposed ability to acquire any of the vast possibilities of languages which no one had ever come across before (Christiansen & Chater, 2008).
1.2.2 Non-Adaptationist
The non-adaptationist’s view is that UG did not come about due to adaptation to an environment, but instead appeared by some variation in chance. For example, as a side-effect of an increase in brain size or still undiscovered physical or biological evolutionary constraints, as hinted at by Chomsky. Non-adaptationists usually view UG to be both extremely elaborate and profoundly distinct from other biological structures. They argue that UG seems to be unlike anything seen before in its attributes and composition, that there is a very low chance of it being a result of natural selection amidst unpredictable mutations.
1.2.2.1 The Non-Adaptationist Problem
The likelihood of accidentally forming a completely operating, and entirely new, biological feature by chance is exceedingly small. Even though tiny genetic modifications result in alterations of extant sophisticated systems, and these alterations can be fairly extensive, the production of new developments is not a possible result, as a gene alone is not able to form a completely new function, from the ground up. The arguments for UG is that UG is both extremely coordinated and complicated, and entirely different from generic cognitive rules. Hence the appearance of a supposed UG requires the creation of a novel, complicated structure and what we have discussed is that the probability of even limited new intricacy appearing by chance is exceedingly low (Christiansen & Charter, 2008).
1.2.3 How About Minimalism?
Unlike previous arguments about the evolution of UG, minimalism views UG from a different perspective of what it might actually consist of and hence inviting new possibilities and insights into the different perspectives regarding language and its evolution. Minimalism views the language faculty as a ‘minute organism’, with limited and basic features (Boeckx, 2006). It depicts the brain’s language ability originating from a multitude of plastic cerebral circuits making up the brain, and it is this plasticity which allows for an innumerable amount of concepts. The brain then continues to correlate sounds and concepts, and the properties of grammar that we abide by would exist as the outcome, or by-products, of how language functions. One of these concepts of minimalism, is recursivity, which is the ability for one clause to be embedded inside another (Dubuc, n.d.). It was thought to have originally developed to help us solve problems such as with numerical computation or social relationships. By linking recursivity with the other motor and perceptual skills required for this utilisation, humans became competent in complex language because of recursivity. And so the evolutionary biologist, Hauser, suggested that the content of UG may be highly limited, comprising solely of recursivity.
However, if UG consisted only of recursion, UG would not sufficiently explain how the acquisition of language is possible, considering that language input we receive at a young age is random fluctuating in accuracy and is imperfect, and the consistencies of natural language are both extremely complicated and arbitrary (Chater & Christiansen, 2012).
Hence, after considering all these theories, it is evident that there is a need to conduct further research into other areas that might provide other possible explanations.
2. Language as shaped by Cultural Transmission
Chater and Christiansen offer Cultural Transmission as an alternative to explaining the link between UG and language evolution. Cultural Transmission is the process of learning new information through socialization and engagement with those around you. In linguistics, it is the process whereby a language is passed on from one generation to the next in a community. While language could have emerged from genetically-specified UG, it is cultural transmission that catalyzes language evolution. Essentially, it is believed that language, while being formed by cultural transmission, is needed for transmission of other cultural information.
There have also been other studies conducted and articles written that further supports this idea.
Daniel L. Everett studied the language and culture of an indigenous Amazonian tribe in Brazil, the Piraha. He viewed language as a “solution to the communication problem” which aligned with the view above and covered how language and culture were of influence to each other. Everett sees language as “a kind of cognitive enhancing tool but one that is learned and not innate”. This suggested that language was chiseled and sharpened like a tool by cultural transmission.
Recent works by Kenny Smith suggests that linguistic structure develops through cultural evolution, as a result of repetitive cycles of learning and persistent language uses. Smith agrees that “human language allows the open-ended transmission of information”, similar to Chater and Christiansen. Smith believes that social learning is essential, where we use the language of our linguistic community and acquire language through immersion in the rich linguistic environment of the community. This is in line with the definition of cultural transmission.
K Smith from University of Edinburgh states that “Language is a culturally transmitted system – children learn the language of their speech community on the basis of the linguistic behavior of that community.”. Smith further suggests that it is such cultural transmission that results in the possibility of cultural evolution of the linguistic system, which essentially translates to language change over a period of time as a consequence.
With that in mind, it is likely that cultural transmission does shape language. Nevertheless, it is good to note that there is the plausibility that cultural transmission and language are co-dependent on each other and requires the need to look at language evolution with the ‘nature’ with ‘nurture’ point of view. See 3. Cultural Evolution for more information regarding this co-dependency.
2.1 Effects of Cultural Transmission
Language is generally acquired through cultural transmission. Human offsprings naturally pick up languages that they hear most during the critical period of language acquisition. Nonetheless, even in cultural transmission, there have been evidences that suggest that genes also play a role. Studies have shown that the geographical distribution of the variant forms of the two genes active during brain development, ASPM and microcephalin, correlates with the distribution of tonal languages. For example, in places where the ancestral form of the genes is most common, such as in Southeast Asia and sub-Saharan Africa, the languages, such as Chinese and Yoruba, tend to be tonal. Where the derived form predominates, such as in Europe, West Asia, and North Africa, the languages, such as Spanish and German, are non-tonal. It was suggested that different forms of gene direct the cultural evolution of language over multiple generations by causing differences in the brain structures that affect how people hear or speak a language. This meant that cultural transmission of language could shape it in terms of functionality like usage, convenience of communications, with the background help of selective genes. However, further evolution of language is limited by the biological and cognitive constraints of humans.
3. The Neural and Cognitive Basis of Language
Chater and Christiansen (2012) proposes that languages are probabilistic tendencies which are shaped by universal human constraints.
Legend:
Blue Box – All Language possibilities
Orange Arrows – Universal Constraints that limit the Language possibilities
Green Circles – Different languages of the world
3.1 What Helps Shape Our Language
These universal human constraints, which are cognitive and biological in nature, limits the possibilities of linguistic structures that could be learned, processed and transmitted from person to person or generation to generation. Some of these constraints includes; the constraints involving the nature of Thought, constraints from the communicative function of language and constraints from our cognitive mechanism, among a number of other human constraints.
3.1.1 Constraints from Thought
Language allows us to communicate our thoughts. Hence, the nature of thought would surely strongly influence the structure of language. One property of Thought is that Thought is not constrained by a finite inventory of ‘messages’; it consists of a compositional structure in which a limited set of perceptual inputs can create an unlimited set of possible developments. Hence, in order to communicate Thought, language would be shaped in the essence of Thought in having a compositional structure, with a finite set of lexical and grammatical resources to encode an unlimited set of possible messages.
3.1.2 Pragmatic Constraints
The purpose of communication is to convey as much information as efficiently as possible. This influences the development of all languages in trying to create a system that is able to convey as much information as possible with the least effort. Hence, we find universal trends in languages such as the grammaticalization of certain concepts such as ‘aspect’ or ‘tense’ and the occurrences of nominals in most language systems.
3.1.3 Cognitive Constraints
Languages must correspond to human’s sequential learning ability. From early child language acquisition studies such as the Wug Test (Berko, 1958) and familiarization preference procedures (Marcus, Vijayan, Bandi Rao & Vishton, 1999), children have been found to be both rule-learners and statistical learners. The process in which humans learn, process and memorize hence ensure that languages has to be logical and structured such that it can be decoded when transmitted from one person to another. See 4.1: Child Language Acquisition for an in-depth analysis.
3.1.4 Biological Constraints
3.1.4.1 Vocal Apparatus
A human is able to produce sounds between 85 Hz and 155 Hz. This also means that voiced human languages must fall between these frequencies. This constraint was the reason used to differentiate why apes such as Washoe were unable to produce human speech (Harley, 2009) although this particular biological constraint on apes was debunked by Tecumseh Fitch as he proved that monkey’s vocal tracts are human speech-ready (Fitch, de Boer, Mathur & Ghazanfar, 2016).
3.1.4.2 Memory
The limitations to memory too can affect how human language develops. Humans do not have a powerful memory, hence the language we produce would tend to be local rather than long-distance.
3.2 Universal Human Constraints
The greater the number and complexity of constraints that we can identify, the harder it is to unpick them although paradoxically, the greater the number of constraints that we can identify, the simpler it is to understand the universal process of language acquisition. This is because the more constraints there are that are universally shared by all humans, the smaller the number of available options for ‘language’ that a speaker can have.
For studies and real examples of Cultural Adaptation in Language Evolution, see Chapter 3: Language as a Cultural Adaptation
4. Problems of Gene-Language Co-evolution
4.1 What is Gene-Language Co-evolution?
Gene-Language Co-evolution is the idea that biological and language evolution follow the same trajectory, whereby language is a heritable, innate trait like genes. This means that both language and genes are subjected to processes of natural selection. In biology, natural selection is “the process whereby organisms better adapted to their environment tend to survive and have more offspring”. It is regarded as the main process that causes evolution. With that in mind, in the linguistic environment, natural selection would result in adaptations to local environments, resulting in different biological characteristics among different populations of language users.
4.2 Plausibility of the existence of Gene-Language Co-evolution
4.2.1 Reasons for its improbability
As previously mentioned in 4.1, this phenomenon is only possible if language is able to undergo natural selection like genes. Chater and Christiansen suggests that UG could not have co-evolved with natural language itself as they felt that such an occurrence was implausible, evolutionarily speaking. The reasonings are as follows.
Linguistic change is much faster than genetic change. This is due to the ever-changing linguistic environment which causes the supposed “linguistic genes” to be unable to adapt. As such, these supposed genes would have a difficult time undergoing natural selection. Besides, the diffusion of the human population leads to a wide diversity of languages. With gene-language co-evolution only capable of adapting to current linguistic environment, it will not sustain since modern human populations do not seem selectively adapted to learning their own language. This is shown by fact that babies are able to pick up any language as long as they are exposed to it. As such, gene-language co-evolution fails to exist.
4.2.2 Reasons for its probability
Before going into the reasonings, there is the need to define the conditions for natural selection in language. In biology, natural selection occurs when the 4 conditions are present – hereditary, reproduction, variation in fitness or organisms and variation in individual characters. For language, Chater and Christiansen believes that it takes place when the arbitrary and functional aspects of the linguistic environment are present. The arbitrary aspects refer to the absence of any natural or necessary connection between meaning and its sound and form while the functional aspects refer to things like vocabulary size, emphasis on local linguistic processes and so on. Since both aspects are present in the linguistic environment, natural selection could occur and this means that gene-language co-evolution is plausible in this context.
Many studies have been done in favour of this belief that gene and language co-evolves. In one such case, an evolutionary theorist at Harvard University, Erez Lieberman, discovered that English verbs are regularized at a rate inversely proportional to their frequency. This discovery is backed up by evolutionary biologist, Mark Pagel, who deems that this frequency proves that rates of lexical replacement are comparable to the evolutionary rates of genes. This serves as proof of the possibility of language undergoing natural selection like genes and hence, poses the plausibility of gene-language co-evolution.
5. Conclusion
In conclusion, it can be seen that many studies have been conducted in this area, however more studies from cross disciplines may help in establishing a clearer understanding of language and the brain, hence more studies can be done in across these multiple disciplines to better garner a stance regarding our topic.
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