What does the language experiment with Nim Chimpsky prove about Chomsky’s claim that language is exclusively a human attribute?
In 1986 Noam Chomsky presented a theory about language acquisition and capabilities for this within the human race. He claimed that children do not learn language and are instead born with ‘Universal Grammar’, which in turn causes them to have an ability to pick up any language (dubbed ‘language instinct’ by Steven Pinker, 1994). In order for this to be proven correct, one of the key determining features of language acquisition is discontinuous jumps in the child/primate’s progress. This essay will evaluate these three factors off which Chomsky’s theory is based and compare the generic human example to the experiment done on the chimpanzee Neam ‘Nim’ Chimpsky (Herbert Terrace, Thomas Bever, Laura-Ann Petitto, 1973-2000) who was raised in a human family environment from just after birth and treated as a human child (Pinker, 1994). This will be in attempt to prove that Chomsky’s claim, while may not necessarily wholly correct, does have some scientific grounding and may be proven correct in the future when further research is performed.
The ‘Universal Grammar’ that Chomsky claims humans have is a rudimentary grammar knowledge which is built into our DNA from birth. He defines it as ‘the system of categories, mechanisms and constraints shared by all human languages and considered to be innate’ (Chomsky, 1986). This system predicts that there will be nouns and has an inbuilt strategy for modifying them. The brain is constantly on the lookout for this article system from the minute the child enters the world. However, this rests solely on the premise that all languages around the globe share certain structural properties, otherwise the grammar would have to differentiate based upon the location in which you are born. It has since been proven there are many similarities within languages, experts citing approximately four hundred functional categories (Heine and Kuteva, 2002) although views on this vary widely. Chomsky also suggests that the process by which sentences are perceived as correct or incorrect is universal and independent of meaning regardless of the language they are spoken in (Dubuc, 2010). This theory is based on the existence of formal universals (i.e. the rules which enable sentences, phrases and syllables to be understood) and substantive universals (i.e. grammatical categories and functions) (Tomasello, 2013) and their importance to creating and sustaining conversations. From the study of Nim it cannot be said that he understood grammar or even had the capability to, thus proving (at least in the case of this chimpanzee) that Chomsky’s theory has some qualitative basis. Throughout the course of the study, Nim created over twenty thousand potentially grammatical sentences (e.g. more + object and verb + noun not vice versa); however the phrase banana + me was performed three times more than me + banana. Some of the researchers thought that this could be an example of a foundation for grammatical knowledge, however as the American Sign Language (ASL) Nim was taught did not differentiate between the signs for ‘me’ and ‘my’ it is impossible to tell whether he understood grammar (insomuch as he was attempting to say ‘give the banana to me’ or whether he meant ‘my banana’, in which case he was in error the majority of the time) (Wynne, 2007). In addition, whilst Nim learnt approximately one hundred and twenty-five signs and could string them together into sentences, the longer ones often had no grammar, as in the example of his longest sentence ‘give orange me give eat orange me eat orange give me eat orange give me you’. This shows that there is no real innate understanding of grammar as the normal phrase order is verb + noun and whilst this is true for the first three words, from then it immediately stops making sense ‘give eat’ (verb + verb), clearly incorrect grammar. In addition, the phrases signed often included ‘hug’, ‘me’ and ‘Nim’ which fit with almost every other sign he knew and he was often rewarded for using. This then shows more of an operant conditioning style of learning than an inbuilt knowledge of grammar (Tomasello, 2013). Nim could effectively string any two words together and be rewarded for this which would cause him to remember it as a stimulus for reward the next time. As a result of this, Chomsky’s claim may appear to have some scientific basis for further research.
The concept of ‘language instinct’, whist named thusly by Pinker, is actually a large proportion of Chomsky’s theory. It states that in the presence of Universal Grammar, it is easy to pick up any language in the world, due to the structural similarities between them combined with the inbuilt grammar knowledge it is thought all humans are born with. In order for this to be truly called an ‘instinct’ however, there must be little explicit instruction in how to craft sentences; in other words there must be some natural knowledge and input from the child rather than learning simply through observation and direct imitation. Darwin called language ‘an instinct tendency to acquire an art’ (Pinker, 1994) which suggests that this idea predates both Chomsky and Pinker and as such, must have some scientific grounding. When we look at the study of Nim Chimpsky, Chomsky’s theory becomes even more substantiated. He was rarely found to be the one to initiate conversations, instead only signing in response to a question or phrase from one of his teachers (90% of his signing was through this call-and-response method) and often simply imitated the signs they were making. It was recorded that at least 50% of Nim’s signing was just copying the signs made to him (Premack, 1971). It was noted that he also often grabbed objects before signing for them, which could be taken simply to be a lack of manners as it is so often portrayed within younger children; but it is more likely to show that Nim did not ever rely upon ASL as a primary form of communication and simply reverted to using it when there was a necessity or he was likely to be rewarded for doing so. This again links back into the idea not of Nim understanding or having an innate knowledge of language and grammar, but simply his use of language being the result of a long trial of operant conditioning. This is backed up by Terrace’s statement, “much of the apes’ behaviour is pure drill” (Wynne, 2007) which seems to show that there is no real language instinct acting here.
The final marker to show that language is an exclusively human attribute is that of the discontinuous jumps in the process of learning or gaining language. Chomsky’s theory suggests that due to the combination of Universal Grammar and a ‘language instinct’, when a phrase such as the + noun is heard, it should mean that the specific grammatical rule for that noun class (i.e. common nouns, proper nouns, pronouns, etc.) is immediately grasped and from that point onwards, can be freely applied to that entire class (Evans, 2014). This then leads to the discontinuous jumps in language knowledge, as every time a new rule is learnt there should be a large spike and advance in language usage. Chomsky describes language as a mutation which produces a phenotype well outside the range of variation previously existing in the population (Evans, 2014), and as such these easily discernible jumps in language acquisition becomes known as a macromutation. However, when we consider Nim’s case this does not seem to appear. Nim’s signs were often highly repetitive (Petitto and Seidenberg, 1979) and his sentences did not appear to increase in length as his vocabulary advanced, the average sentence length being approximately 1.25 signs (Hart, 2015). He also appeared to learn signs at a fairly steady rate, purportedly learning 125 signs in just two years (Adler, 2008), however Petitto estimated that Nim’s vocabulary was closer to 25 signs. This cannot be called language as this is a doubly articulated system (i.e. object + state combined syntactically to create a meaning) and as shown earlier in this essay it is questionable what the meanings of Nim’s sentences were (Wade, 1980). This proves another part of Chomsky’s theory to be correct as Nim’s language learning process did not contain any discontinuous jumps in his understanding and grasp of language.
In conclusion, it is safe to say that Chomsky’s claim is fairly valid. Whilst the study of Nim and his acquisition of language whilst being raised like a human clearly proves the theory correct, this cannot be said of all species or even of all higher primates. In this case though, it can be said that Nim did not have Universal Grammar due to the longer sentences being no more than a jumble of signs however this cannot be conclusively proven due to the lack of differentiation between the signs for ‘me’ and ‘my’. Neither did Nim have any sign of a ‘language instinct’ as he seemed to sign sentences and phrases that he had learnt gained rewards, showing this set of experiments to be flawed as they had become more of an operant conditioning experiment and as such made the results invalid. Finally there were no discontinuous leaps in Nim’s sentence structure and length as he increased his vocabulary, thus proving that the elements laid out by Chomsky as markers of language knowledge were simply absent from the beginning, showing them to be innate to humans, or at the very least, absent from chimpanzees.
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