1 The evolution of languageIntroduction to Linguistics III The evolution of language
2 Historical views of language acquisitionIntroduction to Linguistics Historical views of language acquisition B.F. Skinner Behaviorist theory infants learn language from other human role models through a process involving imitation, rewards, and practice N. Chomsky Nativist theory Children are born equipped with an innate template for language, and this blueprint aids the child in the task of constructing a grammar for their language J. Piaget Constructivist theory Language is acquired within the context of the child's broader intellectual development. Language is not an independent system, but part of our general cognitive makeup
3 Poverty of stimulus problemIntroduction to Linguistics Poverty of stimulus problem The poverty of the stimulus argument is the claim that primary linguistic data (i.e. the linguistic utterances heard by a child) do not contain enough information to uniquely specify the grammar used to produce them. Premises: - Language is not explicitly taught - The degenerate nature of data Positive evidence the set of grammatical sentences that the language learner has access to, as a result of observing the speech of others הנה ילדים שאהבו את הסרט Negative evidence the evidence available to the language learner about what is not grammatical *הנה ילדים האהבו את הסרט - The rarity of negative evidence
4 Poverty of stimulus problemIntroduction to Linguistics Poverty of stimulus problem Language acquisition is like learning chess: - Only by watching - No explanation of the rules (knowledge about language is never taught) - Some portion of the moves are illegal )children often hear ungrammatical fragments of speech) - But we don’t know which! (Negative evidence is rare) Conclusion: children must have some form of innate Language Acquisition Device (LAD) that provides additional knowledge to language learners
5 Language acquisition deviceIntroduction to Linguistics Language acquisition device More evidence for an innate human capacity to acquire language comes from the following observations: The stages of language development occur at about the same ages in most children Children’s language development follows a similar pattern across cultures. Deaf children who have not been exposed to a language may make up their own language (Nicaraguan Sign Language case)
6 The Hardest problem in science?Introduction to Linguistics The Hardest problem in science? In 1859, Darwin’s published his monumental work, “on the origin of species”, which is considered to be the foundation of evolutionary biology How can we track down the evolution of language? It is nearly impossible to bring direct evidence of the form of primitive language… There are no language fossils In 1866, the Linguistic society of Paris chose to put a ban on discussion of the of the evolution of language – treating it as so speculative as to be worthless… “The attitude of most linguists to evolutionary theories of the origin of language tends to be one of agnosticism. Psychologists, biologists, ethologists and others might say, if they so wish, that language must have evolved from some non-linguistic signaling-system; the fact remains, linguists might reply, that there is no actual evidence from language to support this belief” (Lyons, 1977)
7 to Major transitions Linguistics IntroductionEight major transitions in the evolution of life: Maynard Smith & Szathmáry’s (1997) These events in the history of our planet have brought radical changes in the way evolution works Why is the emergence of language such a significant event? These transitions have some features in common… One way of thinking about language is as a coding system that maps between two spaces: the space of concepts and intentions on the one hand, and of articulation and perception on the other
8 to Language r/evolution Linguistics IntroductionWorldwide Spread of Homo Sapiens Neanderthal australopithecine Homo erectus Extinct!
9 to Language r/evolution Linguistics IntroductionWhat was so revolutionary in the Homo Sapiens’ language? The Lion-by-the-river theory The social brain hypothesis Fictive language theory
10 to Language r/evolution Linguistics IntroductionWhat was so revolutionary in the Homo Sapiens’ language? Unbounded (DNA-free) transmission of cultural information Biological explanations History story-telling The Emergence of language
11 The emergence of languageIntroduction to Linguistics The emergence of language “Language is a product of our large brain size” Definitely not!! Large brain does not predict language capacity Evidence from high-functioning human microcephalics microcephaly Normal head size Autistics have significant problems in both the acquisition and expression of language, and yet early in development often have larger brains than healthy children Children with one hemisphere removed prior to the full acquisition of language often display normal language expression and comprehension
12 Social evolution of languageIntroduction to Linguistics Social evolution of language British anthropologist Robin Dunbar’s “gossip” theory is based on social complexity Dunbar pointed out that the majority of people’s conversations are devoted to gathering news either about the people they are speaking to or about third parties: in other words, to gossiping. Among primates, neocortex size varies in proportion to social group size. Apparently, the larger the group a primate lives in, the more brain it needs to keep track of social relationships within the group. Social pressure leads to selective pressure: Dunbar suggests that larger brains evolved in primates in order to permit larger social groups Dunbar Number: If we look at human brain size from the perspective of this hypothesis, we predict a "natural" group size for humans of about 150.
13 Social evolution of languageIntroduction to Linguistics Social evolution of language In primate societies, it is grooming (picking nits out of fur) that plays a major factor in establishing and maintaining social bonds. The bigger the primate group, the more time on average each member spends in grooming others. If we look at human social relations in this perspective, then with a group size of 150, we should have to spend 40% of the day in grooming. This is far too high to be practical -- the highest actual proportion observed among primates is 20% (Gelada baboons). Dunbar suggests that our ancestors, facing hard times on the African plains, very badly needed to live in larger groups. "Gossiping" (in whatever form it first arose) made it possible to form and maintain social bonds more efficiently than grooming, both because more than two can do it at once, and also because you can actually do some useful work (like gathering or processing food) at the same time.
14 The emergence of languageIntroduction to Linguistics The emergence of language Broca’s and Wernicke’s homologues have been identified in non-human primate brains Lesioning the monkey homologue of Broca’s area does not impair vocalization Rilling, 2014 Monkey calls instead depend upon the limbic system and brainstem (more ancient systems) comprehension of species-specific vocalizations seems to depend on similar neural substrates in humans and macaque monkeys Like Broca’s area, human Wernicke’s area has functional properties not found in its non-human homologue, such as phonological processing
15 Is a gradual evolution of human language plausible?Introduction to Linguistics The emergence of language II “Language is a product of macro-mutation” Probably not. It is hard to imagine that a single mutation could have resulted in such a complex behavior A gradual story for the evolution of the eye is possible: it turns out that there are “intermediate” eyes that are indeed useful and there is a plausible evolutionary trajectory from these intermediate forms to the modern eye. Is a gradual evolution of human language plausible?
16 Evolutionary questionsIntroduction to Linguistics Evolutionary questions Language origin – the first step from something that is not language to something that is language Language evolution – the gradual development of speech-to-meaning mapping “We’ll start by speaking in simple declarative sentences.” There is a huge gulf between the communication systems of our nearest primate relatives and human language. If language is a one-off phenomenon - an autapomorphy - then how can we apply the standard methodologies from evolutionary biology?
17 Dividing the language facultyIntroduction to Linguistics Dividing the language faculty the problems in discussions of language in its evolutionary context may arise from treating the language faculty as a unitary whole Minimal account of human uniqueness As an alternative, Hauser, Chomsky & Fitch propose two different senses of the term biological language faculty: - FLB (the faculty of language in the broad sense) - FLN (the faculty of language In the narrow sense) More specifically, they put forward the strong hypothesis that FLN is essentially limited to a mechanism implementing recursion Having made this distinction, they set out three logically possible hypotheses about the evolution of the faculty of language: 1. FLB is homologous to animal communication. All aspects of FLB (including FLN) can be found relatively unchanged in animals 2. FLB is a derived, uniquely human adaptation to language. 3. Only FLN is uniquely human. Hauser, Chomsky & Fitch, science 2002
18 Debating the language facultyIntroduction to Linguistics Debating the language faculty Pinker & Jackendoff (2005) do not accept this minimal description, and argue that there is much more that is special to language and to humans than merely the capacity for recursion. Firstly, they suggest that there are non-syntactic aspects of language that are uniquely human. For example, for them the huge size and rapid acquisition of the lexicon strongly suggests that this is a uniquely human adaptation. A second criticism that Pinker & Jackendoff (2005) have is that treating FLN as containing simply a mechanism for recursive computation oversimplifies the syntactic aspects of human language.
19 to The descended larynx Linguistics IntroductionOther mammals / Human infants Humans (Adult)
20 to Language gene? Linguistics IntroductionKE family: In 1990, scientists became interested in a certain family in London, half of whose family members have speech disorders. By analyzing the KE family DNA sequences, scientists found that the speech problem was caused by a mutation in the FOXP2 gene located on chromosome 7 region 7q31