Language Development Major Questions: 1) What is language/what is involved in language? 2) What are the stages of language development? 3) Is language development driven by nurture or nature? What is language? Language has no single definition, but Hockett's list of design features is a popular compromise. By this account, language has the following 9 attributes: 1) Mode of Communication (vocal-auditory, etc) 2) Semanticity (meaningfulness) 3) Pragmatic Function (usefulness) 4) Interchangeability (ability to function as speaker and listener) 5) Cultural Transmission (passed down) 6) Arbitrariness (no necessary relationship between sign and the signified) 7) Discreteness (made up of separable units) 8) Displacement (can refer to something in another place/time) 9) Productivity (can produce a theoretically infinite number of meaningful utterances) Animal Communication (1) All animal communications have the following: mode of communication, semanticity, and pragmatic function. Some have interchangeability, 'cultural' transmission, arbitrariness, and discreteness. Essentially none have displacement and productivity. But there is at least one known animal language that displays displacement – can you guess which? Animal Communication (2) The great and mighty Bee! http://www.youtube.com/watch?v=4NtegAOQpSs For our purposes, know that (human) language: Involves using signs that are not innately related to the things they signify Allows communication of concepts Can be spoken, written, or signed (modes of communication) Can produce a theoretically infinite set of sentences Seems to be unique to humans Language learning involves (1): Phonological development Learn which sounds (phones) influence meaning. These special phones are called phonemes and are the smallest meaningful sound changes in a language. We are able to recognize all phonemes (around 200) and eventually our phonemic inventory narrows to match that of languages we are exposed to (45 sounds for English) Semantic development Learn to manipulate minimal units of meaning, called morphemes. Stems and affixes (prefix, suffix, infix) are two kinds of morphemes. Language learning involves (2): Syntactic development Learn the impact that the ordering of meaningful elements has on meaning. This is called descriptive grammar. This is NOT what we learn in school, but rather how people actually speak. What we are taught in school is called prescriptive grammar. Descriptive grammar only describes the system of use; prescriptive grammar imposes (prescribes) a particular system Pragmatic development Learn the rules of use, including social rules, etc. *Meta-linguistic knowledge This is linguistic knowledge about language: for instance, categorizing words a noun, verb, etc. This may not actually be necessary for language learning but is a common feature. Language learning involves (3): Phonological development Semantic development Syntactic development Pragmatic development *Meta-linguistic knowledge Know these! Methods of word learning Fast mapping (an idea which has come under fire recently, but is still worth discussing) Whole object assumption ('chair' means whole, not part of the thing being referenced) Mutual exclusivity assumption (no thing has more than one name) Pragmatic cues Social context Attention Intentionality Linguistic context Syntactic bootstrapping (using syntactic rules to guess meaning in context) The stages of primary language acquisition: There are five basic stages of language acquisition Cooing: Appears at about 6 months or so. All infants coo using all the phonemes from every language. Even congenitally deaf children coo. Babbling: Appears at around 9 months. Infants are starting to selectively use the phonemes from their native language. One-word utterances: At around 12 months, children start using words. Telegraphic speech: Children start making multi-word utterances that lack function words. (about 2 years old) Normal speech: By about 5-6 years of age, children have almost normal speech Nature or Nurture (1) Skinner: Behaviorism could define the way we learn language. Chomsky: Human language learning appears to be innate in a way that violate behaviorist expectations. Called Nativism. Nature or Nurture (2) What about language could behaviorism not explain? 1) Novel utterances 2) Poverty of stimulus 3) Speed of learning 4) Creolization 5) Language creation Further evidence for Nativism 1) Neurological evidence for dedicated processing 2) Inability of other species to create linguistic utterances even when exposed to language 3) Critical periods for language development 4) Preferential perception for speech sounds (we pay more attention to the differences between speech and non-speech sounds) 5) Costly physiological adaptation (larynx and choking) However... Modern neural network models show some promise for being able to demonstrate how language is learned in a way that does not require special equipment. Nature AND Nurture Both nature and nurture play valuable rolls in language learning. For proper language development you need a human brain and a human environment.