Language Development

Lecture 8 Language Development Psy 313 Progress of Language Development Age Behavior Birth Perceive phonemes; discriminate lang from nonlang; Crying 3 mos Cooing 6 mos Babbling 9 mos First words; holophrases; 18 mos Telegraphic speech; vocabulary spurt 24 mos Beginning of sentences 30 mos Indirect requests; awareness of grammar Prelinguistic Developments    Birth: Prefer lang over nonlang; differentiate basic phonemes chars of world’s langs 1 mo: distinguish sounds of native lang from foreign lang 2 mo: Social smiling; cooing 1 Prelinguistic Developments 3 months: primary intersubjectivity  9 months: secondary intersubjectivity  Theories of Language Acquisition  Behavioral Approach  Nativist Approach  Cognitive Approach  Interactionist Approach Critical Period for Language?   Lenneberg (1967) -- language acquisition must occur before puberty Evidence  Genie -- 13 1/2 year old girl  Sign Language Acquisition in Deaf Children  Learning a Second Language 2 Vocabulary Growth       By 18 mos - 50 words - vocabulary spurt - sudden increase in word acquisition at about 18 mos. By 3 1/2 years 1300 words By 6 years - 10-14,000 words During preschool years, learn avg. 5.5 new words per day By 11 - 40,000 Words     Receptive vocabulary US: Mostly nouns Korea: Mostly verbs 24 months: nouns account for less than half of words Dimensions of language  phonemes -- the basic units of sound  morphemes -- smallest meaningful unit of lang  semantics -- study of word meanings  grammar -- Rules of a lang for the sequencing of words in a sentence & ordering of parts of words 3 Dimensions of lang  Phonemes    Newborn: perceive diff btwn phonemes of langs Shortly afterward, only differentiate sounds part of native lang Morphemes   “Transplanted”  [trans] [plant] [ed] By 8-9 yrs, can use morpheme knowledge to figure out meanings of new words  “treelet” Holophrases  Simple-word utterances of babies that some believe stand for entire phrases or sentences   “Up” “Bottle” Grammar How do children learn to arrange words and parts of words in a way that has meaning to others?    7 months: Sensitive to ordering of words in simple sentences can abstract patterns of word usage from such sentences Later: “My doggy runned away” 4 Semantics    For a young child, word meanings are dominated by contexts of action As the child acquires formal conceptual categories of lang, structure of word meanings changes accordingly Assessed by “What kind of thing is a _____?” Problems of referential ambiguity  Overextensions:  Underextensions: Sentences    Utterances of 2+ words: Language milestone at end of infancy (age 2 years) Can vary order of words to create different meanings Increasing complexity…   Measured in number of morphemes (units of meaning): MLU (mean length of utterance) “Boys aren’t playing” = 3 words, but 6 morphemes (boy, s, are, not, play, ing) 5 Language Dev in Preschool Years    Language skills become more sophisticated Begin period with reasonably good linguistic (language) capabilities  but gaps in language production (speech) and comprehension (understanding) By the end of the preschool years  they can hold their own with adults  language skills develop By age 3…     children use plurals and possessive forms of nouns (boys/boy's) employ the past tense (adding -ed) use articles (the/a) can ask and answer complex questions  Private speech  Social speech increases Illustrates the acquisition of some of the rules of Language and supports Chomsky's claims of an inborn ability to find grammatical structure. wugs 6 Role of the Environment  Deaf children (whose parents won’t sign or who “home sign”) and hearing children raised by deaf parents  Develop basic rudiments of grammar (2- or 3-word phrases), but not more complex ones Can language children hear at home significantly influences their language dev?  Hart and Risley (1995) - the effects of poverty on lang. Differential Language Exposure Parents at different economic levels provide different language experiences. Professional parents and working parents direct more words toward their children than welfare parents? Why could this be so? 7