Language Development

Language Development

How are human communication systems distinct from that of other animals?
Animal Communication systems (e.g., Bee Dance)

1.  limited number of forms (displays)

2.  limited number of messages

most forms are innate

Human Communication systems

1.  limited number of basic forms (avg. = 40)

2.  unlimited number of combinations

3.  all languages share the basic forms; combinations differ across languages

4.  infinite number of messages

5.  high transmission rate

6.  all humans learn languages (unless organic problem)

speakers develop Internalized Rule System; native intuition

Language Development

Children must master four basic components of language:

·  Phonology: How words sound and are produced

·  Semantics: The meanings of words and word combinations

·  Syntax: Rules used to put words together into sentences

·  Pragmatics: Conventions and strategies used in effective and socially acceptable verbal interactions

Theoretical Perspectives of Language Development

•  Complex language systems are quickly acquired in childhood

•  Early theorists did not provide an adequate explanation

–  Mostly proposed modeling and reinforcement

•  Newer theoretical perspectives: Nativism, Info. Processing, Sociocultural, Functionalism)

Nativism – inherited mechanism facilitating acquisition of language

•  Sensitive Periods (Genie, Late-learners of ASL, 2nd Lang.)

•  Tends to focus on syntactic development

•  Language Acquisition Device (compared to other theories that believe Lg develops out of more general cognitive abilities); evidence from cases of children with Williams Syndrome

See Fig. 9.1

Information processing perspective…

From an early age infants pay attention to human speech

–  infant can discriminate between /pat/ vs. /bat/

–  Japanese no distinction between /l/ vs. /r/ later vs. rater

Sociocultural Perspective

– Social interaction and culture aid in language development; tends to focus on semantic development

Functionalism: Language development provides practical benefits to children; language is so essential for humans that they will create it (e.g., Nicaraguan Sign Language); the desire to communicate is result of heredity and env’t

Language Development Milestones

·  Cooing (onset 1- 2 mos.)

·  Babbling (onset 4-6 mos.)

·  At 7 mos., Babbling now more language-specific

Sample audiofiles:

http://childes.psy.cmu.edu/topics/clips/clips.html

Infants babble in both signed and spoken language modalities ("Equipotentiality"/"Amodal")

·  Timing of early babbling seems to be due to maturation

·  all infants babble vocally, even if they are deaf

·  all infants "sign babble", even if they have not been exposed to sign

http://www.utsc.utoronto.ca/~petitto/nature.html

Early repertoire of vocal babbling is limited initially; then broader range of sounds (even broader than target language) consisting of the phonemes and syllables that are most common across languages, but by 10 mos. it begins to match pattern of target language.

Summary:

Evidence suggests that babbling is "hardwired" (unfolding with maturation) and "amodal" (i.e., it comes out both vocally and manually in all children regardless of input).

Language Development Milestones

·  preverbal gestures

·  1st Word

(range 8-18 mos, and babbling still continues.)

·  Word + Gesture

·  Gesture recedes, words become dominant

·  Two-word combination

·  Cooing and Babbling language milestones are fairly universal, yet still individual differences in first word, two word milestones

One-word Stage

·  limited by sounds they can control - by 15 months, 10 words, one at a time

·  lasts for six or more months, until vocab. size is about 50

·  deaf children do not spontaneously produce/acquire spoken words

·  a possible 1st word advantage in sign language?

·  Signing babies produce first sign earlier? Controversial research. [textbook is wrong about 18-22 mos on p. 351]

Types of words (Nelson, 1973)
object names (Nouns) like "doggie", "mommy" makes up 66% of early vocab.

·  actions (Verbs) like "give", "bye-bye"

·  Modifiers (Adj) like "mine", "dirty"

·  social words like "yes" or "no", "whassat?”

Function words

Two word stage (18 - 24 months)

·  vocabulary growth...probably about 5 new words a day

·  mostly content words, usually nouns and verbs

Common meanings expressed by children's two word utterances or telegraphic speech

·  often use fixed word order

·  lacking in function words ("closed class items" such as tense endings, articles, prepositions)

·  Children continue to revise and refine rules until age 10, though much is done by age 6 or 7

Acquisition of morphemes depends on structural complexity and semantic complexity; Overregularization errors occur

·  Complex grammatical forms such as negatives, questions, connectives (e.g., and, then), embedded sentences, tag questions

Even later acquired (middle childhood, early adolescence): full passive voice (The glass was broken by Mary), infinitive phrases with same subject as the main verb (John is eager to please vs. John is easy to please)

·  Individual Differences: girls slightly ahead of boys until age 2, then even out;

·  Factors that can influence indiv. diff.: child temperament, SES, cultural emphasis in child-directed speech or linguistic structure of the language