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
Can Infants Discriminate among speech sounds?
Newborn YES, can detect most common contrasts across all languages
(Japanese infant can detect /l/ vs. /r/
6-8 mos. Losing ability to discriminate non-essential contrasts. By age 1,
they can only distinguish for their own language sounds (e.g.,
Japanese cannot detect /l/ vs. /r/; English speaking baby has only
one /s/)
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
All Dry
Bye-bye car
Our car
No bed
More hot
Airplane allgone
See baby
I shut
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