Language Development

Human language is

• A communication system
• A symbolic system (ie, the words represent something)
• A rule governed system (syntax and grammar)
• Productive

There is a common fallacy that ‘children learn by imitation’ [behaviourist?] but if this were the case people would only be able to say things which they had heard which is clearly not true, each of us is capable of generating grammatical sentences which are entirely novel.

The following language systems are involved when learning to speak

• Pragmatic system
• Phonological system
• Syntactic system
• Word meaning

Aspects of a pragmatic system

1. Turn taking
2. Initiating interactions
3. Maintaining conversations
4. Repairing faulty conversations

Phonological system
Infants learn to divide speech stream into meaningful units, this is helped by “motherese”. Some researchers [who?] argue that a caregiver’s speech helps the child learn because of the use of :

• simple grammatical forms
• exaggerated intonation (rising tones at the ends of sentences and increased marking of word boundaries)
• pauses between phrases that help the child to recognise familiar words in a speech stream

A phoneme is a set of sounds that are not physically identical but which speakers of a language treat as equivalent sounds (see also the Wikipedia entry for phoneme). Infants can discriminate between phonemes which, according to nativists, suggests that categorical speech may be an innate mechanism.

[The study by Werker & Desjardins has been omitted for now but I will leave this quote in; “Six-month olds can distinguish or produce every sound in virtually every human language. But within a mere four months, nearly two thirds of this capacity has been sliced away.”]

Speech production

The ability to talk lags behind the ability to perceive sounds. All children pass through the same phases of speech production and the apparent universality of early sounds and babbling suggests that maturation plays an important role in speech production (nativist). However children must hear adult sounds to produce the correct pronounciation (empiricist). The capacity to produce sounds reflects a combination of hereditary and environmental factors.

Stages

• Reflexive vocalisations (birth - 2 months): cries, coughs, burps, sneezes
• Cooing and laughing (2 -4 months)
• Babbling and vocal play (4 - 6 months)
• Canonical babbling (6 - 10 months): eg, ‘mamamama’
• Modulated babbling (10 months on): acquisition of intonation patterns

Syntactic system

Stages

• The one-word period (10 - 18 months): Single word utterances
• The two-word period (18 - 24 months): Two word utterances, most likely words that are relevant to their environment
• Multi-word utterances (2.5 - 5 years): Great increase in vocabularly and grammar, there is a tendency for over generalizations (eg, ‘ballareening’) and over regularization (eg, ‘thinked’)

The logical problem of language acquistion.
How do children do it?
How do they learn the correct grammar?
Chomsky argues that all children are born with an innate, genetic, knowledge of language. This is the Language Acquisition Device (LAD) which contains knowledge of Universal Grammar (UG). The UG is a set of principles which are common to all human language and a set of parameters which vary according to the language being learnt. Because the child is given a basic innate foundation the task of learning becomes simpler. Only languages which confirm to the UG principles could be learnt.

Critique
The role of parents in providing language models is important (since children learn what their parents have said).
Newport, Gleitman and Gleitman (1975) [1977?] found that mothers produced ungrammatical sentences less than one-tenth of 1 percent of the time [what is the significance of this?].
Children may be born with a predisposition to learn a language rather than an innate ability.

Summary of theories of language development

• Nativists: Infants are born with innate capacities and knowledge specific to language (eg, Chomsky)
• Empiricists: Children acquire language because of their experiences with language (eg, through ‘motherese’)
• Middle road: Aspects of language developed and influenced by innate predispositions however environment still plays an important role

References
Werker, Janet F. and Renee N. Desjardins (1995). “Listening to Speech in the First Year of Life: Experiential Influences on Phoneme Perception.” Current Directions in Psychological Science. June 1995: 76-81.