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Language Language DevelopmentDevelopment

Gaia ScerifRoom 426, Ext. 67926

gs@psychology.nottingham.ac.ukOffice Hours: Thurs 12-2

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Lecture List - Lecture List - 5th November (Dr. Scerif): Revision and introduction to

theories of development 11th November (Prof. O’Malley): Language acquisition:

Nativist approaches 12th November (Prof. O’Malley): Language acquisition:

Socio-interactionist accounts 18th November: Video – Theories of language acquisition 19th November (Dr. Pitchford): Influences on language

acquisition: The effects of sensory deprivation 25th November: (Dr. Pitchford): Stage theories of language

development: Literacy 1 26th November (Dr. Pitchford): Stage theories of language

development: Literacy 2 2nd December (Dr. Pitchford): Conceptual development: The

case of colour cognition 1 3rd December (Dr. Pitchford): Conceptual development: The

case of colour cognition 2 9th December (Dr. Scerif): Review of theoretical issues

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Learning objectivesLearning objectives

* Theories of language acquisition

1. Developmental course of language acquisition? By what age / in what sequence do particular language abilities develop?

2. Driving force behind language development? Mechanisms responsible for developmental changes in children’s language abilities?

3. In what sense are our language abilities innate? To what extent is linguistic knowledge wired directly into the brain? To what extent does it develop as a function of the interaction between innate learning mechanisms and the structure of the environment?

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Developmental Course Developmental Course of Language of Language AcquisitionAcquisition

Pre-speech Sounds (0 to 16 weeks)

Vocal Play (16 weeks to 6 months)

Babbling (6 to 10 months)

Single Word Utterances (10 to 18 months)

Two-word Utterances (18 months)

Telegraphic Speech (2 years)

Full Sentences (2 years 6 months)

Vegetative sounds, Cooing, Laughter

First speech-like sounds - Vowels (a e i o u) before Consonants (c, g, t)

Strings of consonant vowel syllables (e.g. Bababa, Gugugu)

Child uses small repertoire of single words (e.g. Mummy, doggie, more, gone)

Onset of multi-word speech - correlated with sharp increase in vocabulary size

Multi-word speech with many grammatical elements missing (e.g. Adam kick ball, Dolly not like it, What doing?)

Multi-word speech with more and more of the grammatical elements included (e.g. I’m kicking the ball, Dolly doesn’t like it; What are you doing?)

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What drives language What drives language development?development?

The Role of ImitationImitation obviously has a role to play in language

development. However:1. From early in development children produce

utterances that they could never have heard: Word class errors: More read, Other one

spoon, That’s a pretty Case-marking errors: Me can do it, Him like

it, Her has a tummy ache Morphological overgeneralisations: Two

sheeps; She holded the rabbits; They went to the graveyard and unburied her

Argument structure errors: Don’t say me that, This jumper sweats me, Stay your eye on that car in front; I’m pouring him with water

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What drives language What drives language development?development?

The Role of ImitationImitation obviously has a role to play in language

development. However:2. Children unable to imitate utterances they

cannot spontaneously produceDe Villiers & De Villiers (1979)Child: KurkaAdult: Turtle. Say “Tur”Child: TurAdult: Say “Tle”Child: TleAdult: Say “Turtle”Child: Kurka

Braine (1971)Child: Want other one spoonAdult: You want the other spoon?Child: Yes. I want other one spoonAdult: Can you say “the other spoon”?Child: Other … one … spoonAdult: Say “Other”Child: OtherAdult: “Spoon”Child: SpoonAdult: “Other … spoon”Child: Other … spoon. Now give me theother one spoon

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Learning Theory (Skinner, 1957)

Language development as a process of learning by shaping and reinforcement. Child’s language learning as analogous to the learning of a rat in a Skinner box:

1. Rat happens to depress a lever in the presence of a particular stimulus (e.g. a light or tone)

2. Lever press is reinforced (e.g. by the provision of a food pellet)

3. Rat is said to be conditioned by reinforcement to depress lever in the presence of the tone

4. By selectively reinforcing only certain types or sequences of lever presses, rat’s behaviour can be shaped into more and more complex sequences of responses

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Language learning as conditioning

1. Child babbles or imitates sound pattern made by adult in presence of particular stimulus (e.g. produces ‘Wa(nt)’ when hungry)

2. Adults reinforce child’s verbal behaviour (e.g. respond to ‘Wa(nt)’ by providing food)

3. Child conditioned through positive reinforcement to emit sound pattern more often in presence of that stimulus (e.g. produces ‘Wa(nt)’ more often when hungry because this behaviour results in provision of food)

4. Child’s speech sounds shaped by selective reinforcement until producing adult-like words (e.g. ‘Wa(nt)’ becomes progressively more like ‘Want’ as adult becomes progressively more demanding about the sound patterns she will respond to)

5. If it is assumed that each word can act as a stimulus for the next, sentences can be built up as sequences of learned responses (e.g. Child learns to say ‘Want milk’ by producing ‘Want’ as conditioned response to its own hunger and ‘Milk’ as conditioned response to the word ‘Want’)

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Empirical Problems

1. Parents do not provide consistent enough feedback for children to learn language this way.

Brown & Hanlon (1970) showed that parents tend to respond to children’s utterances on the basis of their truth value rather than their grammatical correctness

Child: That’s a doggie (pointing at a horse)Adult: No, that’s a horsie (stressed)Child: We goed in the parkAdult: That’s right. And we fed the ducks, didn’t

we?

Parents reinforce ungrammatical utterances if true and reject grammatical utterances if false

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Empirical Problems2. Children are often resistant to correction even

when it does occur

Child: Nobody don't like meAdult: No, say “nobody likes me”Child: Nobody don't like me.Adult: No, say “nobody likes me”Child: Nobody don't like me.Adult: No, say “nobody likes me”Child: Nobody don't like me (8 times)Adult: No. Now listen carefully. Say “nobody likes

me”Child: Oh! Nobody don't likes me

Negative feedback not the major driving force in grammatical development

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U-shaped pattern of development

After a period of correct production, children’s performance declines as they begin to make over-generalisation errors, before improving again

PhonologyTurtle *Kurka Turtle

MorphologyWent *Goed Went

Argument StructureSay that to me *Say me that Say that to me

From an early age, children seem to be learning rules and exceptions to rules

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Chomsky’s CritiqueLearning theories cannot explain the

development of language because they start out with a false description of what language is like:

1. Language cannot be analysed into simple associations between stimuli and responsesWhat stimulus controls the verbal responses ‘Blair’ or

‘Afghanistan’? How easy is it to tell what a person will say in response to the clock striking twelve?

2. Language has underlying structure that cannot be explained in terms of learned sequences of responsesSentences are not strings of words but hierarchical

structures into which words can be inserted as a function of their place within a system of rules

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SummarySummary

1. Early theories of language development attempted to account for language learning in terms of general processes such as imitation and conditioning through reinforcement

2. Such theories not consistent either with what we know about children’s language-learning environments or with the developmental sequence in which their linguistic abilities unfold

3. Critique of learning theory approaches: Chomsky argued that they could not explain the development of language because they started out with false view of what language was like

4. Chomsky: the nature of language is such that it could only be acquired if the child already had a great deal of innate domain-specific knowledge about the way language works

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Nativism: Nativism: Language Language

Genes?Genes?

• Can genetic variability specify and determine language development?

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• Can genetic variability specify and determine language development?

Nativism: Nativism: Language Language

Genes?Genes?