Language, Cognitive, Social and Physical Development

Development:Why study?

• Child is father to the man• Analysis of complex system• Heredity --environment issues• Heritability = Vg/Vt (variance)• Why difficult? --right experiment• Role of culture & socialization:

Rosseau/Victor of Aveyron

Development: Basic Models• Basic issue: heritability (nature-nurture

interactions)• --no development: small adults!• --progressive differentiation• --instinct (maturation alone --> devel.)• --readiness (maturation is a pre-req for

learning)• --critical period (maturation is a pre-req but

opportunity disappears)• --stages and waves

Physical and Brain Development

• At birth, the human brain weighs approximately 350 grams.

• By the first year. the brain weighs approximately 1000 grams.

• The adult brain weighs 1200-1400 grams.

Fig. 5-2, p. 123

In the beginning….—to approximately two weeks

Fig. 5-3, p. 123

Physical and Brain Development: Synaptic Growth & Pruning

Physical Development

• In Utero:– Zygote: conception-2 weeks– Embryo: 2 weeks-2 months (8 weeks)

• Cell differentiation– Fetus: 2 months to birth

• Functioning organ systems develop, early reflexes seen (e.g. non-nutritive sucking)

• Infancy: – Very slow development, comparatively– Brain development takes off– Spurts of growth throughout childhood

(body and brain)

Physical and Brain Development

• From birth:– Reflexes:

• Grasping• Rooting• Foot flexing

– Sensory• Discriminate high and low sounds, vowels,

mother’s voice• Very near-sighted, but can discriminate

brightness and color and track moving objects

Physical Development: (Progressive Differentiation)

• Gross motor skills– 7-8 months: sitting up– 8-10 months: crawling– 10-12 months: “cruising”– 12-15 months: walking– 2 years: hopping on one foot, kicking– 4 years: jumping rope, balancing on one foot

• Fine motor skills– 1 month: reflexive grasp– 4 months: reaching, hands at midline– 6 months: reach precisely, grabs at objects– 12-14 months: throwing objects– 2 years: unscrewing jars– 3 years: cutting with scissors, holding pencil– 6 years: writing, drawing shapes

Physical/Attentional Development

• Brain:– Making/pruning connections

• Attention– Infants have little selective attention. If

something is interesting, they will look at it.– Development of Prefrontal cortex

(PFC)development of attentional control• 1-2 years: single-channeled attention: can concentrate

on task, but not external verbal/visual stimuli• 2-3 years: still single-channeled, but with help can

adjust focus back and forth• 3-4 years: single-channeled, but can adjust focus on

their own• 4-5: two-channeled, but short attention span• 5-6: audio, visual, and manipulatory channels

integrated

Child Language Development

• How do children get from being completely non-verbal to being expert speakers? (Habituation and diary studies)1. Can distinguish between vowel sounds (/a/ vs. /o/)- in

utero2. Can distinguish between all contrasts- from birth3. Infant – mother “conversations shortly after birth!4. Categorical perception of speech sounds (8-12 months)5. Babbling: 6 months (front to back, then words back to

front)6. One word stage: ~1 year7. Two word stage: ~2 years (vocab is about 50 words)8. Then syntax & multiword utterances; gradually increase

in complexity9. …..But, as always, great variability

Language• Once underway, children develop language

fast and effortlessly

1 year: 1 word

2 years: 300 words

3 years: 1000 words

4 years: 5000 words

5 years: 10000 words

18 years: 60000 words

0

50

100

150

200

10 12 14 16 18 20 22

Age in Months

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The Innateness of Language• Behaviorism: Language is learned like

everything else: Stimulus-response theory– We say something, we receive feedback,

which encourages us to say it again

• BUT: We can say things we’ve never heard; we can produce new structures.

• Chomsky: Language is innate to humans– Language Acquisition Device (LAD)– Universal Grammar– Poverty of the Stimulus

Innateness of Language?

• Chomsky’s Solution Universal Grammar: all natural languages share a common

structure that arises from the way our brain is designed to construct and process language.

• We have evolved specialized mechanisms for language because communication is advantageous

Problem - “Universal” structure could come from the constraints of the environment and communicative needs

Arguments for Innateness• Semi-dedicated brain tissue (Broca's,

Wernicke's)• Critical period• Early start and early development +

difficulty of task (complexity of rules, 5000+ words by age 5 + semi-complete set of rules

• Overgeneralization: not mimicry • Syntactic uniqueness (numerous issues)

(many instances: wild chn. animals, no-input lang. etc.)

• Poor teaching and poor examples (parsing problem)

Arguments for Innateness

• Dedicated brain regions – Broca’s and Wernicke’s areas– Damage to Broca’s area, near the motor cortex, is associated with difficulties

in producing speech

– Damage to Wernicke’s area, which is near the auditory cortex, is linked to difficulties with meaning

• FOXP2 gene

– Family missing the gene

show severe speech and

language impairments

The Critical Period

• If language learning doesn’t occur before a certain time, language will be impaired (pre-puberty)

• Victor (+ Genie & others) examples of experience impaired language acquisition

• Congenitally Deaf children of hearing parents not exposed to ASL have great trouble acquiring language

• Nicaraguan Sign Language!

Critical Period?• Performance on a test of

English grammar by adults originally from Korea and China was directly related to the age at which they came to the United States and were exposed to English

• The scores of adults who emigrated before the age of 7 are indistinguishable from those of native English speakers

The Nature of Feedback (Poverty of the Stimulus)

1. Children get little or no direct instruction.2. Children get little feedback and don’t listen to what they

get -- so why do they ever correct their errors?3. Children hear many ungrammatical structures not

identified as such -- how do they come to learn these are wrong?

4. In some cultures adults don’t speak to children.5. Children will make up a language if they are not given one

-- deaf children of hearing parents.6. Some cost (simple vs. elaborated language) to low input.

Verb Learning• Two types of past

tense verbs:– Regular: talked, liked,

hated– Irregular: ate, went,

was

• U-shaped curve of language learning– Early: correct usage– Middle:

overgeneralization– Late: correct usage

The Language Gene

• SLI: Specific Language Impairment: Language is impaired without signs of impairment in other areas (motor, cognitive, etc.)

• The FOXP2 gene– Members of the KE family with a corruption of

this gene had SLI; the others didn’t.– The Language Gene?

The Language Gene

Cognitive Development

…and the Work of Jean Piaget

Important Concepts Within Piaget’s Model

• Schemes: Mental model of the world that we use to represent, organize, and interpret our experiences.

• Assimilation: Integrating new experiences into an existing scheme.

• Accommodation: Changing or modifying a scheme in order to incorporate a new experience.

Four Major Stages of Cognitive Development

1. Sensorimotor (0-2 years)2. Preoperational (2-7 years)3. Concrete Operations (7-11 years)4. Formal Operations (12+ years)

Sensorimotor Period

• From birth to ~2 yrs old• Actions progress from simple

reflexes to deliberate movements

• Object permanence – realize object still exists even when it can’t be perceived

• Internal representation – ability to think about objects/events not immediately present

Preoperational Period• From ~2 yrs to ~7 yrs• Learn to use symbols, signs and language• Egocentrism – cannot understand another person’s point of

view (but nursery school pics/code switching)• Failure of conservation – do not yet understand that

quantity remains the same despite appearance

Concrete Operational Period

• From ~7 yrs to ~11 yrs• Thinking becomes systematic, quantitative and

logical• Success at all conservation tasks – number, solid

quantity, liquid quantity: fun experiments!• Decentration of perception – ability to classify

objects in terms of more than one dimension

Formal Operational Period• From ~11 yrs to adult• Apply logical and systematic

thought to abstract problems• Deductive reasoning – specific

conclusions based on general hypotheses

• Inductive reasoning – make generalizations based on specific observations

• Handling multiple variables simultaneously

Strengths of Piaget’s theory• Good “feel” for what

children’s thinking is like • Asks the right questions• Covers broad age span• Covers broad spectrum of

developments in children’s thinking

• Surprising observations• Interplay of content &

mechanism

Weaknesses of Piaget’s theory

• Underestimates competence – children succeed earlier than predicted

• Can’t explain dissociations – success or failure depends on the way concept is tested

• Sometimes, no discrete stages - development occurs somewhat gradually or incrementally

Technique: Habituation

• Infants like to look at objects that are new and interesting to them

• Procedure– Familiarization: Object presented repeatedly until infants

no longer look at it much– New object introduced

• Method: Infants look longer at new object—allows testing of whether they perceive object as new or old

Kids sometimes smarter than you think: Occluded rod experiment

• 4-month-old infants familiarized with A, then presented with either B or C

• Results – Looked longer at C than B

• Conclusions– Broken rod more novel than

unbroken rod– Rod in display A was

originally perceived as unbroken

Kids sometimes smarter than you think: Drawbridge experiment

• 4.5 month old infants• Two conditions

– B is ‘possible’– C is ‘impossible’

• Results – Looked longer at C

• Conclusions– Infants know box exists,

even when hidden – 4.5 month olds understand

object permanence

Kids not always smarter than you think: A-not-B experiment

• Experimenter hides toy under cover A• 9-month-old infant successfully retrieves toy• After several successful retrievals, experimenter then hides toy under

cover B• Results - Child still searches under cover A, even though he/she

watched the toy being hidden• Conclusions – 9 month olds do not understand object permanence

Information-Processing Theories

• Thinking = information processing– Representation of information– Processes - applied to representations– Constraints - memory limits constrain representation

and processing• Cognitive development = change in information

processing capability– Precise analysis of change mechanisms

• Change produced through continuous self-modification– Outcomes of child’s actions change information

processing in the future

Memory representations & capacity

• Leg-string Infants remembered that kicking made mobile move after 2 months

•Working memory span increases with age

Rehearsal as information processing

• Increase in rehearsal speed leads to increase in working memory capacity

• Older children do better on recall tests because they use rehearsal as a memory strategy

Social Development

• This topic gets at the core of who and what we are.

• First: Basic Theories of Development– Behavioral: patterns of reward/punishment

-Cognitive: Growth in understanding (+ Piaget on moral development)

-Social learning theory (modeling & imitation are central)-- Bobo

-Psychoanalytic theory & Attachment: lmportance of childhood (child as the father of the man)

Attachment & Importance of Childhood (Psychoanalytic View)

• Harlow Work incl. therapist monkeys, but there is need for therapy!

• Hospitalism: Spitz et at./orphanage --> retarded adult

• Ainsworth work: a solid base from which to explore the world….sometimes!

Attachment Styles• Secure - Uses caregiver as a secure base for exploration. Upset by

departure of parent but easily calmed when they return and can continue to play.

• Resistant – Does not use parent as a secure base, often stays close to them. Upset when they leave but not comforted by their return.

• Avoidant – Little affect while playing. No visible stress upon parents departure, ignores them on return. Treats the stranger similarly to the caregiver.

• Disorganized – no clear attachment patter. Show freezing or repetitive behavior.

Attachment

• http://www.youtube.com/watch?v=_O60TYAIgC4 Work of Harlow

• https://www.youtube.com/watch?v=hmdycJQi4QA Wild Children (Genie + Victor)

Strange Situation Results

Middle class kids:• 60% secure• 15% anxious/resistant• 10% anxious avoidant• 15% disorganized• But is it causal? unclear. (Could be due to

child's temperament?)

Moral Development: KohlbergA woman was near death from a special kind of cancer. There

was one drug that the doctors thought might save her. It was a form of radium that a druggist in the same town had recently discovered. The drug was expensive to make, but the druggist was charging ten times what the drug cost him to produce. He paid $200 for the radium and charged $2,000 for a small dose of the drug. The sick woman's husband, Heinz, went to everyone he knew to borrow the money, but he could only get together about $1,000 which is half of what it cost. He told the druggist that his wife was dying and asked him to sell it cheaper or let him pay later. But the druggist said: “No, I discovered the drug and I'm going to make money from it.” So Heinz got desperate and broke into the man's store to steal the drug for his wife. Should Heinz have broken into the laboratory to steal the drug for his wife? Why or why not

Moral Thought-->Moral Action?Arrestees During the Free Speech Movement

level 1 2 3 4 5 6 % arrested M 0 60 18 6 41 75

" F 0 33* 9 12 57 86*

____* = small n

Need for Achievement (McClelland)

• A. the measure: Murray TAT• B. the finding: varying amounts of nAch• C. predicts performance (goals people set,

rate of advancement of mngr)• D. childrearing aspects: expectations for

independence• E. societal implications/findings: electrical

power and other things• F. 30 countries and KWH corr.= .53 (corr.

with 1925, not 1950)• G. class differences

Child Rearing Styles

• Autocratic (authoritarian), authoritative,permissive, uninvolved

• Affects anger, withdrawnness, independence• Class differences: external vs.. internal control

( cog. diss. theory --minimum external control)-- forbidden toy exper. Lepper Green & Nisbett

Child Rearing Strategies

• Long term vs. short term• Most important task you will face….and

there’s no instruction manual!

Major Influences on Soc. Dev.

• Maturational• Attachment• Parenting Style• Social learning• Identification• Lesson of Wild Child