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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
Nu
mb
er
of
Wo
rds
Sa
id
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