Cognitive Processes
PSY 334
Chapter 13 – Individual
Differences in Cognition
August 28, 2003
Cognitive Development
 Humans are born with immature brains.
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Brain doubles in size during first year.
Brain size doubles again by puberty.
Much neural development takes place after
birth.
 Slow physical growth may provide a
longer dependence on adults, giving
time for the acquisition of knowledge.
Piaget’s Stages
 Provides a structure for organizing
observations of child behavior.
 Currently being revised, corrected and
restructured.
 Controversy over idea that development
progresses in stages rather than as a
continuous process.
Studies of Conservation
 Knowledge of what properties of the
world are preserved under various
transformations.
 Object permanence – sensorimotor
stage
 Conservation of quantity, volume, weight
changes at 6, the boundary between
preoperational and concrete-operational.
What Develops
 Two explanations for changes in
children’s thinking:
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They think better – more working memory.
They know better – more facts.
 Probably both occur, due to neural
changes:
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Increase in synaptic connections.
Myelination increases neural transmission
speed.
Memory Space Theory
 Case – growing working memory
capacity is key to developmental
changes.
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Some problems require more facts to be
kept in memory.
Increased neural speed leads to increased
memory capacity.
Practice reduces demands on working
memory.
Examples
 Noelting’s juice problems:
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< 4 – all orange juice must be in one
pitcher
4-5 – pick pitcher with most orange juice
7-8 – compare OJ with water
9-10 – compute difference between OJ &
water
 Kail’s mental rotation problems – mental
speed may increase due to practice.
Importance of Knowledge
 Chi suggests developmental differences
may be knowledge-related.
 Kids do worse on memory tasks
because they know less about the world.
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Chess expert children do better at chess
memory, worse on digit span.
Adults more familiar with digits, so do
better.
 Soccer memory study – only expertise
mattered, not grade level.
Cognition and Aging
 Decreases in IQ performance scores
occur after age 20:
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Related to speed of response on tests.
 Older adults do better on jobs.
 Age-related declines in brain function:
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Cell loss, shrinkage & atrophy.
Compensatory growth of remaining cells.
Brain-related degenerative disorders such
as Alzheimer’s.
Productivity in Old Age
 With age, loss of neural function is
steadily offset by growth of knowledge.
 While the 30s may be the time of peak
performance, very high performance
frequently continues into 40s & 50s.
 Speed of neural processing changes so
less information can be held in working
memory.
Psychometrics
 Measures of performance of individuals
on a number of tasks – examination of
correlations across such tasks.
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IQ Tests – Binet, Stanford-Binet, Wechsler
Mental age vs deviation IQ.
 Factor analysis of performance scores:
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Attempt to explain intercorrelations among
subtests.
Ongoing debate about identifying factors.
Factor Theories
 Spearman – one general factor called “g”
 Multiple factors:
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Thurstone – 3 (verbal, spatial, reasoning)
Guilford – 120
 Cattell’s theory:
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Crystallized intelligence (acquired
knowledge) – increases with age
Fluid intelligence – decreases with age.
Horn added spatial intelligence to fluid.
Carroll’s Three Strata
 Lowest stratum – specific abilities (e.g.,
be a physicist), not inheritable.
 Second stratum – broader abilities
(verbal & spatial ability, reasoning,
crystallized vs fluid).
 Third stratum – correlations among
second stratum abilities to form “g”
Kinds of Abilities
 Reasoning ability:
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Sternberg connects psychometrics to the
information-processing approach.
People who score high on IQ tests also
perform reasoning steps more quickly.
 Verbal ability:
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People who recall words more rapidly do
better on verbal ability tests.
Working memory capacity is related to
verbal ability.
Kinds of Abilities (Cont.)
 Spatial ability:
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Rate of mental rotation is slower for those
with lower spatial ability test scores.
People with high spatial ability may choose
to solve a problem spatially, not verbally.
 Differences in abilities may result from
differences in rates of processing and
working-memory capacities.
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Unclear whether this is innate or a
difference in practice (nature vs nurture).
Gardner’s Multiple
Intelligences
 Gardner proposed that seven different
intelligences are supported by different
kinds of knowledge representation:
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Separate neural mechanisms.
Separate developmental histories.
Cross-cultural universals in the display of
such abilities.
 Abilities: linguistic, musical,
mathematical, spatial, bodily kinesthetic,
personal (self-understanding, social).
Critique of Multiple
Intelligences
 Strong evidence for distinct linguistic and
spatial intelligence.
 Mathematical intelligence closely related
to spatial so may not be distinct.
 Remaining intelligences not usually
considered cognitive but may be
universal.
 Gardner argues that intelligence is not
unitary and thus hard to compare.