Intelligence and Cognitive Abilities

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Intelligence and Cognitive Abilities
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Intelligence

• What is intelligence? Or, what is (is not )
  intelligent behavior?
• How do you know if someone is intelligent?
• If you wanted to find out if someone was
  intelligent what would you do?

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Intelligence

• Why are these questions important?

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Some ideas for intelligent behavior

• Ability to
• Think abstractly
• To plan
• To gather information
• To understand complex ideas and to manipulate
  them for later use
• To solve problems
• To reason, e.g., deduction and induction
• To adapt effectively to the environment and
  overcome obstacles
• To learn from experience
• To adapt to a novel situation

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Intelligence

• Intelligence should be universal
• Some behaviors everyone should agree are
  intelligent
• Exactly how intelligence is expressed will differ
  given the context
• Language skills are good indicators of
  intelligence but would be invalid measure if the
  person did not speak the language

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Intelligence

• Cooper definition of mental ability
• Persons performance on some task that has
  substantial information-processing component when
  the person is trying to perform that task as well
  as possible
• Traits that relate to cognitive ability and
  information processing

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Three As

• Ability
• Present competence to perform a task
• Achievement
• Present competence that reflects specific
  learning experience or instruction
• Aptitude
• Potential to acquire particular skills, with
  reference toward future performance

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Three As

• Ability
• Skill you have, e.g., reading or mechanical
  ability
• Achievement
• Given instruction what do you now know? E.g.,
  exam in Psy3135
• Aptitude
• How well might you performance given appropriate
  instruction motivation? E.g., SAT and college
  performance

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Under and Overachievers

• Underachiever
• Achievement tests or performance falls below what
  would be predicted by aptitude or intellectual
  ability tests
• Learning disability (LD) defined as 2 SD
  difference between achievement and aptitude
• Overachiever
• Achievement tests or performance exceeds the
  level predicted by aptitude or intellectual
  ability tests

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Three As

• 3 As are distinct but there is substantial
  overlap
• In practical terms, its very difficult to
  completely separate them at least in terms of
  measurement

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Three As

• Function of educational system is to foster
  cognitive development
• Therefore, achievement and aptitude tend to be
  tied
• Also, persons with high aptitude tend to receive
  the most instruction

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What Intelligence is not

• Its important to distinguish what intelligence
  is not
• Not just the opposite of intelligent behavior
• What does not belong in the content domain of
  intelligence?
• Why is this important?

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Not Intelligence

• Intelligence does not include every skill or
  ability a person could have
• Jimmi Hendrix was a musical genius
• Michael Jordan was an athletic genius
• That doesnt make them an intellectual genius

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Gardners Theory of Multiple Intelligences

• 7 different and independent intelligences
• Linguistic
• Logical-mathematical
• Musical
• Spatial
• Bodily-kinesthetic
• Interpersonal
• Intrapersonal

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Not Intelligence

• How can we figure out what is and is not
  intelligence?
• Remember validity?

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Intelligence

• However you want to define or measure it
• Intelligence is the single most consequential
  individual difference trait
• Some researchers even think of life as a series
  of poorly defined intelligence tests, i.e.,
  situations that require cognitive reasoning

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Brief History

• Sir Francis Galton
• Father of individual differences
• Believed intelligence was an inherited
  characteristic
• Inheritance of eminence
• Eminent individuals tended to run in families
• Conducted family studies of eminence

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Galton study of eminence

• Eminence occurred aprox. 250 per million
  individuals (.025)
• The 1000 eminent men he identified came from only
  300 families
• Therefore, eminence runs in families
• Any problems with these conclusions?

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Galton and eminence

• Reputation only a proxy for intelligence
• Confound with social status
• Suggested adoption study to avoid the confound
• Studied adopted sons of popes

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Anthropometric Laboratory

• Galton (later Cattell) devised several
  sensorimotor tests to measure intelligence
• Make fine discriminations in pitch, sight, or
  texture
• Physical traits such as head size, arm length,
  grip strength
• How do you think that turned out?

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Galton other discoveries

• Assortative mating
• clever men marry silly women
• NO, eminent men marry eminent women
• Positive manifold
• men of genius are uhealthy puny being-all brain
  and no muscle-weak sighted and generally poor
  constitutions
• NO, intellect is associated with health,
  strength, vitality, and long, productive life

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Range of Human Capacity

• As many people below the mean as above it
• Talent deviated from an average
• Intelligence had a symmetric, normal distribution

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2 types of Mental Retardation

• Familial MR
• Individuals at the low end of the intelligence
  distribution
• MR due to natural causes mild MR runs in
  families
• Organic MR
• MR due to some unusual event
• Congenital factors (e.g., Downs syndrome) or
  serious brain injury
• Severe impairment doesnt run in families

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Alfred Binet

• Devised first successful and widely used
  intelligence test (1904)
• Wanted to identify children in public schools
  that will special needs that would require
  intervention
• Why use a test and not teachers recommendation?

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Binet and Intelligence tests

• Intelligence tests are more objective
• Predict success and allow for ready
  classification
• Diagnose MR
• Doctors were consulted, but no standard
• Develop age norms
• Establish cut-offs scores

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Binet Intelligence tests

• Measure higher mental processes
• Memory
• General knowledge
• Abstract Reasoning
• Attention
• Comprehension
• Coordination
• Visual judgment

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Intelligence Quotient (IQ)

• Evaluate intelligence with respect to age
• IQ (mental age / chronological age)100

IQ (MA/CA) 100
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IQ

• Thus, if a 9-year old can answer questions of the
  same difficulty level as most 12-year-olds then
• IQ (12/9) 100 133
• Also, add up many different scales to calculate a
  total score
• General reasoning ability

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Binet and IQ

• How did it work out? Good.
• Discriminated MR from normal children
• Discriminated MR from behavior problems
• IQ scores predicted grades
• Eventually transplanted to the U.S. by Terman and
  evolved into the Stanford-Binet

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Spearmans Two-factor Theory (1904)

• All individual tests of intelligence consist of
  two additive components of variance
• General variance (g)
• Specific variance (s)
• Also error variance, (e)

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Two-factor Theory

• g is the variance shared by all tests of
  intelligence
• General intelligence
• If two tests are heavily loaded with g, expect
  them to correlate highly

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Factor Analysis

• Data reduction technique
• Identifies latent or unobserved variables that
  account for the correlations among the observed
  variables
• Each observed variable is a function of the
  latent variable(s)

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Factor Analysis Continued

• FA attempts to understand the structure of a
  correlation/covariance matrix by simplifying the
  information
• An alternative way of organizing the information

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Factor Loadings

• Regression coefficient (correlation) between the
  factor and the observed variable
• How much variance the factor accounts for in the
  observed variable (standardized to 1.0)
• Higher factor loadings indicate the observed
  variable is a better marker (measure) of the
  factor

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r voc-memory .50
r arith-memory .39
r voc-arith .55
G-factor
.60
.80
.70
Vocabulary
Arithmetic
Memory
.60
.70
.80
V specific
M specific
A specific
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r voc-memory .50
r arith-memory .39
r voc-arith .55
G-factor
.60
.80
.70
Vocabulary
Arithmetic
Memory
.40
.55
.45
.45
.55
.58
V specific
A specific
M specific
Error
Error
Error
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Multiple Factor Theories

• G is not the whole story
• Group factors are at a level between specific
  (primary) measures and g
• These factors are common to a group of tests

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Rotated Factor Matrix
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Group Factor Examples

• From Thurstones Primary Mental Abilities
• Verbal comprehension (vocabulary)
• Word fluency (letter naming)
• Number (capacity for arithmetic)
• Space (visualizations)
• Associative memory (paired associates)
• Perceptual speed (visual processing speed)
• Reasoning (number series)

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gf-gc Theory

• Fluid intelligence (gf)
• Abilities to think, reason, and acquire new
  knowledge
• Crystalized intelligence (gc)
• Knowledge and understanding that a person has
  acquired

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Hierarchical Theories

• Integrate the single (g) and multiple group
  factor approaches

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Hierarchical Structure

• G is at the top
• Second level is Major Group Factors
• Third level is Minor Group Factors
• Bottom level is specific factors (Spearmans s)

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Hierarchical Structure
G-factor
Km
Ved
Verbal
Number
Spatial
Visualization
S5
S6
S7
S8
S1
S2
S3
S4
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Wechsler Adult Intelligence Scales

• David Wechsler devised adult intelligence test
  (1939)
• Now most widely used measure of intelligence for
  adults and children
• IQ is calculated differently
• IQ declines as people age

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Deviation IQ

• Compare scores to a normative sample of a similar
  age
• Mean 100, SD 15

Deviation IQ (z-score ?) x
(z-score 15) 100
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Deviation IQ

• Average range 85 to 115
• Gifted range 130
• Mentally retarded lt 70
• How does that correspond to SD units?

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WAIS-IV Subtests

• 11 subtests, with 3 supplementary scales
• Full scale IQ
• Verbal IQ
• Performance IQ
• Index Scores
• Verbal Comprehension
• Perceptual Organizational
• Working Memory
• Processing Speed

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Verbal Subtests

• Vocabulary (VC)
• Define words
• Best measure of G
• Similarities (VC)
• Tell how two things are alike
• Abstract verbal reasoning
• Information (VC)
• Questions of general knowledge
• Crystalized intelligence

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Verbal Subtests

• Arithmetic (WM)
• Solve arithmetic problems in your head
• Working memory, mathematical reasoning
• Digit Span (WM)
• Repeat a list of numbers forwards and backwards
• Working memory

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Performance Subtests

• Block Design (PO)
• Make designs using colored cubes
• Spatial and nonverbal reasoning
• Matrix Reasoning (PO)
• Given an incomplete pattern, choose from a number
  of options how to be complete a picture
• Pattern recognition, non-verbal reasoning

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Performance Subtests

• Digit Symbol Coding (PS)
• Paired associates
• Each number has a mark put the mark that goes
  with the number
• Processing speed, learning ability or speed of
  acquisition

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WAIS-IV Subtests

• Each subtest assesses slightly different mental
  abilities
• All a measure of G
• Multiple measures that assess multiple abilities
  provides a comprehensive measure of a persons
  intelligence
• Highly reliable
• Test-retest correlation .90