INTELLIGENCE

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INTELLIGENCE

• Chapter 8

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What is Intelligence?

• Typical Definitions
• mental abilities needed to select, adapt to, and
  shape environments
• 2. abilities to
• profit from experience
• solve problems
• reason effectively
• meet challenges and achieve goals
• Formal definition proves elusive.

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Is intelligence a single reasoning ability?

• Charles Spearmans g-factor (general
  intelligence)
• Speed of mental processing
• Separate reasoning skills Robert Sternberg
• Analytical, practical, creative (Triarchic)
• Multiple abilities Howard Gardner
• Linguistic, mathematical, musical, kinesthetic,
  intrapersonal, interpersonal, spatial, naturalist

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Origins of IQ Score

• (MA/CA) x 100
• MA Mental Age
• a measure of intelligence test performance
  devised by Binet where a given level of test
  performance is represented by the average age of
  children who perform at that level.
• (For example, a child who does as well as the
  average 8-year-old is said to have a mental age
  of 8.)
• CA Chronological Age, or the age of the test
  taker

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Intelligence Tests

• Most popular Wechsler 1939
• WAIS-IV adults
• Wechsler Adult Intelligence Scale
• WISC-IV children
• Weschler Intelligence Scale for Children
• WPPSI-III - preschoolers
• Wechsler Preschool Primary Scale of
  Intelligence
• Stanford - Binet

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Assessing Intelligence

• Standardization
• Today meaningful IQ scores are defined by
  comparison with the performance of a pretested
  standardization group
• Normal Curve
• the symmetrical bell-shaped curve that describes
  the distribution of many physical and
  psychological attributes including IQ
• most scores fall near the average fewer and
  fewer scores lie near the extremes

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The Normal Curve
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Is intelligence inherited?

• Partially This is a nature-nurture question.
• Are differences in ethnic group averages
  hereditary?
• No. this is best explained culturally.

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Plant-Pot Analogy
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Early Interventions

• High-quality center-based interventions improve
  intelligence school achievement
• Effects strongest for poor children with
  uneducated parents
• Positive effects linger into adolescence, but get
  smaller
• Effects best sustained where programs continue
  into middle school

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Tests of Infant Intelligence

• Less verbal, more perceptual-motor
• Do not correlate well with later measures of IQ
• Often called DQ (Developmental Quotient)

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Tests of Infant Intelligence

• Gesell (1934) detect abnormal infants for
  adoption agencies
• Motor, language, adapative, personal-social
• Bayley Scales of Infant Development (1969)
• Mental, motor behavior measures
• Diagnose developmental delays 1 to 42 mos.

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Fagan Test of Infant Intelligence (1992)

• Encoding attributes
• Detecting similarities differences among
  objects
• Forming mental representations
• Retrieving mental representations

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Fagan Test of Infant Intelligence (1992)

• Works well across cultures
• Predicts intelligence in childhood adolescence
• Quicker habituation more looking in
  dishabituation reflects more effective
  information processing.

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Stability of Intelligence

• Using groups of different ages (6, 8, 10, 18),
  get high correlations (.70 - .90) across ages
  2-18
• One study testing the same children between the
  ages of 2 ½ 17 found changes of up to 40 points
  in one-third of them (average range 28 points)

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Intelligence in Adulthood

• Horne (1980s)
• Cross sectional
• Groups differed in educational opportunities
• Problem of cohort effects
• Found fluid intelligence to decline crystallized
  intelligence not to

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Changes in Mental Abilities in Adulthood

• Crystallized intelligence skills that use
  accumulated knowledge experience, good judgment
  mastery of social conventions.
• IQ test vocabulary, general information,
  logical reasoning, verbal analogy
• These skills maintain or increase.

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Changes in Mental Abilities in Adulthood

• Fluid intelligence detecting relationships
  among stimuli, speed of processing, working
  memory abstract reasoning
• IQ test number series, spatial visualization,
  picture sequencing
• These skills decline from middle adulthood.

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The Seattle Longitudinal Study

• Midlife is a period of peak performance on 5
  abilities..
• Vocabulary
• Verbal memory
• Number
• Spatial orientation
• Inductive reasoning
• Perceptual speed drops from the 20s
• K. Werner Schaie

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Changes in IQ Test Performance in Adulthood

• Cognitive mechanics neurological hardware of
  the brain affected by biology health prone to
  decline with age
• Cognitive pragmatics skills, comprehension
  cultural experience may improve with age
• Paul Baltes (1990s 2000s)

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Changes in IQ Test Performance

• Many studies show that crystallized intelligence
  increases, fluid processing speed declines.
• General Conclusion Declines are due to a
  general slowing of the Central Nervous System.
• There are large individual differences.

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Use It or Lose It

• Factors correlating with less decline, better
  performance on cognitive tests
• above-average education
• highly complex occupations
• stimulating leisure pursuits
• better social situation
• absence of disease