E-411 PRMA

Lecture 15 - Intelligence

Christopher David Desjardins

Intelligence

What is intelligence?

What makes someone intelligent?

Write one item that you measures intelligence

Intelligence is ...

  • There is no consensus on what intelligence is

  • There is no single instrument to measure intelligence

  • To Sternberg's public, intelligence means

    • "Reasons logically and well"

    • "Reads widely"

    • "Displays common sense"

    • "Keeps an open mind"

    • "Reads with high comprehension"

Intelligence could involve (Sternberg's findings)

  • Problem-solving ability

  • Verbal ability

  • Social competence

  • + academic behaviors (Academic intelligence)

  • + interest learning & culture (Everyday intelligence)

Interactionist views of intelligence

Galton - heritable; possessing great sensory (hearing, visual) abilities; measured sensorimotor and perception task

Binet - involves reasoning, judgment, memory, and abstraction and these cannot be assessed seperately

Wechsler - aggregate capacity made of measurable, qualitatively different abilities that interact in a complex, non-additive ways; affected by nonintellective factors (e.g. personality traits); verbal and performance abilities (historical?)

Piaget - evolving biological adaption to the world; assimilation and accomodation

Factor analysis and intelligence

  • Structure of intelligence exmamined thoroughly using factor analysis to explore relationships between abilities measured on tests

  • Spearman (1927), two-factor theory of intelligence

  • Existence of a general ability factor, g and specific factors, s, and unexplained factor variability (e)

No group factors

Group factors

  • Group factors common to a group of activities but not g

  • Thurstone purposed a 7 factor structure of intelligence but could not escape g

  • Gardner adds interpersonal (working with others) and intrapersonal (working with yourself) to intelligence

    • Motivation for the CHC model

    • Cattell proposed a theory consisting of crystallized and fluid intelligence (no g)

    • crystallized intelligence, Gc, ability to use skills, experience, & knowledge (e.g. retrieving and applying information)

    • fluid intelligence, Gf, capacity for solving novel problems

    • Horn added several factors Gs (e.g. visual, auditory processing); some are vulnerable, others maintained

    • Carroll hierarchical view of intelligence

    Carroll's model

    CHC model

    McGrew and colleagues tried to reconcile these approaches

    Proposed a modified Carroll model without a g

    Omission of g based on the lack of utility for their needs

    McGrew calls for adoption of the CHC model and made data available here

    CHC model

    There are 10 broad-stratum abilities

    • fluid, crystallized, quantitative knowledge, reading/writing ability, short-term memory, visual processing, auditory processing, long-term storage/retrieval, processing speed (perform automatic cognitive tasks, couple minutes), and decision time/speed (reaction time, couple seconds)

    There are 70 narrow-stratum abilities

    Why are there so many models?

    What is the problem with factor analysis?

    What is the problem with exploratory vs. confirmatory factor analysis?

    Information-processing framework

    • Rather than using factor analysis to derive "what" intelligence is, examine how information is processed

    • simultaneous processing, integration at once

    • successive processing, sequential integration

    • Extant tests do not take into account problem solving strategy

    • Sternberg proposed successful intelligence, how well we adapt, share, shape, select environments that confirm to personal and societal success

    How to measure intelligence?

    • Myriad of tasks developed depending on age of testtaker
    • Infants focused on sensorimotor skills; shift towards verbal and performance abilities as children age
    • Mental age has fallen out of favor
    • For children, tests often used for school placement
    • Adults, test more diverse and typically used clinically

    Problems in intelligence

    • Nature vs. nurture

      • Preformationism & predeterminism - slave to your genes
      • Twin studies
      • Interactionist view - unlimited potential

    • Stability

      • Young adult intelligence most important predictor of intelligence of older adults
      • Aging, physical/mental health, medications - confounders
      • "Early ripe, early rot"

    More problems

    Flynn effect - rise in intelligence test scores expected to occur on a normed intelligence test from the date the test was first normed.

    TED Talk by Flynn

    Personality \(\equiv\) Intelligence

    Gender differences?

    Family effects starting in the womb?

    Cultural considerations? Culture-loading and creation of culture-fair tests

    What can we find out about the standard IQ tests?

    Vist either Stanford-Binet or Weschler website.

    • Purpose
    • Usuage
    • How it was normed
    • Validity information

    Stanford-Binet IQ test

    • Conceived by Binet to screen for children with developmental disabilities
    • Originally intelligence calculated as the ratio of mental age to true age
    • Deviation score, mean of 100 and standard deviation of 15
    • Measures fluid reasoning (fluid), knowledge (crystallized), quantitative knowledge, visual-spatial, and working memory (see Table 10 - 2)
    • Adaptive

    Fifth edition

    • Full scale IQ from ten subtests

    • Subtest scores can be combined to get other composite scores (e.g. verbal score)

    • Standardized for the USA population aged 2 to 85

    • Manual reports high internal consistency, test-restest, and inter-rater reliability (though items with low reliability were pruned)

    • Criterion-Related VE from concurrent and predictive data

    • Use in a clinical population and factor structure unclear

    Weschler intelligence tests

    • Age-appropriate tests for very young children; children; adults

    • All originally used a verbal, performance, and FSIQ, now only young children uses V and P scales

    • Many subtests and items specific just to Weschler's tests (Table 10 - 3)

    • Consists of core subtest and supplementals used to extract clinical information

    • Short forms exist, but discouraged

    • Good psychometric properties?

    Measurement check

    Will the reliablity and validity statistics reported in a technical manual be applicable to you as a test administrator?

    If they report coefficient alpha of 0.95, what will your coefficient alpha be?

    If the correlation between the IQ score obtained from the Stanford-Binet and an achievement test is reported as .75, will you have that same correlation for your group?

    Comparison and other tests

    • Both purport to measure intelligence

    • Highly correlated, differ by amount of g

    • Both work within the CHC model

    • Both represent gold standard

    • Different factor structures and definitions of intelligence

    • Kaufman test focus on processing not structure

    Group tests

    • USA army developed tests for recruits in WWI

    • Alpha, those who could read, Beta, those who couldn't

    • Assigned duty and service based on performance

    • Tests used in post-war because they were much cheaper

    • Later, Army General Classification Test and Armed Service Vocational Aptitute Battery

    • Also used in the schools in the USA for placement (not as much now)