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Theories and Measurement of Intelligence

Introduction

  • Presenter: Dr. Lizzie Dent
  • Focus on intelligence, its definitions, the measurement approaches, and influential figures in psychology related to intelligence testing.

Task 1: Intelligence Tests

  • Objective: Review and discuss the different types of intelligence tests available on Canvas.
  • Questions to consider:
    • What do these tests measure?
    • Can these tests be considered valid assessments of intelligence?
    • How to explain these measures of intelligence to a lay person?

Historical Overview of Intelligence Theories

Sir Francis Galton (1822-1911)
  • Interests in human variation, particularly intelligence.
  • Asserted that "superior qualities" are heritable.
  • Recognized as the "forefather of intelligence testing."
  • Proposed that intelligence could be gauged through sensory measures:
    • Reaction times
    • Pain recognition
    • Color distinction
    • Eye movements
    • Hearing ability
  • Intelligent individuals exhibit quick responses to stimuli; those with slower responses were considered less capable.
  • Issues with Galton's Methods:
    • Reliance on physiological measures could be restrictive and may not encapsulate the entirety of intelligence.
Alfred Binet (1857-1911)
  • Developed a psychological test, as opposed to a physiological one.
  • With Theodore Simon, created the Binet-Simon Scale (1905).
    • Included circa 30 everyday tasks of progressive difficulty:
    • Shaking hands
    • Naming body parts
    • Reproducing drawings or sentences
    • Repeating 7 random digits
    • Finding rhymes for difficult words
    • Providing word definitions
  • Binet's test proved useful in differentiating typical and atypical mental development by establishing mental age independent of chronological age.
Lewis Terman (1877-1956)
  • Identified that Binet-Simon test was unsuited for Californian children.
  • Enhanced the Binet-Simon test by adding 40 items and adjusting existing ones for better suitability for children aged 4-14.
    • Example benchmarks:
    • At age 4, recognition of longer lines.
    • At age 9, understanding of dates and days.
  • Tested on 1000 children, emphasizing importance of representative sampling for generalization purposes.
The Intelligence Quotient (IQ)
  • Developed by William Stern (1912).
  • Observed that mental age varies proportionally with chronological age: mental age of 8 vs. chronological age of 10.
  • Formula:
    IQ=(mental agechronological age)×100IQ = \left( \frac{mental\ age}{chronological\ age} \right) \times 100
  • Average IQ: 100 (where mental age equals chronological age).
  • Terman incorporated IQ in his version of the Stanford-Binet test, stressing the necessity of representative samples for accurate norm development.
Robert Y