General Psychology
Intelligence

History

• With the introduction of Evolutionary Theory, the idea that intelligence was the key to human survival and that individuals varied in this quality was very popular at the turn of the century.

• Binet developed the first accepted measure of intelligence which identified behaviors related to school success.

• Lewis Terman adapted Binet's test for Americans and called it the Stanford-Binet (1916). Tested verbal skills and introduced the notion of IQ (intelligence quotient) defined as mental age/chronological age.

• Wechsler IQ test became most popular because it successfully measure verbal and non verbal skills.

Wechsler

• WPPSI, WISC, and WAIS

• Measures verbal, performance, and freedom from distractibility

• Deviation IQ: normal distribution

• Psychometric properties:

  • Standardization- sampling, administration, and scoring

  • Reliability- consistency, test-retest

  • Validity- measure what it claims to measure, predictive 

• Uses:

  • Mental retardation: low IQ, poor adaptive behavior

  • Learning disorders: normal IQ (although gap between verbal/performance) and poor achievement

  • ADHD: poor freedom from distractibility

Correlations and causes of IQ

• Correlates: family size, SES, ethnicity

• Causes

  • Genetic- heritability of .4-.7 and reaction range of 25 points

  • Environmental- influential in lowering IQ (nutrition, stimulation)

Redefining intelligence

• Lumpers vs splitters (general versus specific)

• Sternberg (moderate splitter)

  • componential (verbal and convergent)

  • experiential (creative and divergent)

  • contextual (practical and street smart)