Intelligence Theories and Definitions

Study Notes

No agreed-upon definition of intelligence
Boring's definition: intelligence is what intelligence tests measure
Key questions:
- Is intelligence one ability or multiple?
- Is intelligence exclusive to humans?

Francis Galton (1890s):
- Believed intelligence stemmed from sensory abilities
- Tested 9,000 individuals, no strong link found between sensory abilities and intelligence
- Helen Keller (blind and deaf) is a counterexample - highly accomplished

Developed first intelligence test
Defined intelligence as higher mental processes and abstract thinking
Intelligence test development marked beginning of IQ testing
By 1921, experts identified key intelligence abilities:
- Abstract reasoning
- Adapting to new environments
- Acquiring knowledge
- Learning from experiences

Charles Spearman (1927):
- Proposed general intelligence (g): overall cognitive ability
- Specific intelligence (s): abilities specific to certain tasks
Thurstone (1938):
- Argued against "g"
- Proposed primary mental abilities:
  - Verbal comprehension
  - Word fluency
  - Numeric ability
  - Spatial visualization
  - Associative memory
  - Perceptual speed
  - Inductive reasoning

Cattell & Horn (1940s/1960s):
- Fluid intelligence: ability to solve novel problems, think abstractly
- Crystallized intelligence: accumulated knowledge, facts, and experiences
- Fluid intelligence transitions into crystallized intelligence over time

Gardner (1983, 1999):
- Many ways to be intelligent, various intelligences are distinct and independent
- Examples: linguistic, spatial, musical, kinesthetic
- An "intelligence" is:
  - Distinct ability, independent from others
  - Likely an evolutionary advantage
  - Some people may be exceptional in only this specific area
Critiques:
- Are these truly "intelligences" or just talents?
- Independent nature of abilities is questionable
- Some categories lack clear falsifiability (proof)

Three types of intelligence:
- Analytical intelligence ("book smarts"): logical reasoning, problem-solving
- Practical intelligence ("street smarts"): handling everyday tasks
- Creative intelligence: thinking of novel solutions
Critique: Components may not be as independent as claimed, potentially linked to 'g'

Intelligence linked to different brain regions:
- Frontal lobe: executive function, planning, impulse control
- Prefrontal cortex: thinking, planning, language; active during 'g' tasks
- Temporal lobe: auditory processing, memory
- Parietal lobe: spatial abilities
- Occipital lobe: visual-spatial processing
Processing speed:
- Reaction time: faster reaction time often linked to intelligence
- Working memory: related to many intelligence measures

Intelligence likely involves a general factor ('g') with subtypes that cluster together
Definitions of intelligence differ across cultures and are influenced by education