Intelligence

Intelligence is the ability to:
- Learn from experience
- Solve problems
- Use knowledge to adapt to new situations

Two-factor theory:
- Proposes a general intelligence factor, known as the “g” factor.
Sternberg’s triarchic theory:
- Analytical intelligence: Problem-solving abilities.
- Creative intelligence: Ability to deal with novel situations.
- Practical intelligence: Application of skills in real-world contexts.
Gardner’s multiple intelligences:
- Types include:
  - Verbal
  - Mathematical
  - Spatial
  - Bodily-kinesthetic
  - Musical
  - Interpersonal
  - Intrapersonal
  - Naturalist

Moderate correlation (around +0.40) between brain volume and intelligence.
Brain size decreases with age, and verbal intelligence test scores also decline.

Graph overview showing probability distribution of IQ scores ranging from 60 to 140.

Alfred Binet developed an early test to predict children’s future performance in the Paris school system.

Standardized tests produce a normal distribution of scores known as the normal curve or bell-shaped pattern.

Optimal IQ tests ideally focus solely on aptitude but may reflect some achievement.
Improvements on Binet's test:
- Raymond B. Cattell: Culture-free testing.
- Wechsler: WISC (Wechsler Intelligence Scale for Children) and WAIS (Wechsler Adult Intelligence Scale).
- Raven’s Progressive Matrices: Test based on pattern recognition without a language component.

Higher IQ correlates with higher education levels, which contribute to professional success.

Fluid intelligence: Ability to think quickly; peaks in early adulthood.
Crystallized intelligence: Accumulated knowledge; increases into late adulthood.

Acceptable psychological tests must meet:
1. Standardization
2. Reliability
3. Validity

Process of administering a test to a representative sample to create benchmarks for comparison.

Reliability: Consistency of test results.
Validity: Extent to which a test measures what it is intended to measure; reliability alone does not ensure validity.

Evidence from twins, familial studies, and adopted children show both genetic and environmental contributions to intelligence.

Schooling experiences are reflected in intelligence scores; more schooling correlates with higher childhood intelligence scores.

Over the past century, average intelligence scores have risen by approximately 30 points.
Represents a significant societal trend in cognitive performance.

Concerns regarding performance based on negative stereotypes can affect individuals' test outcomes.
Documented in various studies related to historically discriminated groups.