Intelligence: Assessment and Theories

The chapter discusses intelligence in depth, including its assessment and history.
Intelligence tests trace back to early 20th century, specifically during WWI.

Types of Tests:
Intelligence tests: Measure overall mental aptitude.
Achievement tests: Assess what individuals have learned.
Aptitude tests: Predict future performance (e.g., SAT).
Correlation between intelligence tests and academic success is noted, indicating a strong relationship with formal educational skills.

Francis Galton:
Related to Darwin; first to study intelligence through reaction times.
Developed the correlation coefficient.
Controversially linked to eugenics, advocating for reproductive policies based on intelligence scores.
Alfred Binet:
Created the first intelligence test for placing children in appropriate educational settings.
Introduced the concept of mental age, determining placement based on cognitive performance rather than labeling intelligence.
Lewis Terman:
Developed the Stanford-Binet test, adapting Binet's work for an American audience and including adults.
Used as a screening tool during WWI; led to some controversial implications regarding immigration and military service.

Intelligence Quotient (IQ):
Originally defined as mental age divided by chronological age multiplied by 100.
Represents a ratio reflecting cognitive capability, although problematic in adulthood.
Average IQ score historically set around 100, with a standard deviation of 15.

WAIS (Wechsler Adult Intelligence Scale):
Most widely used adult intelligence test comprising four categories:
- Verbal Comprehension: Assesses similarity, vocabulary, and reading comprehension.
- Perceptual Reasoning: Evaluates spatial reasoning skills.
- Working Memory: Measures memory through tasks like digit span and arithmetic.
- Processing Speed: Assesses speed in tasks such as symbol searching.

Three Criteria:
Standardization: Ensures comparability across demographics.
Reliability: Consistency of test results over time.
Validity: Measures what it intends to measure, which remains debated among researchers.

Definition of Intelligence: Ability to learn from experience, solve problems, and adapt using knowledge. A contested definition.
General Intelligence (g): Proposed by Charles Spearman, suggesting a single underlying general intelligence influences various cognitive skills.
Multiple Intelligences (Howard Gardner): Proposes eight distinct types:
Naturalistic
Spatial
Linguistic
Intrapersonal
Interpersonal
Kinesthetic
Musical
Logical/Mathematical
Existential
Triarchic Theory (Robert Sternberg): Identifies three types of intelligence:
Analytical Intelligence (problem-solving and analysis)
Creative Intelligence (innovative thinking)
Practical Intelligence (application in real-world settings)
Emotional Intelligence: Ability to understand and manage emotions; correlates poorly with traditional IQ measures.

Intelligence changes over the lifespan, with cross-sectional studies suggesting decline with age while longitudinal studies indicate stability or even improvement.
Crystallized Intelligence: Knowledge acquired over time that tends to increase with age.
Fluid Intelligence: Speed of processing and abstract reasoning that often declines with age.

Environment plays a significant role, particularly in impoverished settings, where the development of intelligence can be adversely affected.
Genetic influence on intelligence (heritability) is noted but emphasizes the necessity of a rich environment for genetic potentials to be realized.

Intelligence tests have been shown to exhibit bias against certain cultural and socioeconomic groups.
The historical eugenics movement utilized biased tests to implement harmful reproductive policies.
Ongoing debates about the implications and the necessity of reforming intelligence tests to be more culturally neutral.

Intelligence is profoundly influenced by both genetics and environment, and understanding its assessment and theories remain crucial in psychology today.