Intelligence: Historical Perspectives

Historical Perspectives on Intelligence

• Sir Francis Galton and Alfred Binet are foundational figures in the study of intelligence.
• Galton (1822 - 1911) believed genius was hereditary and conducted physical/sensory measurements on eminent families to support his theory.
• Measurements included reaction speed, hand strength, sensory acuity, and skull size, though predictive power was poor.
• In the 1920s, South Africa established the Eugenics and Genetics Standing Committee, promoting racial categorization and oppression.

Alfred Binet's Contributions

• Binet (1857 - 1911) aimed to create an objective intelligence test for schoolchildren, leading to the first workable intelligence test in 1905.
• His method involved testing large groups of children, establishing norms based on average scores, and comparing individual performance to these norms.
• The concept of mental age (MA) was introduced, noting faster learners often answered questions like older children.

Intelligence Quotient Development

• William Stern expanded on Binet's concept, introducing the intelligence quotient (IQ) formula: IQ = (MA/CA) x 100.
• This ratio allowed for comparisons across different ages.
• The Stanford-Binet Test, revised by Lewis Terman, focused on verbal skills and established a common measure in clinical psychology and educational counseling.

Wechsler's Intelligence Scales

• David Wechsler (1896 - 1981) criticized the Stanford-Binet for its reliance on verbal skills, proposing alternative measures through WAIS-R, WISC-IV, and WPPSI-R.
• Wechsler introduced three main IQ components: Verbal Scale IQ, Performance Scale IQ, and Full Scale IQ, allowing a more comprehensive view of intelligence.

Structure of WISC-IV

• The WISC-IV consists of four cognitive domains that contribute to Full Scale IQ through subtest scores.
• Subtests for verbal comprehension include similarities, vocabulary, and comprehension.

South African Intelligence Tests

• The Senior South African Individual Scale (SSAIS-R) and Junior South African Individual Scale (JSAIS-R) assess verbal and non-verbal performance.
• The South African Wechsler Adult Intelligence Scale (SAWAIS) serves adults aged 16-69 years.

Approaches to Understanding Intelligence

• Two primary approaches: Psychometric (mapping structure and competencies) and Cognitive Processes (studying thought processes underlying intelligence).

Psychometric Approach

• Psychometrics involves statistical analysis of psychological tests.
• Factor analysis reduces a large number of measures to clusters of correlated variables.

The ‘g’ Factor

• Charles Spearman (1923) proposed that intelligence comprises a general factor (‘g’) and specific abilities (‘s’).
• The ‘g’ factor is a strong predictor of academic and job performance.

Horn-Cattell's Theory

• Distinguishes between crystallized intelligence (gc) - knowledge and skills acquired, and fluid intelligence (gf) - problem-solving abilities and creativity.
• gc generally improves with age, while gf tends to decline in late adulthood.

Multiple Intelligences Theory

• Howard Gardner's theory suggests eight intelligences, including linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, intrapersonal, naturalistic, and existential.

Emotional Intelligence

• Emotional intelligence encompasses skills such as reading and responding to emotions, self-motivation, self-awareness, and emotion regulation.
• The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) assesses emotional competence, including perceiving, using, understanding, and managing emotions.