Intelligence (Chapter 9, p ) Lecture Outline : History of intelligence IQ and normal distributions Measurement and Theory

Two Views of Intelligence n Psychophysical n RT, sensitivity to physical stimuli n Galton (1883) and later Cattell (1890) proposed psychophysical tests measured ability n Contribution: Psychometrics, measurement of traits and processes n Mental judgement n Memory, vocabulary, and perceptual discrimination n Binet & Simon (1904) diagnosed “mental defectives” in Paris n Contribution: Testing and IQ

Definition of Intelligence An inferred characteristic usually defined as the ability to profit from experience, acquire knowledge, think abstractly, act purposely, and adapt to changes in the environment.

What is an Intelligence Quotient? n IQ = (MA / CA) X 100 n MA = Mental age, CA = Chronological age n 8 year old with MA of 12 has IQ of 150 n Problem across life span. MA may not differ much from age 25 to 50, but IQ of someone 50 is not half that of a 25 year old n Problem with different variability at each age

Intelligence tests and IQ n Goal directed adaptive behavior n IQ tests define a domain of skills necessary to succeed in school What is the goal? What is the environment being adapted to? Original Purpose: Identify “slow learners” and bring them up to speed

Measuring intelligence

Assessing intelligence n Stanford Binet- Revised: n Short-term memory, Verbal, Quantitative, and Figural Abstract Reasoning n Wechsler Scales: n Verbal, Performance, and Total IQ scores n WAIS-III, WISC-III, WPPSI n Most commonly used intelligence test today

Interpretation of performance n Standardized testing conditions: we assume that temperature, lighting, vision, hearing does not impact performance n Lack of motivation and performance anxiety can detract from performance –If you think you will fail or are stressed out, performance decreases –Mastery, positive stereotypes, confidence enhances performance n Low motivation interferes with high IQ n Right answer (psychometric) and strategies used when solving problems (cognitive)

Potential for cultural bias in IQ tests n What is The Bluenose? n Who was Thomas Jefferson?

Validity: Example of SAT n Face validity: Does the test make sense? n Predictive validity: Does it predict Acadia grades? n Concurrent validity: Were they related to Grade 12 grades? n Construct validity: Does the SAT measure the construct it is supposed to measure?

Definitions n Aptitude: Ability to learn in a specific area n Achievement: What is already learned in an area n Psychometric: Psychological measurement n Metacognition: Understanding and control of thought processes

Spearman’s Model

Multiple intelligences? Spatial in athletes, mechanics Musical genious Emotional intelligence and empathy

Triarchic Theory of Intelligence Transferring skills to new situations e.g., setting up a DVD player Componential Information- processing strategies, metacognition e.g., long division Experiential Contextual Practical applications of intelligence, knowing when to change, adapt, or fix your environment e.g., getting to Halifax

Normal curve of IQ scores

Extremes of intelligence n Mental Retardation is at low end n Dx when IQ and adaptive behavior is low n Mild n Moderate n Severe n Profound <25 n Gifted at high end n 1% have IQ > 135 n Terman’s longitudinal study documenting “success” of men with IQ >140, but those with low motivation underachieved n School programming n Mensa: IQ 130 or 98th percentile