Chapter 9: Intelligence and Psychological Testing
Intelligence At least two major "consensus" definitions of intelligence have been proposed. First, from Intelligence: Knowns and Unknowns, a report of a task force convened by the American Psychological Association in 1995: Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person s intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of "intelligence" are attempts to clarify and organize this complex set of phenomena. Although considerable clarity has been achieved in some areas, no such conceptualization has yet answered all the important questions and none commands universal assent. Indeed, when two dozen prominent theorists were recently asked to define intelligence, they gave two dozen somewhat different definitions.[1] A second definition of intelligence comes from "Mainstream Science on Intelligence", which was signed by 52 intelligence researchers in 1994: a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings "catching on", "making sense" of things, or "figuring out" what to do.[2]
Intelligence intelligence is the ability to learn about, learn from, understand, and interact with one s environment. This general ability consists of a number of specific abilities, which include these specific abilities: Adaptability to a new environment or to changes in the current environment Capacity for knowledge and the ability to acquire it Capacity for reason and abstract thought Ability to comprehend relationships Ability to evaluate and judge Capacity for original and productive thought
Principle Types of Psychological Tests Psychological test: standardized measure of a sampleof a person s behavior. -Measure individual differences in abilities, aptitudes, interests, and personality. Mental ability tests Intelligence: general mental abilities intellectual potential. Aptitude: specific types of mental abilities -Ex. abstract reasoning, spelling, numerical ability, etc. Achievement: gauge a person s knowledge of a subject. Personality scales Measure motives, interests, values, and attitudes. Are you introverted, independent, ambitious, assertive?
Key Concepts in Psychological Testing Standardization: uniform procedures applied to admin & scoring of a test. Test norms: where a score ranks in relations to other scores on that test (everything is relative). Standardization group: sample of people that the norms are based on (ideally a large (recent) sample). Reliability: measure of consistency of a test (test-retest reliability). Correlation coefficient: numerical index of degree of relationship. Validity: ability to measure what you say your measuring (accuracy and usefulness of inferences or decisions). Content validity: content reflects intended domain. Criterion-related validity: test scores are validated by an independent measure reflecting the same domain of behavior. Construct validity: look at correlations between test scores on other measures (used mainly with hypothetical construct testing)
Test Retest Reliability
Correlation & Reliability
Criterion-Related Validity
Construct Validity
The Evolution of Intelligence Testing Sir Francis Galton(1869) Genius is Hereditary Developed the statistical concept of correlation & regression Coined the term nature versus nurture Eugenics: social philosophy which advocates the improvement of human hereditary traits through various forms of intervention (meant for good but used for bad (racial discrimination). Pangenesis: gemmules transported in the blood rabbit experiments Alfred Binet and Theodore Simon(1905) Binet-Simon Intelligence Scale: First intelligence test; measured abstract reasoning skills rather than sensory skills (Galton). Mental age: displayed the mental ability typical of a child of that chronological (actual) age. Lewis Terman(1916) Stanford-Binet Intelligence Scale revised Binet scale. Intelligence Quotient (IQ)= MA/CA x 100; childs mental age divided by chronological age multiplied by 100. Can compare children of different ages everyone uses the same scale. David Wechsler(1955) Wechsler Adult Intelligence Scale: less dependent on verbal ability; based scoring on the normal distribution.
The Normal Distribution The Normal Distribution: symmetric, bell-shaped curve that represents the pattern in which many characteristics are dispersed in the population. Deviation IQ scores: locate subjects within the normal distribution using the standard deviation. Mean of distribution set at: 100 Standard deviation (SD): 15
Reliability and Validity of IQ tests Exceptionally reliable correlations into the.90s. Qualified validity valid indicators of academic/verbal intelligence, not intelligence in a truly general sense. Correlations:.40s.50s with school success..60s.80s with number of years in school. Predictive of occupational attainment, debate about predictiveness of performance.
The Flynn Effect The Flynn effect is the trend, all over the developed world, for IQ scores to increase from one generation to the next. Are children smarter? Or are IQ tests a bad measure of intelligence? g = general intelligence factor and is the factor that represents the binding of the components of intelligence. people that excel in one tend to excel on them all; thus we speak of general intelligence or the g-factor g-factor scores have increased dramatically over time, however, subtest scores increases show chaotic variability. At any one time g-factor is reliable; but over time we see intelligence is multiple and social constructs of the time influence subtest scores across time. Today we are better at abstractions, logic and hypothetical thinking.
Multiple Intelligence