AP Psychology Unit 2 (Cognition): Understanding Intelligence and Psychological Testing

Intelligence

Capacity to learn from experience, solve problems, and use knowledge to adapt to new situations; inferred from performance patterns rather than directly observed.

IQ (intelligence quotient)

Score from a standardized test designed to assess human intelligence; best interpreted as relative standing in a norm group, not a measure of worth or fixed potential.

Deviation IQ

Modern IQ scoring approach that compares a person’s performance to others in the same age group rather than using a mental-age ratio.

Standard IQ scaling (mean 100, SD 15)

Common IQ scale where the average score is 100 and the standard deviation is often 15, allowing interpretation of how far scores fall from the average.

Standardization

Process of administering a test to a large, representative sample and using the results to set consistent procedures and establish reference points for interpreting scores.

Norms (norm group)

Reference data from a representative sample that define what counts as typical performance and allow raw scores to be interpreted meaningfully.

Normal distribution (bell curve)

A distribution pattern many IQ tests are designed to approximate, with most scores clustering near the mean and fewer scores at the extremes.

z-score

Statistic showing how many standard deviations a score is above or below the mean (z = (X − μ)/σ); can be converted to IQ on a mean-100, SD-15 scale (IQ = 100 + 15z).

Stanford-Binet

Modern intelligence test descended from Alfred Binet’s work; originally developed to identify children who needed educational support and based on skills that typically develop with age.

Wechsler scales (WAIS/WISC)

Widely used intelligence tests (adult and child versions) that report an overall Full Scale IQ plus index scores across domains (e.g., verbal comprehension, working memory, processing speed).

Achievement test

Test that measures what a person has learned (e.g., a final exam).

Aptitude test

Test designed to predict future performance (e.g., likely success in a training program), though scores are influenced by prior learning opportunities and context.

Reliability (test-retest, split-half, inter-rater)

Consistency of a measure: test-retest (stability over time), split-half (agreement between two halves of a test), and inter-rater (agreement among different scorers). Reliability does not guarantee accuracy.

Validity (content, criterion-related, construct)

Extent to which a test measures what it claims and supports appropriate interpretations/uses: content (covers relevant skills), criterion-related (predicts outcomes), construct (measures the intended psychological construct rather than something else).

Flynn effect

Observed rise in average performance on intelligence tests across generations, suggesting environmental influences on test performance (e.g., education, nutrition, familiarity with abstract reasoning).

General intelligence (g)

Spearman’s idea of a shared factor inferred from positive correlations among diverse cognitive tasks; a statistical pattern, not a single “brain module.”

Thurstone’s primary mental abilities

Theory proposing multiple distinct ability areas (e.g., verbal comprehension, numerical ability, spatial ability, perceptual speed), emphasizing an ability profile rather than one general factor.

Gardner’s multiple intelligences

Theory proposing several relatively independent intelligences (e.g., linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, intrapersonal, naturalistic); influential in education but criticized for limited psychometric validation as “intelligences.”

Sternberg’s triarchic theory

Model describing intelligence as analytic (academic problem-solving), creative (novel idea generation/adaptation), and practical (real-world application/“street smarts”).

Emotional intelligence

Ability to perceive, understand, manage, and use emotions effectively in oneself and others (e.g., recognizing emotions, regulating anxiety, using empathy in communication).

Fluid intelligence

Capacity to reason and solve novel problems independent of specific learned knowledge (often linked to speed and new problem-solving).

Crystallized intelligence

Accumulated knowledge and verbal skills built from education and experience (e.g., vocabulary, learned facts).

Test bias (in psychological testing)

When a test measures something systematically differently for different groups, leading to invalid or unfair interpretations; group score differences alone do not prove bias.

Cultural bias

Bias that occurs when test items assume knowledge, experiences, or language patterns more familiar to one cultural group, making scores partly reflect cultural exposure rather than the intended ability.

Stereotype threat

Situational pressure where fear of confirming a negative stereotype increases anxiety and self-monitoring, diverting attention/working memory and lowering performance despite unchanged ability.