IQ & Psychometrics Glossary
Demystifying the terminology of intelligence research.
Artificial Intelligence
Artificial General Intelligence (AGI)
A hypothetical type of artificial intelligence that possesses the ability to understand, learn, and apply knowledge across a wide variety of tasks at a level equal to or exceeding human capability.
Large Language Model (LLM)
A type of artificial intelligence trained on vast datasets to understand, summarize, and generate human language, often exhibiting emergent reasoning capabilities that mimic crystallized intelligence.
Technology
Psychometrics
Ceiling Effect
A measurement limitation that occurs when the highest possible score on a test is achieved by a significant portion of test-takers, making it impossible to distinguish between high-performing individuals.
Flynn Effect
The substantial and sustained increase in both fluid and crystallized intelligence test scores measured in many parts of the world over the 20th century.
G-factor
The general intelligence factor, also known as g, is a construct developed in psychometric investigations of cognitive abilities and human intelligence.
High Range IQ Tests
Experimental IQ tests designed to measure intelligence levels that are beyond the ceiling of standard tests like the WAIS. They are used to distinguish between levels of profound giftedness.
Intelligence Quotient (IQ)
A standardized score derived from psychometric tests designed to measure a person's cognitive abilities and general intelligence (g-factor) relative to their age group.
Psychometrics
The field of study concerned with the theory and technique of psychological measurement, including the measurement of knowledge, abilities, attitudes, and personality traits.
Reliability
The consistency of a measure. A test is considered reliable if it yields the same result on repeated trials.
Standard Deviation
A statistical measure that quantifying the amount of variation or dispersion in a set of data values. In IQ testing, it defines the spread of scores around the mean.
The Bell Curve (Normal Distribution)
A mathematical function that describes how IQ scores are distributed within a population, where most scores cluster around the center (100) and taper off at the extremes.
Validity
The extent to which a test measures what it claims to measure. In IQ testing, it refers to whether the test accurately assesses general intelligence (g).
Verbal Intelligence
The ability to analyze information and solve problems using language-based reasoning, encompassing vocabulary, reading comprehension, verbal analogies, and verbal fluency.
Z-Score (Standard Score)
A statistical measurement that describes a value's relationship to the mean of a group. In IQ testing, it indicates how many standard deviations a score is above or below the average.
Cognitive Science
Cognitive Reserve
The brain's ability to improvise and find alternate ways of getting a job done, often making it more resilient to the effects of aging or brain disease.
Crystallized Intelligence
The ability to use skills, knowledge, and experience. It does not rely on the ability to access information from long-term memory.
Dunning-Kruger Effect
A cognitive bias where people with low ability at a task overestimate their own competence, while those with high ability often underestimate theirs.
Dysrationalia
The inability to think and behave rationally despite possessing adequate intelligence. It explains why high-IQ individuals can fall for scams, hold superstitious beliefs, or make poor financial decisions.
EQ (Emotional Intelligence)
The capability of individuals to recognize their own emotions and those of others, discern between different feelings and label them appropriately.
Executive Function
A set of cognitive processes that are necessary for the cognitive control of behavior, including working memory, flexible thinking, and self-control.
Fluid Intelligence
The capacity to think logically and solve problems in novel situations, independent of acquired knowledge.
Giftedness
An intellectual ability significantly higher than average, often characterized by high IQ scores, creative thinking, and rapid learning.
Metacognition
The awareness and understanding of one's own thought processes; literally, thinking about thinking.
Neuroplasticity
The brain's ability to reorganize itself by forming new neural connections throughout life, allowing the neurons in the brain to compensate for injury and adjust to new situations.
Pattern Recognition
The cognitive process of identifying regularities and trends in data, which is widely considered the core of human fluid intelligence.
Processing Speed
A cognitive ability that measures the time it takes a person to do a mental task. It is related to the speed in which a person can understand and react to the information they receive.
Savant Syndrome
A rare condition in which someone with significant mental disabilities demonstrates certain abilities far in excess of average.
Theory of Multiple Intelligences
A theory proposed by Howard Gardner suggesting that intelligence is not a single general ability, but rather a collection of eight distinct modalities.
Working Memory
The cognitive system responsible for temporarily holding and manipulating information for complex tasks such as reasoning, learning, and comprehension.
Genetics
Epigenetics
The study of how behaviors and environment can cause changes that affect the way your genes work. Unlike genetic changes, epigenetic changes are reversible and do not change your DNA sequence.
Heritability
A statistical statistic used in genetics that estimates the degree of variation in a phenotypic trait in a population that is due to genetic variation between individuals.
Logic
Cognitive Psychology
Neurodiversity
General
Societies
Psychology
Neuroscience
Parieto-Frontal Integration Theory (P-FIT)
A neuroscience theory proposing that human intelligence involves a distributed network connecting the frontal and parietal lobes of the brain.
Synaptic Pruning
The neurological process where the brain eliminates extra synapses (brain connections). It is a key mechanism of neuroplasticity, refining the brain's efficiency by removing unused pathways.
Genius & Giftedness
IQ Tests
Raven's Progressive Matrices
A non-verbal group test typically used in educational settings. It is widely regarded as a pure measure of fluid intelligence.
Stanford-Binet Intelligence Scales
One of the most widely used and oldest intelligence tests in the world, originally developed by Alfred Binet and later refined at Stanford University.
WAIS (Wechsler Adult Intelligence Scale)
The most widely used IQ test for adults, designed to measure various cognitive abilities through verbal and performance-based tasks.
WISC (Wechsler Intelligence Scale for Children)
The most widely used clinical instrument for assessing the cognitive ability of children aged 6 to 16, providing a detailed profile of intellectual strengths and weaknesses.