What Is IQ? Meaning, Measurement, and Modern Testing

IQ (intelligence quotient) is a standardized score intended to summarize general cognitive performance across reasoning, problem-solving, working memory and pattern recognition. A single number can never capture the full range of human intelligence, but a well-constructed test gives a useful, repeatable snapshot of how someone performs on structured cognitive tasks.

Modern IQ tests convert raw performance on several subtests into scaled scores, then combine those into index scores and a single Full Scale IQ. The scale is anchored to a reference mean of 100 and a standard deviation of 15, so most people score somewhere between 85 and 115.

An IQ estimate reflects performance on a specific set of tasks on a specific day. It says little about creativity, motivation, emotional skill, practical judgement or long-term potential. Online estimates are not clinical evaluations and should never be used for diagnosis, placement or employment decisions.

A clinical intelligence test is administered one-on-one by a trained psychologist using standardized materials and conditions. An online test like TESTUNO is a structured self-administered estimate — useful for curiosity and self-insight, but not equivalent to a clinical evaluation.