IQ (Intelligence Quotient)
A standardized score derived from cognitive tests designed to measure general intellectual ability, with 100 as the population average.
IQ tests measure a blend of fluid intelligence (novel problem-solving) and crystallized intelligence (accumulated knowledge). The average is 100 with a standard deviation of 15 — so about 68% of people score between 85 and 115. IQ correlates with academic success, job performance, and even longevity. But it doesn't measure everything that matters: creativity, emotional intelligence, practical problem-solving, leadership, artistic ability, and domain expertise all fall outside traditional IQ tests. The number also isn't as fixed as people assume. IQ is partially heritable (about 50-80% in adulthood) but responds to education, environmental enrichment, and cognitive engagement. The Flynn effect — the observation that average IQ scores have risen 3 points per decade for a century — proves that intelligence at the population level is not static.
Frequently Asked Questions
Can you increase your IQ?
Your IQ score can change. Education, cognitive engagement, and environmental enrichment all influence IQ — especially in childhood and adolescence, where interventions show the largest effects. In adults, the evidence for increasing IQ through cognitive practice is more modest, but processing speed and working memory improvements can lift performance on IQ subtests. The Flynn effect proves intelligence is not fixed at the population level.
What does IQ not measure?
Creativity, emotional intelligence, practical problem-solving, social skills, motivation, grit, artistic ability, musical talent, leadership, moral reasoning, and domain-specific expertise. IQ captures one dimension of human cognitive ability — a useful one, but far from the complete picture. Many of the skills that determine real-world success are not measured by traditional IQ tests.