A standardized battery of tasks yields a score that compares an individual’s cognitive performance to age-matched norms. An IQ test is that instrument. Modern tests assess verbal comprehension, perceptual reasoning, working memory, and processing speed.

Scores are scaled so that the population mean is 100 and the standard deviation is 15. IQ tests are among the most carefully constructed and validated tools in psychology. They predict school achievement and, to a lesser extent, occupational status. They are not pure measures of innate potential; performance reflects education, cultural familiarity, and test-taking conditions as well as cognitive ability.

Responsible use requires attention to the test’s limits, the confidence interval around any single score, and the individual’s broader context. Controversies over bias, high-stakes decisions, and the reification of the score continue. When used judiciously, IQ tests supply useful information about current cognitive strengths and weaknesses.

• Standardized measure of intellectual performance
• Yields scores relative to age norms
• Predicts academic and some occupational outcomes
• Must be interpreted within broader context