IQ Lab pairs carefully constructed cognitive tests with a plain-language guide to a century of intelligence research - what IQ measures, what it predicts, and what it can't tell you.
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Original items in the formats with the strongest research pedigree - figural matrices, verbal and quantitative reasoning, mental rotation, and digit span.
A 16-item screener across four cognitive domains. Ideal for a first estimate.
Start quick test40 items across five domains, including an interactive working-memory task. A tighter, more reliable estimate with a detailed domain profile.
Start full testNumbers from the peer-reviewed literature - each one sourced on our Science page.
IQ scores are scaled to a normal distribution with mean 100 and standard deviation 15. Drag the slider to see how any score compares to the population.
A century of research, summarized honestly - including the parts that complicate the story.
The g factor, how modern tests are built, and why so many different mental tasks correlate.
What twin, adoption, and DNA studies show - and why "heritable" doesn't mean "fixed."
Education, work, health, and longevity - the real effect sizes, without hype.
Why average scores rose for decades, what it says about environment, and recent reversals.
What IQ tests miss, historical misuse, and how to interpret a score responsibly.
Education, brain training, nutrition, sleep - which interventions hold up in trials.