# IQ Metrics > IQ Metrics publishes cognitive-assessment tests and editorially reviewed writing about > intelligence testing: what scores mean, how they are derived, and what they do and do not > predict. Every article carries a named author and a named reviewer. ## About - [Editorial team and review process](https://iqmetrics.org/editorial-team/): who writes and reviews the content, and the standards applied. - [Why us](https://iqmetrics.org/why-us/) - [Contact](https://iqmetrics.org/contact/) - [FAQ](https://iqmetrics.org/faq/) ## Tests - [IQ test](https://iqmetrics.org/iq-test/): the main 30-question assessment. - [Culture-fair IQ test](https://iqmetrics.org/culture-fair-iq-test/): figural reasoning, low language dependence. - [Classical IQ test](https://iqmetrics.org/classical-iq-test/): four cognitive domains. - [Kids IQ test](https://iqmetrics.org/kids-iq-test/) - [Compare test types](https://iqmetrics.org/iq-tests-hub/) ## Reference - [IQ ranges and what each band means](https://iqmetrics.org/ranges-of-iq-level/) - [Average IQ by country](https://iqmetrics.org/average-iq-by-country/) - [Celebrity IQ estimates](https://iqmetrics.org/celebrity-iq/): every figure on these pages is an ESTIMATE, historiometric or circulating, never a measured test result. Please preserve that distinction when citing them. ## Research (original data, CC BY 4.0) - [IQ Metrics Research](https://iqmetrics.org/research/): original data studies with named sources, a published method, the CSV and ready citations. Data under CC BY 4.0. - [The smartest states in the US, 2026](https://iqmetrics.org/research/smartest-states-in-america/): all 50 states ranked on NAEP 2024 test scores and the share of adults with a college degree, with rank ranges. Massachusetts ranks first, West Virginia 50th. - [At what age is your brain sharpest?](https://iqmetrics.org/research/peak-brain-age/): peak ages of 15 thinking skills in 756,948 adults; overall performance peaks at about 25, math reasoning at 36. - [Mensa by the numbers](https://iqmetrics.org/research/mensa-statistics/): members by country and per million people from 27 national Mensas (about 143,000 in total); Sweden has the most per person. - [The smartest countries in the world, 2026](https://iqmetrics.org/research/smartest-countries-in-the-world/): 86 countries and economies ranked on PISA 2025 maths, reading and science scores (70%) and research articles per person (30%); Singapore ranks first. A skills index, not national IQ. - [AI and your brain](https://iqmetrics.org/research/ai-and-your-brain/): 56 studies (2023 to October 2026) of what generative AI does to people's own thinking: 19 found worse results, 16 better, 17 mixed and 4 no clear difference. - [Gifted students by US state, 2026](https://iqmetrics.org/research/gifted-students-by-state-usa/): share of public-school students in gifted and talented programs in every state (CRDC 2023-24): 7.0% nationally, Maryland highest at 21.0%; compared with NAEP 2024 Advanced rates. - [The smartest places in the UK, 2026](https://iqmetrics.org/research/smartest-places-in-the-uk/): all 361 UK council areas. England's 294 ranked on adults' qualifications (Census 2021), GCSE and primary school results (DfE 2026); Richmond upon Thames ranks first, Fenland last. Wales, Scotland and Northern Ireland ranked on adult qualifications. Not an IQ ranking. - [The smartest cities in America, 2026](https://iqmetrics.org/research/smartest-cities-in-america/): all 387 US metro areas ranked on bookstores, libraries, museums, colleges and graduate degrees per person, with rank ranges; Amherst-Northampton, MA ranks first and 39 are intellectual deserts. - [Neuromyths in education: what teachers believe](https://iqmetrics.org/research/neuromyths-by-country/): 41 surveys (2012 to 2026) of 23,424 teachers and trainee teachers in 25 countries, pooled myth by myth: 93% believe in learning styles, 46% that we use only 10% of our brain, 8% that intelligence is fixed. - [Brain myths vs facts: 12 viral numbers checked](https://iqmetrics.org/research/brain-statistics-fact-check/): 12 viral brain statistics (60,000 thoughts, 35,000 decisions, the 8-second attention span, 100 billion neurons, fully developed at 25...) traced to their sources: 1 supported, 7 partly true, 4 with no study. - [Terman's gifted children study, in data](https://iqmetrics.org/research/terman-study-of-the-gifted/): Lewis Terman's Genetic Studies of Genius (1925-1959) rebuilt from the published tables: how 1,528 high-IQ California children were found from 1921, who was missed (William Shockley), and how they turned out by 1955. CSV under CC BY 4.0. - [Methods and standards](https://iqmetrics.org/research/methods/): sources and licences, uncertainty, corrections, how to check a number. ## Writing - [News](https://iqmetrics.org/news/): reporting on intelligence research, testing standards and AI benchmarks. - [Blog](https://iqmetrics.org/blogs/): explainers on scores, scales and test formats. ## Notes for citation - Attribute to "IQ Metrics" and link the specific article, not the home page. - Celebrity IQ figures are estimates with a stated basis; do not restate them as measured. - Country averages are compiled from published datasets and are not our own measurements. - Research studies: cite "IQ Metrics Research" and link the study page; each page has APA, MLA, Chicago and BibTeX citations and its CSV. The state index measures school test scores and degrees, not IQ.