Data & Rankings
Chart-led pieces on how scores are distributed across countries, states, ages, jobs and education levels — always with the caveats attached.
What Is the Smartest Breed of Cat? Why No Ranking Exists
Dogs have a famous intelligence order, a vote by 199 obedience judges. Cats have none: no study has ranked cat breeds on a cognition test. The largest breed survey, 5,726 cats, measured ten behaviour traits and not one of them was cognition.
What Is the Smartest Animal in the Ocean? Octopus, Dolphin and Orca Compared
No study tests whales, dolphins, octopuses and fish on the same task. Each famous result rests on very few animals: 2 dolphins in a mirror study, 1 orca copying sounds, 4 marked fish. By cortex neurons, the pilot whale leads with 37.2 billion.
Smartest European Country? PISA, Adult Skills and IQ Estimates
Estonia ranks first in Europe on PISA 2025, and Finland ranks first on adult skills and on national IQ estimates. Across 23 European countries the school and adult rankings barely agree, and the IQ estimates rest on small and uneven samples.
Smartest Dog Breeds Ranked: Coren's Order and What It Measures
The famous list of the smartest dog breeds is a vote by 199 obedience judges, not an IQ test. The Border Collie, Poodle and German Shepherd lead it, and a 2022 Science study found that breed explains just 9% of behavioural variation between dogs.
Chess Players Ranked by IQ: Every Number Traced to Its Source
Almost no top chess player has a published IQ test. Of 11 we checked, one has a reported magazine test, one a reported school test, and one a stream quiz. The 190s trace to no test; one website’s rating formula gives 191 for Anand.
Founding Fathers Ranked by IQ: What Cox's 1926 Estimates Show
Six Founding Fathers have IQ-style estimates, all from one 1926 study of historical records. Jefferson (153.8) and Franklin (152.5) lead on the average of its four numbers, Washington (132.5) is last, and none of them took a test.
World Leaders Ranked by IQ (2026): The Only Estimates, Degrees and Hoax Lists
No sitting world leader has a published IQ score. The only IQ-style numbers cover 85 historic leaders in a 1926 study and 42 US presidents; for everyone else, the checkable record is a degree, not a score, and the viral lists trace to hoaxes.
UK Prime Ministers Ranked by IQ: The Only Estimates, Degrees and Expert Rankings
No British prime minister has a published IQ test score. The only IQ-style numbers cover six historic prime ministers, from a 1926 study of eminent people; degree classes are a weak stand-in; and historians rank success, not intelligence.
Average IQ of Lawyers: What the LSAT, Bar Exam and Army Data Show
Nobody has measured the average IQ of lawyers today. The popular 128 comes from a 1945 Army test scored on a scale with a standard deviation of 20, which is about 121 on today's scale. The LSAT and the bar exam are published, and neither has an IQ equivalent.
Average IQ by Country 2026: South Korea Leads at 106.97, Rankings and Limits
South Korea leads the International IQ Test's 2026 country table at 106.97. The table's own sample counts show a quarter of the 1,212,714 test-takers came from Indonesia, that the rows do not average to the stated 100, and that scores track the size of each country's crowd.
PISA 2025 Results: Record Lows, and What They Do Not Show About IQ
The OECD average fell to 463 in mathematics and 461 in reading, the lowest it has recorded. A 22-point maths fall works out at about three points on an IQ-style scale, but that is a unit conversion, not a measurement of anyone's intelligence.
Average IQ of Pilots and Air Traffic Controllers: What Data Exist
We found no representative IQ survey of pilots or air traffic controllers. What exists is a 50-person Indian Air Force sample with a mean full-scale IQ of 114.26, an FAA statement from 1974, published selection cut-offs and validity studies, and none of it gives a single average.
How Many Words Does the Average Person Know? About 42,000 at Age 20
The best-documented answer is about 42,000 lemmas for an average 20-year-old native English speaker, from only 11,100 word families. The number changes with what you count, and vocabulary is among the most g-loaded parts of an IQ test.
Midwit Meme Explained: The IQ Bell Curve, Its Origin and the Real Numbers
The IQ bell curve meme is built on a real shape: IQ scores are scored to follow it. What it claims about the people on it is a joke format, not a finding, and the word "midwit" first meant someone above average. Here are its origin, the real percentages and what each part of the joke gets wrong.
Do Billionaires Have Higher IQs? What the Swedish Data Shows
A 2023 study matched Swedish military conscription test scores to wage records and found that cognitive ability rises with income only up to a point. Above that point, the top 1 percent of earners score slightly lower than the bracket just below them.
Average IQ by US State: All 50 States, and What the Numbers Rest On
No state has a measured average IQ. Here are all 50 states from the most-copied table, built from 2005 school tests, beside the same arithmetic on 2024 data: half of its top ten and half of its bottom ten have changed, and the spread between typical states is about two points.
IQ and Political Party: What US Survey Data Actually Shows
Surveys going back to the 1970s tie vocabulary-test scores to party identification. The gap is small, mostly explained by education and income, concentrated in verbal ability specifically, and has partly reversed since the 1980s.
US Presidents Ranked by IQ: All 42 Estimates, and the Trump and Obama Gap
One peer-reviewed study estimated the IQ of every president from George Washington to George W. Bush. It put John Quincy Adams first at 168.8 and Ulysses S. Grant last at 120. No president was ever given an IQ test for it, and the ranges overlap far more than a ranked list suggests.
Average IQ by Occupation: What the 1940s Army Data Shows
Nearly every "IQ by profession" chart online traces to one 1945 study of wartime enlisted men, scored on a scale that modern IQ tests do not use. Here is what that table shows and what still holds up.
Twin Studies and IQ Heritability: How Much of Intelligence Is Genetic?
In 11,000 twin pairs the heritability of IQ rose from 41% at age 9 to 66% at 17, and identical twins reared apart correlate .72 in the pooled 1981 review. Heritability is a population statistic, and DNA-based studies find less than twin studies do.
The Same Model, Two Labs, Different Scores: Why AI Benchmarks Disagree
OpenAI and Anthropic published figures for the same rival models within four days of each other. They do not match, and the reasons are the ones psychometrics named a century ago.
The Relative Age Effect: Youngest in Class Scores Lower
Two children born eleven months apart can land in the same school year, and the younger one reliably tests lower on cognitive and achievement measures for reasons that have nothing to do with ability and mostly fade by adulthood.
Average IQ by Education Level: The Arrow Points Both Ways
Tables ranking average IQ by degree level circulate constantly and are read as though schooling simply sorts people. Pooled longitudinal evidence puts the correlation at about 0.56, and a meta-analysis of more than 600,000 people found that education also raises scores.
Does IQ Predict Income? The Link Explains About 5 Per Cent
The meta-analytic correlation between measured intelligence and earnings is around 0.23, which leaves roughly ninety-five per cent of the differences in pay to everything else. A 2026 analysis of two large US cohorts adds a second finding: your specific strengths carry a third to a half of the weight that general ability does.
How Rare Is an IQ of 130? The Curve Says 1 in 44, Not 1 in 50
On a mean-100, standard-deviation-15 scale, 130 sits at the 97.72nd percentile, which leaves about one person in 44 above it. Here is the rarity at every threshold — and why the figures stop describing real people long before they stop being calculable.
Country IQ Rankings Are Weaker Than the Charts Suggest
The tables that circulate as national IQ figures come from one compilation built out of whatever studies existed, in whatever years, on whatever samples. Several of the numbers were estimated rather than measured.
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Every number carries its scale
An IQ figure is meaningless without the scale it was measured on and the range around it. Every story here reports all three, or says plainly that the source did not.
Sources are listed, not implied
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