Data & Rankings
Chart-led pieces on how scores are distributed across countries, states, ages, jobs and education levels — always with the caveats attached.
How Many Words Does the Average Person Know? Vocabulary Size and IQ
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.
The IQ Bell Curve Midwit Meme: What It Gets Right and Wrong
The bell curve in the midwit meme is real: IQ scores are built to follow one. What the meme claims about the people on it is a joke format, not a finding, and the arithmetic shows why.
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: What the Numbers Rest On
No state has a measured average IQ. The popular tables convert school test scores from 2005 into IQ points, the spread between typical states is about two points on that scale, and the poverty gap inside one state is bigger than the whole map.
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: Where the Numbers Come From
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 80-Year-Old Army Data Actually Shows
Nearly every "IQ by profession" chart online traces to one 1945 study of wartime enlisted men, scored on a scale that is not even the one modern IQ tests use. Here is the real table — and what still holds up.
Twin Studies and IQ: What the Correlation Data Actually Shows
Identical twins raised in separate homes end up more alike on IQ than fraternal twins raised in the same one. That single, replicated pattern is the whole logic behind how heritability gets estimated — and behind why the number is so often misread.
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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