If you’ve seen a map ranking every state by IQ this year, here’s the twist: nobody gave those states an IQ test. The figures come from reading and math exams taken by public school fourth and eighth graders, and the newest scores in that original study are from 2005.
So when a “2026 ranking” puts California near the bottom, it’s describing kids who were in elementary and middle school two decades ago.
What is the average IQ in the United States?
The average IQ in the United States is 100, because that’s how IQ tests are built. Test makers “norm” their exams on large samples of Americans and set the middle score at 100, with most people landing between 85 and 115, according to Riot IQ, an online testing company.
That’s also why the number barely moves. If people get better at the tasks over the years, the tests get re-normed and the middle goes back to 100.
Some state-ranking sites show a national figure a little under that. World Population Review, one of the most shared sources, lists 98.0 in its summary, while its own state table shows 100.3. When one page gives you two national averages, that’s your first clue the numbers are estimates.
Where do the state IQ numbers come from?
The best-known state IQ table comes from a 2006 study published in the journal Intelligence (McDaniel, 2006). It didn’t test anyone’s IQ. It took scores from the National Assessment of Educational Progress (NAEP), often called the Nation’s Report Card, and converted them to an IQ-style scale.
Here’s what went into it, according to the paper:
- Who: public school students in grades 4 and 8. Private school, homeschooled and tutored kids weren’t included, because only public school NAEP results are published by state.
- What: reading and math tests, averaged together.
- When: test years from 1990 to 2005.
- Not covered: adults. Nobody’s parents, abuelos or tíos were part of the data.
NAEP is an achievement test. It measures what students know in school subjects, which is not the same thing an IQ test tries to measure.
Now compare that with the viral rankings. World Population Review’s table, updated in October 2026, puts Massachusetts first at 104.3, New Hampshire at 104.2 and Mississippi last at 94.2. Those are the exact figures in the 2006 study’s table, along with California at 95.5 and New Jersey at 102.8. A New Jersey radio station’s website recently presented that same 102.8 as part of a state IQ ranking for 2026.
Why California, Texas and Arizona land where they do
If your familia lives in one of the states with the biggest Latino populations, the viral map may have stung a little. In the 2006 table, California sits at 95.5, New Mexico at 95.7, Arizona at 97.4, Florida at 98.4 and Texas at 100.0.
Before you take that personally, look at what the number actually measures: public school test averages from about 20 years ago. A few things the study itself points out:
- The private school gap pulls scores down. The author writes that leaving out private and homeschooled students likely makes state estimates lower than they really are, and that gap is bigger in some states than others.
- Exclusions vary by state. States set their own rules for which students sit out the test, so the samples aren’t perfectly comparable.
- Test prep can skew things. The paper notes Texas had documented coaching on its own state tests.
The paper also doesn’t say how students who were still learning English were handled. For a bilingual reader, that’s a fair question to ask about any test of reading taken in English.
So next time a state IQ map pops up in the family group chat, ask one question before anyone argues: who took the test, and when? Then tell us in the comments what your state’s ranking got wrong.
