Average IQ in Illinois: Estimates & Context
Estimated Avg IQ
~100
US Ranking
#22
of 50 states
Region
Midwest
Note: No state administers IQ tests to its residents. These estimates are proxy conversions from standardized achievement scores (NAEP, SAT, ACT) — an approach popularized by McDaniel's 2006 state-IQ estimates in the journal Intelligence — combined with demographic data. Proxy conversions carry real limitations: SAT/ACT participation rates differ sharply by state and bias comparisons, and the variation within any state dwarfs the differences between states. Figures are shown rounded; decimal precision would overstate what these proxies can support. They say nothing about any individual resident.
About Illinois's IQ Ranking
Illinois sits right at the national average, reflecting the contrast between Chicago's world-class university system and knowledge economy and the state's rural downstate communities. The University of Chicago, Northwestern, and the University of Illinois are all top research institutions. Chicago's finance, technology, and professional services sectors attract educated workers, but the state also has significant poverty concentrations.
What Shapes Illinois's Cognitive Profile
For years Illinois ran the most regressive school funding system in America, with wealthy districts outspending poor ones by wider margins than anywhere else, until the 2017 evidence-based funding formula began narrowing the gap. The University of Illinois Urbana-Champaign produces among the most computer science and engineering graduates of any US campus, but a majority leave the state, a brain drain Chicago's tech scene only partly stems. Two national laboratories, Argonne and Fermilab, sit in the western suburbs and employ thousands of physicists and engineers. Chicago's selective enrollment high schools, including Walter Payton and Northside Prep, rank among the strongest public schools in the country, coexisting with neighborhood schools serving deep poverty a few miles away. Repeated census estimates of population decline skew the remaining population older. Downstate, attainment in counties south of Springfield resembles neighboring Kentucky more than Chicagoland. The estimated state average balances these opposing weights almost exactly at the national mean.
For global context, see how the US compares in our United States IQ page and the full country rankings.
Illinois vs Other Midwest States
| State | Average IQ | US Rank |
|---|---|---|
| Illinois | ~100 | #22 |
| Minnesota | ~104 | #5 |
| Iowa | ~103 | #8 |
| Wisconsin | ~103 | #10 |
| North Dakota | ~103 | #10 |
| Nebraska | ~101 | #15 |
| South Dakota | ~101 | #15 |
| Kansas | ~102 | #16 |
| Ohio | ~100 | #24 |
| Michigan | ~99 | #25 |
| Missouri | ~100 | #26 |
| Indiana | ~99 | #27 |
Frequently Asked Questions
What is the average IQ in Illinois?
Illinois' estimated average IQ is 100.1, essentially the national average, ranking #22. Chicago's educated workforce is balanced by more modest educational outcomes in rural areas.
How does Chicago affect Illinois' ranking?
Chicago is a double-edged sword — its universities and professional class raise the average, but concentrated poverty in South and West Side neighborhoods pulls it down. Suburban Chicagoland generally scores well above average.
How does Illinois compare to other Midwest states?
Illinois (100.1) lags behind Minnesota (103.7) and Wisconsin (102.9) but leads Indiana and Ohio. The northern Midwest states generally outperform the lower Midwest.
Explore Other States
Take our free IQ test to see how you compare, or learn what IQ actually measures.
MyIQScores Editorial Team
Editorial team focused on cognitive testing & psychometrics research
Last updated
May 10, 2026
MyIQScores content is written and maintained by our editorial team using published research in cognitive psychology and psychometrics as its source base. We label estimates as estimates, link primary sources where available, correct errors when readers flag them, and update pages as research or feedback warrants — see our corrections policy.