What America's Numeracy Slide Could Cost Each Worker
US adult numeracy fell 6 points on the 2023 PIAAC survey. See how that modeled decline maps to roughly $1,300 to $2,100 a year in per-worker wage exposure.
Resource Library
Resource Library
Authoritative guides on IQ testing, scoring methodology, careers, and our product.
Is a Gifted IQ Score Reliable? The Math Says 1 in 4 Won't Repeat
A gifted IQ score of 130 feels like a verdict, yet the reliability math expects more than 1 in 4 one-shot labels to regress below the line on a retest.
Does IQ Predict Job Performance? A Shrinking Number
Cognitive ability still predicts job performance, but the corrected correlation fell from r = .51 in 1998 to r = .22 in 2024. See what shrank and what held up.
The Best Age to Peak by Profession: A Cognitive-Gap Table
There is no single peak age. See how 10 professions map onto the abilities that peak at 19, 25, or the late 60s, and why experience offsets raw-speed decline.
IQ by Medical Specialty: Which Doctors Score Highest
Dermatology tops the specialty score ranking, but the gap is just 0.87 of one exam SD and no validated USMLE-to-IQ conversion exists. The data, decoded.
IQ 130 Careers: Where high cognitive ability meets $140k+ pay
Only 5 occupations clear both the high-cognitive-demand bar and the $140k+ BLS mean-wage bar. A four-source synthesis of what IQ 130 buys you in 2026.
Working Memory Is the Ceiling: Why Deliberate Practice has Limits in Adult Careers
Why working memory caps expert performance, what the deliberate-practice meta-analyses show, and what to train when more reps stop working. The science.
IQ Test Career Recommendations: What They Predict, and the Limits in 2026
We audited 7 popular IQ-to-career tools against published validity evidence. Only 1 of 7 disclosed a coefficient. Here is what the field's research says.