Authoritative guides on IQ testing, scoring methodology, careers, and our product.
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.
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.
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.
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.
Why working memory caps expert performance, what the deliberate-practice meta-analyses show, and what to train when more reps stop working. The science.
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.
Forced-rank quotas downgrade high performers and lift their voluntary exit hazard 34% at 18 months. Here's what the research says, and what to do next.
Decade-by-decade IQ data from Hartshorne, Salthouse, Schaie, and Singh-Manoux shows no single peak age. See which abilities decline, hold, or rise after 45.
The Cognitive Demand Index maps IQ by occupation across 100 US jobs using O*NET reasoning data and BLS 2025 wages. See where brain power and pay diverge.
National IQ averages vary dramatically, but the data is more contested than most sources admit. Here's what the science shows, and what it means for you.
What a pre-employment cognitive test looks like from the employer's side: what your score report shows, how cut scores and ranges work, and your ADA rights.
Every IQ score is a range, not a fixed number. Learn what Standard Error of Measurement means, why scores shift, and how to read your confidence interval.