Writing
Honest writing about testing and thinking
No hype, no borrowed authority, no claims we cannot support. If the evidence is thin, we say so. A new article goes up every week.
September 6, 2026 · G. Factor · 6 min read
Fluid vs. Crystallised Ability: Unpacking Two Core Aspects of Cognition
Explore the fundamental differences between fluid and crystallised intelligence, how they evolve throughout life, and why reasoning tests primarily measure the ability to solve novel problems rather than accumulated knowledge.
Read the article
March 17, 2026 · G. Factor · 8 min read
Can you improve your cognitive performance? An honest answer
Brain-training claims outrun the evidence. What actually seems to move measured performance, what only moves your test score, and how to tell whether a change in your result is real.
Read the article
February 24, 2026 · G. Factor · 9 min read
Are free online IQ tests accurate?
Some are informative, most are theatre. A practical guide to telling the difference — the warning signs, the honest signals, and how accurate an unsupervised online test can realistically be.
Read the article
February 3, 2026 · G. Factor · 7 min read
How adaptive testing works, and why it needs fewer questions
Adaptive tests choose each question based on how you answered the last ones. Here is why that produces a tighter estimate in half the questions — and where the approach has real limits.
Read the article
January 14, 2026 · G. Factor · 8 min read
What IQ scores actually mean (and what they don't)
An IQ score is a position in a distribution, not a quantity of intelligence. Here is how the 100-average scale works, what a percentile really tells you, and the decisions a score should never be used for.
Read the article
Try the free test
The free short test takes about 8 minutes and your result appears the moment you finish.
No card required. No email needed to see your first score.