IIF Certified Assessment
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IIF Certified Assessment
A reasoning puzzle every day with the full working shown, plus honest coverage of what brain-training products can and cannot do.
A bad night does not lower intelligence. It reliably lowers the things a timed test happens to measure most closely — sustained attention, working memory and speed — while leaving vocabulary and general knowledge comparatively intact.
The sturdiest results are narrow and decades old. The 2025 studies that drew the headlines rest on self-reports and small preprints — and none of them measured intelligence at all.
Two people can perform identically on two different online tests and walk away with scores twenty points apart. The scale, the comparison group and the margin of error are what separate an assessment from a quiz.
An IQ figure is meaningless without the scale it was measured on and the range around it. Every story here reports all three, or says plainly that the source did not.
Each story ends with the studies, datasets and documents it draws on, named and attributed, so you can go and read them yourself.
Spotted an error? Write to corrections@iqmetrics.org. Corrections are made on the story and noted at the bottom of it — never quietly.
Our IIF-certified assessment reports your score with its scale, percentile and confidence range — and a breakdown of the cognitive domains behind it.
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