Articles

Plain-English writing about IQ, cognition, and how the numbers are actually calculated.

• What is an IQ test? A plain-English guide

  IQ tests measure reasoning ability across a few core domains. Here's what they actually measure, what they don't, and how the score is calculated.

  6 min read · Updated 2026-06-01

• Average IQ by age: what actually changes over time

  IQ scores are age-normed, so the average is 100 at every age. What actually changes with age is fluid vs crystallised ability — here's the difference.

  5 min read · Updated 2026-06-01

• How IQ tests are scored: from raw answers to a 3-digit number

  The path from your raw answers to an IQ score involves a norming sample, a bell curve, and a bit of statistics. Here's what happens step by step.

  7 min read · Updated 2026-06-01