What IQ is, how IQ tests work, the history and science of intelligence measurement.
22 articles
Working memory holds and manipulates information for seconds at a time. Its real capacity is about four chunks — not seven — it correlates with fluid intelligence at r ≈ .72, and it forms one of the four index scores behind your WAIS IQ.
The Wechsler Adult Intelligence Scale is the world's most used adult IQ test. Its editions, index scores, the General Ability Index — and why independent researchers reject the WAIS-5's five-factor structure.
The Cognitive Reflection Test answers are 5 cents, 5 minutes and 47 days. Why the intuitive answers fail, what your score means, and whether knowing the answers really invalidates it.
Cognitive tests fall into three unrelated categories. How clinical screens like the MoCA and MMSE differ from IQ tests, what the scores mean, and why the 26/30 cutoff misleads.
Ability tests, trait questionnaires and mixed models measure different things. How the MSCEIT is scored, why self-report EI is mostly personality, and why there is no EQ score.
There are no left-brained or right-brained people — 1,011 brains and 14 million connections found none. What is genuinely lateralised, and what Sperry warned about.
Fluid intelligence solves novel problems; crystallized intelligence applies what you know. Why one declines with age and the other keeps rising into your sixties.
Inhibition, working memory and cognitive flexibility. The unity-and-diversity framework, the task impurity problem, and why lab tasks and rating scales correlate at only .19.
Processing speed peaks before any other cognitive ability. Salthouse's theory of cognitive ageing, inspection time and IQ, and why a low speed score is not a low ability.
