Articles on intelligence, reasoning and how IQ tests like ours are made and scored.
LatestHow IQ tests work
Abstract reasoning means finding the rule behind patterns you have not seen before. What it is, everyday and test examples, how it relates to fluid intelligence and IQ, and why the UCAT dropped its section.
IQ and emotional intelligence are measured in very different ways. What each score means, how much they overlap, what research says each predicts at school and work, and where the popular EQ numbers come from.
The Wechsler Adult Intelligence Scale, now Pearson's WAIS-5 from 2024, is a one-to-one clinical IQ test. What changed from the WAIS-IV, what it costs, and why a free online WAIS quiz is not the real test.
The Stanford-Binet Intelligence Scales, Fifth Edition (Roid, 2003) is a one-to-one clinical IQ test with 10 subtests and five factors (PRO-ED). How it is given and scored, and why online quizzes differ.
A full IQ test such as the WAIS-5 (Pearson, 2024) samples five abilities and combines them into one score. Raven's matrix test uses a single type of item (APA task force, 1996).
Raven's Progressive Matrices are nonverbal reasoning tests in which you pick the piece that completes a pattern. Scores are compared with an age-based norm group, and the test uses only one kind of puzzle.
Calculated from the WAIS-5's 0.97 reliability (2024), a clinical IQ score has a 95% range of about 5 points either side. Online tests vary, and most free quizzes publish no data.
Fluid intelligence is the ability to reason and solve new problems without relying on what you already know (PNAS, 2008). Learn how it differs from crystallized intelligence and how it is measured.
The average IQ is 100 because tests are scored that way: the norming sample's mean is set to 100 and the standard deviation to 15 (APA, 1996). Learn what the score bands and their labels mean.
24 puzzles, about 15 minutes, a short warm-up first.
