IQ scores explained: what the numbers mean
Short, plain answers to the questions people ask about IQ scores, each with a sample question from the test.
Are online IQ tests accurate?What makes an IQ test accurate, why most quick online quizzes are not, and how to recognise one that gives a usable estimate.
Fluid vs crystallized intelligence: what is the difference?The two broad abilities behind every IQ score: what each one is, how they change across life, and which parts of a test measure which.
How is IQ calculated?From correct answers to an IQ score: the formula, the norm group behind it and why every result comes with a margin of error.
IQ scale: what IQ score ranges meanEvery IQ band from below 70 to above 145, with the label, the share of adults and the percentile behind each score.
IQ tests for kids: a guide for parentsFor parents: at what age testing makes sense, how a proper assessment works, what online tests can and cannot say, and when to ask the school.
What IQ is considered genius?The usual thresholds for gifted and genius, where the 140 figure comes from, and why modern tests no longer use the word.
What is a good IQ score?Where "good", "high" and "very high" begin on the IQ scale, and how to read a score that sits between bands.
What is IQ? What IQ stands for and what it measuresWhat the letters mean, where the score came from, what an IQ test actually measures and what it leaves out.
What is matrix reasoning?The pattern-grid puzzle at the heart of most IQ tests: what it measures, where it comes from and the handful of rules behind nearly every item.
What is the average IQ?The short answer, the normal range for adults, and why the average stays at 100 at every age.
What is the highest IQ ever recorded?What the top of the scale really is, where the famous 200-plus figures come from, and why no one can honestly hold the record.
What kind of questions are on an IQ test?The six main item types used in IQ tests, what each one measures and a worked example of every kind.