Everything about IQ, explained honestly
In-depth guides on what IQ scores actually mean, how tests work, what the research supports, and where the popular myths go wrong.
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IQ Score Guide: every score from 55 to 160
Percentile, classification, and rarity for every IQ score - plus detailed guides for specific scores. Start here to find what your score means.
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What Was Einstein's IQ? The Number With No Source
Einstein never took an IQ test, and the 160 everyone quotes has no traceable source, not even the 1926 study people assume. Here's the full provenance.
Does IQ Actually Matter? What It Predicts and What It Doesn't
IQ predicts job performance less than textbooks claimed (about 0.31, below structured interviews) and lifespan more than most realise. What the data shows.
What Is the Highest IQ Ever Recorded?
The highest recorded IQ is 228, a ratio score from a ten-year-old in 1956. Guinness retired the category in 1990, and every larger figure is unverified.
Is IQ Genetic? What Twin Studies Actually Show
About 80% of the variation in adult IQ tracks genetic variation, and the genetic share grows with age while the family home stops mattering. What it means.
What IQ Is Considered Genius? The Number Nobody Agrees On
There is no official genius IQ. The 140 everyone quotes comes from one row in a 1916 book, using a formula dropped in 1939. No modern test uses the label.
Does IQ Change With Age? What Actually Happens Over a Lifetime
Your IQ score barely moves across a lifetime, but the abilities behind it change: processing speed peaks in your early 20s, vocabulary climbs until 65-70.
Can You Improve Your IQ? What the Research Actually Says
Yes, but modestly. Education adds 1-5 IQ points per year, exercise and sleep help, and brain-training apps mostly don't. What the research supports.
How to Join Mensa: Qualifying Scores, Accepted Tests, and the Process
Mensa requires the 98th percentile: IQ 130 on Wechsler, 132 on older Stanford-Binet. Accepted tests, the US and UK process, fees, and what members get.
How Accurate Is an IQ Score? What Measurement Error Actually Means
Professional IQ tests have reliability of 0.95+, but every score carries a ±5 point margin. How to read your confidence interval and why scores change.
IQ vs EQ: What's the Actual Difference?
IQ measures cognitive ability; EQ measures emotional and social skill. They correlate only weakly. What each one predicts, and which matters more for what.
What IQ Do You Need for Different Jobs?
None, for any of them. No profession has an IQ requirement; quoted averages show who got through a filter. What the data shows and what gates entry.
Average IQ by Country, Age, and Profession: What the Data Actually Says
Average IQ across countries, age groups and professions, and which of these comparisons are methodologically sound and which are internet folklore.
IQ and Autism: Why the Test You Take Changes the Answer
Autistic children in one study scored 30 percentile points higher on Raven's than on Wechsler, with no gap in controls. That's a finding about the tests.
IQ and ADHD: Why the Score Understates You
ADHD lowers two of the four indexes behind Full Scale IQ, so the composite understates reasoning. Most adults with ADHD score higher on a corrective index.
Are IQ Tests Legal for Hiring?
Yes, conditionally. The conditions come from Griggs v Duke Power (1971): a test must measure the person for the job. That still shapes how the world hires.
Are IQ Tests Biased? What the Word Means in Psychometrics
Two different questions get called bias, and research answers only one. Well-built tests aren't predictively biased, which settles less than people think.
IQ Tests for Children: Which Test, What Age, and What the Score Means
Testing is possible from about age 2.5 but meaningful years later. Which test suits which age, when a score is stable, and how gifted screening works.
How Accurate Are Online IQ Tests?
Well-designed online IQ tests land within about 10-15 points of a clinical assessment. Badly designed ones are essentially random. How to tell them apart.
What Is a Good IQ Score? A Complete Breakdown by Percentile
A good IQ score is typically 110 or above, putting you in the top 25%. The full percentile breakdown, what each IQ range means, and where you rank.
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