Learn about IQ & intelligence
Plain-English guides to IQ scores, scales, percentiles and what the research actually says — so you know exactly what your results mean.
What Is the Average IQ? Scores by Age, Country and What They Mean
The average IQ is 100 by definition. See how IQ scores are distributed, what counts as above or below average, and how age and country affect the numbers.
Read the guide →What Is a Good IQ Score? Ranges, Percentiles and Context
Is 110 a good IQ? What about 120 or 130? See the full IQ classification table, what each range means in practice, and why context matters more than the number.
Read the guide →The IQ Scale Explained: What Every Range Means
A clear walkthrough of the IQ scale from below 70 to above 145 — how the bell curve works, what each classification label means, and where most people fall.
Read the guide →IQ Score Chart: Classifications and Percentiles at a Glance
A complete IQ score chart showing every range, its classification label, the share of the population in it, and the matching percentile — with plain-English explanations.
Read the guide →IQ Percentiles: What Your Score Means Compared to Everyone Else
Convert any IQ score to a percentile: an IQ of 115 beats 84% of people, 130 beats 98%. Full conversion table plus how percentiles are calculated.
Read the guide →Average IQ by Age: How Scores Are Adjusted Across a Lifetime
IQ is age-normed, so the average is 100 at every age — but raw cognitive abilities rise and fall across life. See how fluid and crystallized intelligence change by decade.
Read the guide →The Highest IQ Ever Recorded: Records, Claims and Reality
From Marilyn vos Savant's Guinness record to William James Sidis and modern claims — what the highest recorded IQ scores really are and why extreme scores are hard to measure.
Read the guide →How to Increase Your IQ: What Science Actually Supports
Can you raise your IQ? What research says about brain training, education, sleep, exercise and practice effects — and how much improvement is realistic.
Read the guide →How IQ Tests Work: Questions, Scoring and What They Measure
What's actually inside an IQ test? Matrix reasoning, norming samples, deviation scoring and standard error — how a set of puzzles becomes a score of 100.
Read the guide →Cognitive Ability Tests: Types, Uses and How to Prepare
Cognitive ability tests measure reasoning, memory and processing speed — used in hiring, education and self-assessment. Here's what they cover and how to prepare.
Read the guide →The 9 Enneagram Types Explained: Which One Are You?
A clear guide to the nine Enneagram personality types — core motivations, fears, strengths and growth paths — plus how the Enneagram compares to trait-based tests.
Read the guide →Type A vs Type B Personality: Traits, Myths and the Research
Driven and deadline-focused, or relaxed and flexible? What Type A and Type B actually mean, where the theory came from, and what modern research says.
Read the guide →How to Make a Career Change: A Practical, Evidence-Based Guide
Thinking about changing careers? A step-by-step framework: assess your interests and strengths, test-drive options, manage the finances and make the switch.
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