Articles
Explainer articles on IQ and cognitive ability.
Fluid vs Crystallized Intelligence: How the Two Differ by Age
A clear look at fluid intelligence (Gf) vs crystallized intelligence (Gc), framed by CHC theory and how each changes with age. The power to solve new problems versus accumulated knowledge, explained without exaggeration.
2026-06-09
How to Build Logical Thinking: Deduction, Induction & Daily Practice
How to develop logical thinking. We cover the difference between deduction and induction, practice with visual logic tasks, and daily habits, without exaggeration.
2026-06-08
How to Train Spatial Reasoning: Boosting Mental Rotation in Daily Life
How to train spatial reasoning (mental rotation). We share practice with shapes and everyday habits, while honestly noting the limit: large gains in overall IQ are unlikely.
2026-06-07
IQ Tests for Children: What Age, and WISC vs. Quick Tests
Basics of children's IQ tests (WISC and more): from what age they can be taken, the difference between testing at a clinic and online quick tests, and the link to gifted education, explained without exaggeration.
2026-06-06
What Percentage Has an IQ of 140? Top ~0.4%, Explained
An IQ of 140 is roughly the top 0.4%, or about 1 in 260 people. We explain its rarity, how it differs from IQ 130, and its honest relationship to giftedness using distribution data.
2026-06-05
EQ vs IQ: What's the Difference, and Which Matters More?
A clear, honest look at the difference between EQ (emotional intelligence) and IQ. IQ reflects cognitive ability such as fluid reasoning, while EQ is about recognizing and regulating emotions—complementary, not ranked.
2026-06-04
Is Average IQ by Country Reliable? The Limits Explained
Are 'average IQ by country' rankings actually correct? We honestly review the sampling and cultural bias problems in Lynn et al.'s research, why you shouldn't take the numbers at face value, and the myths about national rankings.
2026-06-03
How to Convert Between IQ and Deviation Score: Formula and Chart
How to convert between IQ (mean 100, SD 15) and the deviation score (mean 50, SD 10). Covers the conversion formula, a quick chart, and worked examples like IQ 130 equals a deviation score of 70.
2026-06-02
Are Celebrity and Genius IQs Real? Why the Numbers Don't Hold Up
Most "celebrity IQ" and "genius IQ" figures you see online are estimates of unknown origin. Almost no one has officially released their own score, and standards differ by era and test method. Here's an honest explanation of why.
2026-05-31
What Is the WAIS? The Difference Between Formal IQ Tests and Free Online Tests
The WAIS is one of the leading IQ tests for adults. We explain in plain terms how it differs from the WISC and the Binet scales, and why free online tests are estimates rather than clinical diagnoses.
2026-05-28
Is IQ Linked to Income? The Strength of the Correlation and Key Caveats
An honest look at the relationship between IQ and income. Research shows moderate correlations with academic and job performance and earnings, but we lay out, without exaggeration, that correlation is not causation and that many factors are involved.
2026-05-25
What Does "Gifted" Mean? A Clear Look at Its Link to IQ and Its Many Sides
We define what gifted means, explain why an IQ of 130 or above is often used as one benchmark, and cover 2e (twice-exceptional) and the many-sided nature of giftedness, all without exaggeration.
2026-05-22
How to Join Mensa: The Top 2% Requirement and the Testing Process
A clear guide to joining Mensa. We lay out the top 2% requirement (roughly IQ 130 and above), the typical process for accepted prior tests and supervised admission tests, and how to think about the steps involved.
2026-05-19
What Are the Traits of People With High IQ? Research-Backed Tendencies and Caveats
A research-based look at the traits of high-IQ people. We cover tendencies like fast learning and abstract thinking, while honestly explaining why a high IQ does not guarantee success or define personality.
2026-05-16
What Is the g Factor? A Plain-Language Guide to General Intelligence and CHC Theory
What does psychology mean by the "g factor" (general intelligence)? From Spearman's discovery to CHC theory, we lay out the structure of intelligence in clear, accessible terms.
2026-05-12
How to Train Your Working Memory: 5 Everyday Methods
Can working memory really be trained? We introduce five everyday training methods, including the n-back task and chunking, that you can easily incorporate into daily life.
2026-05-09
How to Solve Matrix Reasoning Problems: Spot the Rule in 3 Steps
For anyone who struggles with matrix reasoning problems, this guide explains a 3-step method—checking rows, columns, and relationships in order—using worked examples.
2026-05-06
What Percentage Has an IQ of 130? Top X% and How Rare It Is
An IQ of 130 puts you in roughly the top 2%, about 1 in 50 people. We explain how rare an IQ of 130 is, often cited as the gifted threshold, along with its traits and the underlying distribution data.
2026-05-03
What Is the Average IQ? The Basics of Standard Deviation and Distribution
The average IQ is 100 and the standard deviation is 15. We explain in plain terms why 100 is the average, the shape of the distribution, and how to think about "top X%."
2026-05-01