Why 100 Is Always the Average IQ (By Design)

Here's something that might blow your mind: the average IQ isn't 100 because that's what most people score. It's 100 because the test is designed to make it 100. Every time.

IQ tests use what's called a normalized scoring system. Test creators periodically recalibrate the questions so that the median score always lands at exactly 100. If everyone suddenly got smarter, they'd make the test harder. The number stays the same; only your position relative to everyone else matters.

The Bell Curve of Brainpower

IQ scores follow a bell-shaped distribution. About 68% of people score between 85 and 115. Roughly 95% fall between 70 and 130. The further you get from 100, the rarer you become.

• Below 70: Intellectual disability (about 2.2% of population)
• 85-115: Average range (68%)
• Above 130: Gifted (about 2.2%)
• Above 145: Genius-level (less than 0.1%)

That 140 number often thrown around for "genius" is a bit of a myth. Most psychologists consider 130+ to be gifted, with true genius-level beginning around 145-150.

The Flynn Effect: We're All Getting Smarter

Here's where it gets weird. Raw IQ scores have been rising for decades—about 3 points per decade since the 1930s. This is called the Flynn Effect, and it means your grandparents would score lower on today's test than they did on theirs.

But remember how tests get recalibrated? That's why. If we used 1930s standards, the average person today would score around 115. Instead, we keep moving the goalposts so 100 stays average.

Scientists still debate why scores keep climbing. Better nutrition, more education, greater familiarity with testing, and even video games have all been proposed as explanations.

What IQ Actually Measures (And What It Doesn't)

IQ tests measure specific cognitive abilities: pattern recognition, working memory, processing speed, and verbal comprehension. They're reasonably good at predicting academic success.

What they don't measure is equally important:

• Creativity and artistic ability
• Emotional intelligence
• Practical problem-solving
• Wisdom and judgment
• Motivation and persistence

Einstein, often cited as the ultimate genius, never actually took an IQ test. The "160" number attributed to him is a posthumous estimate. Meanwhile, plenty of people with verified ultra-high IQs have lived unremarkable lives.

The Takeaway

Your IQ score is really just a snapshot of how you performed on one specific test compared to others who took it. The "average" of 100 is a mathematical construction, not a natural constant. And "genius" is more of a cultural label than a scientific threshold.

So if you've ever worried about your IQ, remember: the entire system is designed to make most of us feel average. That's literally the point.