Pay People to Take IQ Tests and They Get Smarter

Here's an uncomfortable truth about one of psychology's most famous measurements: IQ scores are for sale. Not through cheating or bribery, but through something far simpler—just offering people a few dollars to do well.

A landmark 2011 meta-analysis published in the Proceedings of the National Academy of Sciences examined decades of research on intelligence testing. The finding that made psychologists squirm? Material incentives substantially improved IQ test performance, with average gains of nearly 10 points in some studies.

The Motivation Problem

Think about the last time you took a standardized test. How hard did you really try? If you're like most people, the answer is "hard enough"—whatever that means. You probably didn't treat it like your life depended on the outcome.

But what if someone offered you $100 for every point you scored above average? Suddenly those pattern recognition questions seem worth a second look. That mental arithmetic deserves a double-check.

This is exactly what researchers found. When participants had something tangible to gain, they:

• Spent more time on difficult questions
• Double-checked their answers more frequently
• Showed greater persistence on challenging problems
• Maintained focus throughout the entire test

What IQ Tests Actually Measure

The implications are profound. IQ tests don't purely measure some fixed cognitive capacity—they capture a messy combination of ability, motivation, test-taking skills, and how much you care about the outcome.

This helps explain some long-standing puzzles in intelligence research. Why do IQ scores predict success so well? Perhaps because the same people who try hard on a pointless test also try hard at school and work. The test measures conscientiousness as much as cognitive horsepower.

The Stakes Matter

Here's where it gets interesting. The incentive effect was strongest among people with lower baseline scores. Those who initially scored in lower ranges showed the biggest jumps when money was on the line.

This suggests that "low IQ" scores might often reflect low motivation rather than low ability. When disadvantaged populations score lower on IQ tests, we might be measuring their (entirely rational) skepticism that the test matters—not their intelligence.

Consider a teenager taking an IQ test for a research study. They get nothing either way. Compare that to a student taking the SAT knowing it determines their college admission. Same underlying ability, wildly different effort.

The Dark Implication

We've built enormous social structures around IQ and similar tests. Schools track students. Employers filter candidates. The military assigns roles. All based on scores that fluctuate depending on whether someone ate breakfast or got promised a gift card.

The researchers put it bluntly: using IQ scores to predict life outcomes without accounting for motivation is like measuring someone's height while they're sitting down. You'll get a number, but you're missing crucial information.

So the next time someone brags about their IQ score, you might ask: "How much were they paying you?"