The World’s Shortest IQ Test Shows If You’re Smarter Than 80% Of The Population In Just 3 Questions
Developed by an MIT professor, the 'world's shortest IQ test' is just three questions long.
@_notjustjosh / TikTok The Cognitive Reflection Test (CRT), touted by many as the world's shortest IQ test, is garnering attention anew on the internet.
This quick IQ test purportedly shows that you are smarter than 80% of the population.
Introduced in 2005 by former MIT Professor Shane Frederick (who is now teaching at Princeton), this quick IQ test is just three questions long and seeks to distinguish the intellectual outliers, claiming to measure if one's intelligence outstrips 80% of the global populace.
After introducing the test in a TikTok video, Josh proceeded to present the trio of seemingly simple yet deceptive questions which have confounded many since their conception.
There are just three questions in the CRT IQ test.
The first of which is, "A bat and a ball cost a dollar and $0.10 in total. The bat costs $1 more than the ball. How much does the ball cost?" Seems easy enough! Josh clarified that you are not alone if you've heard of this riddle before. This test has been around for a while, and the questions have spread around the internet before.
The second one is, "If it takes five machines five minutes to make five widgets, how long does it take 100 machines to make 100 widgets?"
The final question also includes numbers, "In a lake, there's a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long does it take for the patch to cover half of the lake?"
Cognitive Reflection Test answers explained
TikTok user Nathan Kennedy, known for his financial advice, provided the much-anticipated CRT answers and explanations behind them. As he guided viewers through each question, he revealed the pitfalls many encounter with these seemingly simple questions.
To the first question, Kennedy states the correct answer to be $0.05, contrary to the initial guess of $0.10 by many. Second, he affirmed that 100 machines would indeed create 100 widgets in 5 minutes, maintaining the same efficiency of one machine per widget.
"The answer is still 5 minutes. That's because each machine pumps out one widget in 5 minutes, so if you have 100 of them, it's still going to take 5 minutes to punch out all of them at the same time," he said.
Lastly, the time needed for the patch of lily pads to cover half the lake would be 47 days, not the intuitive 24 days. Kennedy's revealing insights into the questions highlighted the test's effectiveness in causing test takers to question their initial assumptions.
Is a quick IQ test a reliable measure of one's intelligence?
The answer may not be straightforward. The CRT is designed to divert individuals from their instinctual, intuitive thinking by presenting trick questions.
However, its popularity online may have diluted its effectiveness as an accurate metric of cognitive reflection. This concern was reflected in a 2016 study published in the National Institutes of Health (NIH), which cited the "low reliability" of the CRT. This is due in large part to its online ubiquity. Many individuals encountering the test are likely already familiar with the questions, their answers, or at least the general logic behind them.
As such, while the CRT continues to fascinate and challenge new audiences, its capacity as an accurate gauge of cognitive abilities is still up for debate.
Ethan Cotler is a writer and frequent contributor to YourTango living in Boston. His writing covers entertainment, news, and human interest stories.