'World's shortest IQ test' says a lot with three questions and just 17% pass it

'World's shortest IQ test' says a lot with three questions and just 17% pass itMIT professor Shane Frederick's Cognitive Reflection Test is a three-question brain teaser with only a 17 per cent pass rate - can you beat the odds and solve all three?CommentsNewsKieran Isgin Money & Lifestyle writer, Courtney Pochin Lifestyle Editor and Chloe Dobinson14:25, 13 Apr 2026View 2 ImagesAn IQ test is a great way to measure your knowledge (Image: seksan Mongkhonkhamsao via Getty Images)IQ tests are a useful and straightforward method of measuring your intelligence.‌Typically, these assessments can be rather lengthy, running for over an hour with a wide range of questions designed to push your mind to its absolute limits. Despite this, many bright sparks may be astonished to discover that there exists an IQ test comprising just three questions.‌Yet, the brevity of the test doesn't make it any easier to crack. In fact, research revealed that a mere 17% of participants managed to pass the brainteaser.‌Known as the Cognitive Reflection Test, the quiz originally featured in a research paper published in 2005 by MIT professor Shane Frederick. Since resurfacing on the internet, the paper has gone viral as people scramble to find out whether they can conquer the "world's shortest IQ test".As part of the study, Professor Frederick had more than 3,000 participants from a variety of educational backgrounds complete the IQ test. Of that sizeable group, only 17% succeeded in scoring three out of three.Speaking about the test, Professor Frederick, said: "The three items on the CRT are 'easy' in the sense that their solution is easily understood when explained, yet reaching the correct answer often requires the suppression of an erroneous answer that springs 'impulsively' to mind".‌What are the questions?View 2 ImagesOnly 17 per cent of participants managed to pass this brain teaser(Image: Kohei Hara via Getty Images)...