World's shortest IQ test has just three questions — see if you're smarter than 80% of the people

Psychologists, educators, and curious minds all across the world have been trying to explore the potential of human intelligence for a very long time. What started as a way to assess academic ability has developed into a flexible tool that is used in diverse fields. Once limited to classrooms, IQ tests are now used by firms as well, and the cognitive reflection test (CRT) sticks out as an innovative method among them. It boldly claims that three very simple questions may determine whether you are a genius, making it the shortest IQ test in the world.

In 2005, Princeton psychologist Shane Frederick created a brain teaser designed to separate snap judgments from thoughtful reasoning. This clever test challenges the mind to slow down and think critically instead of looking for instant answers. Its purpose is to test cognitive strength through psychometric scores. As reported by My Modern Met, this test isn’t just about right or wrong answers; it’s a window into the mechanics of the human mind. As reported by GOOD, the three mind-boggling questions of the test include, "A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?" Although it may seem pretty simple, it still confuses people.

The second question is, "If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?" The third one is, "In a lake, there is 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 would it take for the patch to cover half of the lake?" These explore the idea of exponential growth in depth. "5 cents", "five minutes", and "47 days" are the correct responses to the questions respectively. Despite its apparent simplicity, each answer requires a more complex level of reasoning. In his YouTube video, Dr. Lyndon Walker, a former finance and statistics lecturer, explains the solutions in detail.

The solutions are also thoroughly explained in the blog Mind Your Decisions by Presh Talwalkar, author of 'The Hoy of Game Theory: An Introduction to Strategic Thinking.' Not just this, financial advisor Nathan Kennedy also explores the Cognitive Reflection Test in one of his videos on TikTok. He reveals the correct responses and also draws attention to the mental traps that these difficult questions might set up. His explanations will surely help people spot common errors and develop critical thinking skills.

Meanwhile, over 3,000 people from a wide range of educational backgrounds were invited to take the test by Professor Frederick during his research. It also included students from prestigious universities like Yale and Harvard, who were unable to crack it. Shockingly, just 17% of participants correctly answered each of the three questions. It demonstrated that even the most brilliant minds are susceptible to its misleading simplicity, as reported by The Mirror. 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."