The world's shortest IQ assessment, comprising just three questions, can accurately determine whether you possess greater intelligence than eighty percent of the global population. Known as the Cognitive Reflection Test (CRT), this brief examination was originally developed in 2005 but has recently experienced a remarkable resurgence in popularity across social media platforms.
The Viral Phenomenon of a Three-Question Challenge
Created by psychologist Shane Frederick, currently affiliated with the Yale School of Management, the CRT was specifically designed to predict an individual's susceptibility to common cognitive errors in reasoning and decision-making processes. Despite its minimal length, this test has demonstrated significant predictive power regarding reflective thinking capabilities.
One particular TikTok user's detailed explanation of the three questions has amassed an astonishing fourteen million views, propelling the decades-old assessment back into the public consciousness. The test's viral success highlights our enduring fascination with measuring intellectual capacity through seemingly straightforward challenges.
The Deceptive Simplicity of Three Questions
All three CRT questions appear remarkably simple at first glance, yet they consistently prove surprisingly difficult for most test-takers. The questions involve calculating the price of a bat and ball, determining manufacturing times for widgets, and calculating the growth rate of lily pads in a lake.
The first question presents this scenario: A bat and ball together cost $1.10. The bat costs exactly $1.00 more than the ball. How much does the ball cost?
The second question asks: If five machines require five minutes to manufacture five widgets, how long would one hundred machines need to produce one hundred widgets?
The final question challenges: In a lake, a patch of lily pads doubles in size each day. If the patch completely covers the lake after forty-eight days, how many days would it take to cover half the lake?
Why These Questions Prove So Challenging
The Cognitive Reflection Test operates on a clever psychological principle: each question presents an immediately apparent "intuitive" answer that springs to mind effortlessly, yet this initial response consistently proves incorrect. The correct solution requires test-takers to pause, reflect carefully, and engage in deliberate analytical reasoning.
For the bat and ball problem, most people instinctively answer ten cents, but this is mathematically impossible given the parameters. The correct solution reveals the ball costs five cents, making the bat's price $1.05, exactly one dollar more, with the combined total equaling $1.10.
The widget manufacturing question typically elicits the response of one hundred minutes, but the correct answer remains five minutes. Since each individual machine produces one widget in five minutes, one hundred machines working simultaneously would manufacture one hundred widgets in that same five-minute timeframe.
The lily pad question commonly receives twenty-four days as an answer, but this fails to account for exponential growth patterns. The correct solution is forty-seven days, since the patch doubles daily, meaning coverage expands from fifty percent to one hundred percent in just one additional day.
Research Findings and Global Variations
Multiple studies conducted over the past two decades have administered the CRT to thousands of university students, consistently finding that fewer than twenty percent achieve perfect scores across all three questions. Professor Frederick's original research at the Massachusetts Institute of Technology, published in the Journal of Economic Perspectives, tested 3,428 participants primarily from MIT, Princeton, and Harvard, with only seventeen percent answering all questions correctly.
A 2011 investigation published in Memory & Cognition tested 346 college freshmen and discovered an even lower success rate of just 6.6 percent. However, cultural variations emerged in a 2016 study published in Judgment and Decision Making, where Professor Mohammad Noori reported that 41.3 percent of 395 Iranian university students correctly answered all three CRT questions.
The Social Media Debate Continues
Despite the test's scientific validation, social media platforms continue to host vigorous debates about the correct answers. One viral TikTok thread discussing the widget question generated comments like "Lmao everyone thinks it's 5 minutes" with the immediate response "It is tho." Another discussion about the bat and ball problem, viewed over 5.5 million times, included the mistaken assertion "The bat costs 1.50, the ball costs .50. You get them both for 1.10," prompting another user to respond "The math ain't mathing."
These ongoing debates demonstrate how the CRT continues to challenge our intuitive thinking processes while providing valuable insights into cognitive reflection abilities that correlate strongly with broader measures of intelligence, including standardized tests like the SATs.
