Confidence is easy to feel and hard to check. That tension sits at the center of Misbelief, the 2023 book by behavioral economist Dan Ariely, and it returns in an October 16 blog post that adapts a section of the book for a short, practical exercise: draw a bicycle, then ask what else you only think you understand.
From Bicycles to Beliefs
Ariely opens with a number. People typically rate their understanding of a bicycle at eight or nine out of ten. Asked to draw one, they often discover gaps. In a 2006 study by Rebecca Lawson of the University of Liverpool, participants given a partial drawing and asked to add the frame, pedals and chain rarely produced a working machine, and their average self-rating fell by nearly half afterward.
Yale researchers Leonid Rozenblit and Frank Keil found a broader version of the same effect when they asked people to explain everyday items such as zippers, helicopters and flush toilets, as well as presidential elections. Confidence dropped sharply once participants tried to explain step by step, and it stayed down even after they read expert accounts. They called it the illusion of explanatory depth.
The Dan Ariely Version of the Test
Ariely’s twist is to point the test at belief instead of machinery. He asks readers to choose a position they hold strongly that other people do not share, then try to explain it the way they would explain how a bicycle works. As the post presents it, the aim is the same one that made the bicycle exercise work: to bring your self-assessment closer to what you actually know, by finding out how much of a belief rests on explanation and how much rests on simply feeling sure.
That is a different goal from winning an argument. It asks a person to try to supply the missing steps, a task that is hard to do while defending a position. Ariely’s post links to a belief audit tool for readers who want a structured way to run the exercise.
The approach fits a long career. Ariely, who spent years at MIT before moving on to other institutions, has carried the study of how people judge and decide into popular books ever since.
Where the Exercise Leads
Trying the audit rarely produces a dramatic reversal. More often, it produces a more modest and more useful state: knowing which parts of a belief you could defend and which you borrowed. It is also the kind of everyday self-knowledge that readers of his Scientific American byline will recognize from his work for general audiences.
The same instinct extends beyond personal beliefs to public life. Readers interested in how Ariely has applied this thinking to civic questions can find what he has written about fixing democracy summarized in a recent overview of his published work on voting and participation. That coverage is explicit that his research is not a campaign platform.
The bicycle test, in the end, is a small and inexpensive discipline. It asks for a pencil, a belief, and a willingness to discover what is missing. For many people, discovering that is the more valuable result.









