Zippers & Illusion of Knowledge

ZIPPERS ARE ALL AROUND US. On our trousers. And our bags. Hardly a day goes by without our zipping or un-zipping something. If someone asked you if you knew how zippers worked, I am guessing like most of us, you too would be quick to say, "I know".

- Prakash lyer

Two researchers at Yale - Leonid Rozenblit and Frank Keil-had an interesting idea though, some 20 years ago. They asked a group of students to rate on a scale of 1-7 how well they understood how zippers worked. As you might expect, most responses were at the upper end of the scale.

Next, they gave the students pen and paper and asked them to explain how zippers worked. (Maybe you should try doing that too right now, just so you know what happened). And then they asked the students, one more time, to rate their understanding of how zippers worked - on the same seven-point scale. Most students lowered their score by a couple of points this time around.