Jussi Ahola

Curious humanist

Random taps on a tabletop

If I had a penny for every time I’ve been sitting in a lecture, seminar, conference, meeting or some other social gathering listening to a speech that was completely indecipherable, that was on a level of abstraction so high that only the speaker herself was able to make out any of it, I would be a rich man. The same applies to the written word: the times that I’ve been trying to make out the meaning of just a single paragraph in an article, e-mail message, or some other document are far too many. Acronyms, abstract words, and illogic are typical symptoms of such communication.

The problem with these speeches and texts hasn’t been that the speakers and authors don’t know what they are talking about, but rather that they are plagued by the fact that they know so much. They have fallen the victims of the Curse of Knowledge.

In an ingenious study in 1990, a Stanford University doctoral student Elizabeth Newton was able to shed some light on the magnitude of the Curse of Knowledge through a game-like experimental design. Newton assigned people into two groups: the tappers and the listeners. The tappers were asked to pick out a song from a list that contained only well known songs such as Happy Birthday to You. After this, each tapper was paired with a listener and instructed to tap to the rhythm of the song on a tabletop. No humming or singing was allowed. The listener’s job was simply to guess the song that was being tapped out to her.

As you might guess, being in the role of the listener is somewhat difficult, but actually it turned out to be a lot harder than at least I would have intuitively predicted: successful guesses accounted for only about 2.5% of all the songs that were tapped out in the course of the experiment. But here’s the catch: before the listeners revealed their guesses, the tappers were asked to make a prediction on the probability that the listener would guess correctly. On average, their prediction was a whopping 50%.

When you’re tapping out a song, it is impossible not to hear the melody playing out in your head; your knowledge of the song has cast a curse on you. Unfortunately the listener does not have that same melody playing out inside her head; 97.5 percent of the time all she has are random taps against a tabletop.

An analogy to an incomprehensible public speech is pretty obvious. The speaker has a melody playing out inside her head; all the acronyms, abstractions, and illogical connections are laid out in such an obvious way in the melody that she can’t help but to assume that the listener hears their meaning too. In many cases she has known the song for years and maybe even plays some instrument in the band. She cannot un-learn the melody and imagining what it’s like to live without the knowledge of it is hard; the Curse of Knowledge has played its trick on her. The listener, however, doesn’t have the same melody playing out inside her head.

The words that she hears could just as well be random taps on a tabletop.