Belief: Anchoring

Try this:

Add 400 to the last three digits of your cell phone number. When you are done, answer the following question: in what year did Attila the Hun’s rampage through Europe finally come to an end?

This is a lovely example of the Anchoring Effect. When our attention is directed somewhere – in this case to the sum of 400 and the last three digits of our cell phone number – we use that as a starting point, an anchor, from which to search for an answer. We move from the anchor and stop when we get to a plausible answer.

The correct answer to the question is 451 CE. However, the average guess for people whose sum was less than 600 was 629 CE, while the average guess for people whose sum was between 1200 and 1399 was 979 CE. Starting with a different anchor led to a difference of 350 years in their guesses.

So be aware, very aware. As Gary Marcus says in the footnote on page 47 of Kluge,

If you’re aware of the process of anchoring and adjustment, you can see why during a financial negotiation it’s generally better to make the opening bid than to respond to it. This phenomenon also explaisn why, as one recent study showed, supermarkets can sell more cans of soup with signs that say LIMIT 12 PER CUSTOMER rather than LIMIT 4 PER CUSTOMER.