7.2.3. In Real Life
You can see charities using this anchoring and adjustment hack when they send you their literature. Take a look at the “make a donation” section on the back of a typical leaflet. Usually this will ask you for something like “$50, $20, $10, $5, or an amount of your choice.” The reason they suggest $50, $20, $10, then $5 rather than $5, $10, $20, then $50 is to create a higher anchor in your mind. Maybe there isn’t ever much chance you’ll give $50, but the “amount of your choice” will be higher because $50 is the first number they suggest.
Maybe anchoring explains why it is common to price things at a cent below a round number, such as at $9.99. Although it is only 1 cent different from $10, it feels (if you don’t think about it much) closer to $9 because that’s the anchor first established in your mind by the price tag.
Irrelevant anchoring and insufficient adjustment are just two examples of difficulties we have when thinking about numbers. ( [Hack #71] discusses extra difficulties we have when thinking about a particularly common kind of number: probabilities.)
The difficulty we have with numbers is one of the reasons people so often try to con you with them. I’m pretty sure in many debates many of us just listen to the numbers without thinking about them. Because numbers are hard, they lend an air of authority to an argument and can often be completely misleading or contradictory. For instance, “83% of statistics are completely fictitious” is a sentence that could sound convincing if you weren’t paying attentionso watch out! It shows just how unintuitive this kind of reasoning is, that we still experience such biases despite most of us having done a decade or so of math classes, which have, as a major goal, to teach us to think carefully about numbers.
The lesson for communicating is that you shouldn’t use numbers unless you have to. If you have to, then provide good illustrations, but beware that people’s first response will be to judge by appearance rather than by the numbers. Most people won’t have an automatic response to really think about the figures you give unless they are motivated, either by themselves or by you and the discussion you give of the figures.
7.2.4. End Notes
The MacTutor History of Mathematics Archive: a History of Zero (http://www-gap.dcs.st-and.ac.uk/~history/HistTopics/Zero.html).
Russo, J. E., and Schoemaker, P. J. H. (1989). Decision Traps. New York: Doubleday.
Taken from : Mind Hacks
