Published: February 2002
Mental Models: Reciprocity
Circulated: October 29, 2020
People tend to return a favor. When you offer something first for free, people feel a sense of indebtedness towards you. That’s why when a friend invites you to their party; there’s an obligation for you to invite them to a future party you are hosting.
Example: the use of candy to increase restaurant tipping
Researchers found that most people will feel they owe a debt when given a mint for free and will repay it by leaving a higher tip.
When a waiter leaves one after-dinner mint when they drop off your check, you will tip 3% more than if no mint was given. But when the waiter leaves two mints, your tipping increases to 14% more than no mint! To receive a 23% greater tip than no mint, a waiter can drop off one mint, leave, and then come back to your table with a second mint.