The behavioral science of default options
The iPad tip screen is not neutral. It is choice architecture — a
term coined by behavioral economists Richard Thaler and Cass Sunstein
at the University of Chicago in their landmark 2008 book Nudge.
The way options are presented systematically influences which option
people choose.
Default options are particularly powerful. In a famous 2003 study published
in Transplantation, Columbia University researchers Eric Johnson
and Daniel Goldstein found that organ donation consent rates ranged from
4% to 86% across European countries — the primary
difference being whether the form defaulted to “opt-in” or “opt-out.”
Defaults shape behavior far more than conscious preference.
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For reasons of laziness, fear, and distraction, many people will take whatever option requires the least effort. If defaults are set wisely, people's lives will be improved.
Richard Thaler & Cass Sunstein, Nudge (2008)
When Square, Toast, and Clover present 18%, 20%, 25% as the visible
options — with “Custom” and “No Tip” requiring extra taps — they are not
merely providing choice. They are anchoring expectations.
The middle option (often 20%) becomes the path of least resistance.
This is the same anxiety mechanism
that makes the check moment uncomfortable at sit-down restaurants — amplified
by a public screen and a ticking clock.
Why 25% appears at all: Anchoring research by Thaler, Sunstein,
and Balz (2013) in The Behavioral Foundations of Public Policy shows
that people evaluate options relative to the highest number visible. When 25%
appears on screen, 20% feels moderate by comparison. Remove the 25%
option and suddenly 20% feels aggressive.
Sources: Johnson & Goldstein, “Defaults and Donation Decisions,”
Transplantation (2003); Thaler & Sunstein, Nudge,
Yale University Press (2008)
