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Cognitive biasEstablished researchFoundational

Default Effect

Most people accept whatever is preselected, which makes defaults the most powerful control in an interface.

Definition

The tendency to stay with a preselected option. Johnson and Goldstein's 2003 analysis of organ donation rates across European countries found dramatically different participation between opt-in and opt-out defaults, with otherwise similar populations.

Established research. Originates in published research and has been replicated. The effect is real. Its size in your product still needs measuring.

On this page
  1. Definition
  2. Defaults are decisions you make for people
  3. Choosing a good default
  4. In practice
  5. Sources
  6. Continue from here

Defaults are decisions you make for people

Every preselected value, every toggle position and every sort order is a decision the product makes on the user's behalf, and most users will accept it. Treating defaults as an afterthought means shipping a large number of unexamined decisions.

The design obligation is to choose the default that is best for the user in the common case, and to make changing it easy and visible.

Choosing a good default

  1. 1.Identify the most common case with data, not intuition.
  2. 2.Prefer the safest option where the cases are close, particularly for anything involving privacy, money or data sharing.
  3. 3.Make the default visible rather than implicit, so acceptance is informed.
  4. 4.Make changing it a single obvious action.
  5. 5.Remember the change, so a user who chose differently is not asked again.

In practice

Privacy defaults

Social products

Defaulting new accounts to the most private setting and letting users open up deliberately is the choice that respects the effect rather than exploiting it.

Sensible sort orders

Lists and tables

Most users never change the sort. Choosing the order that answers the most common question, rather than the one that is easiest to implement, is a meaningful design decision.

Sources

Where a source establishes something narrower than the popular reading of it, the note says so.

  • Do defaults save lives?

    E. J. Johnson and D. Goldstein, Science, 2003

  • General Data Protection Regulation, Article 4(11) and Recital 32

    European Union, 2016

    Establishes that consent requires a clear affirmative act, ruling out pre-ticked boxes.

Continue from here

Each link says what the connection is, so you can tell a principle from an alternative from a thing people mix this up with.

Applies when you are designing

Settings

Explains

The mechanism underneath these entries.

Applied through

Where this shows up as a concrete interface decision.

Practical example

A worked decision where this was the deciding factor.

Check your work

Review passes that test whether this was done properly.

Short definition

The one-paragraph version, for when that is all you need.

Related concept

Connected closely enough to change how you apply this.