Behavioral Science and Behavior Design
Throughout this course you will design for Kosh, a savings app for people in their first salaried job. In a sign-up survey, eight in ten new users tick "I want to build an emergency fund". A month later, only one in ten has moved a single rupee. Nobody lied on the survey. Something between wanting and doing got in the way, and that something is what this course is about.
The rule
Behavior design closes the gap between what people intend and what they do.
Behavioral science is the study of how people actually decide and act, drawing on psychology, economics and sociology. Its central finding for designers is uncomfortable: people often do not do what they sincerely plan to do. Researchers call this the intention–action gap.
Behavior design is the practical side: using those findings, on purpose, to shape a product so the intended action becomes more likely. It has three parts:
- The intention. The user already wants something: to save, to exercise, to learn.
- The gap. Forgetting, effort, distraction, doubt, a tempting alternative.
- The bridge. A design choice that removes or shrinks one of those obstacles.
The word "intend" also sets the ethical line. Behavior design helps people do what they want. Using the same tools to push people towards something they would not choose, simply because it helps the business, is manipulation.
Behavioral science also brings a habit of mind: test, don't guess. People are poor at predicting their own behavior, so a design is a hypothesis until you measure what users actually do.
The shortcut
For any feature, ask three questions in order: What exactly should the user do? What stops them today? What change removes that obstacle? Behavior, gap, bridge.
Name the behavior
Not "save more" but something you could see happen: move money into the emergency pot on payday.
The classic mistake is to treat a gap in doing as a gap in knowing. When users don't act, teams add more explanation: a longer article on why emergency funds matter. But the users already agreed. They needed an easier path, not a better argument.
Drills
Answer fast — trust the rule.
What does behavioral science study?
80% of Kosh users say they want to save, but 10% have saved after a month. What is this called?
Which question is the ethical test for a behavior design?
Kosh adds a long article on why savings matter, but transfers do not rise. What did the team most likely get wrong?
Remember
- Behavior design closes the gap between what people intend and what they do.
- Shortcut: behavior, gap, bridge — then check that it serves the user's own goal.
- Trap: answering a doing problem with more information.