The Fogg Behavior Model: B = MAP
A behaviour happens when Motivation, Ability and a Prompt meet at the same moment. Move the sliders and watch when a prompt succeeds.
The behaviour happens.
Best prompt type here: Signal: a plain reminder is enough.
What the chart teaches
Try the “New year gym plan” scenario: motivation is sky-high but ability is low, so the dot sits near the line and slips below it as soon as motivation fades. Now try “Floss one tooth”: very little motivation needed, because it’s so easy. That asymmetry is the core of Fogg’s advice: motivation is unreliable, so design for ability.
The three ingredients
- Motivation fluctuates with sensation, anticipation and social belonging. It’s the hardest to control and the least dependable.
- Ability is limited by the scarcest of time, money, physical effort, mental effort and fit with routine. Shrinking the behaviour raises ability, which is the logic behind Tiny Habits and the 2-Minute Rule.
- Prompt is the “do it now” trigger. Without one, nothing happens however motivated you are. The most dependable prompt is an existing routine: an anchor.
Using B=MAP when a habit fails
Fogg suggests troubleshooting in order: first check the prompt (was there one?), then ability (can it be made easier?), and only then motivation.
Sources: Fogg, B. J. (2009). A behavior model for persuasive design. Proceedings of Persuasive ’09. Fogg, B. J. (2019). Tiny Habits. The curve above is illustrative, not a fitted model.
Keep designing
- Habit trackerDesign habits with a cue, identity and 2-minute start, then stitch off each day.
- Habit stackingAnchor a new habit to one you already do.
- 2-Minute RuleShrink any habit until starting is easy.
- Tiny Habits recipeBJ Fogg’s anchor, behaviour, celebration.
- If-then plannerDecide when and where in advance.
- Temptation bundlingPair a “should” with a “want”.
- Habit scorecardAudit what you already do each day.
- Break a bad habitInvert the four laws into a plan.
- Morning routine builderA timed stack for the first hour.
Questions
What is the Fogg Behavior Model?
Developed by BJ Fogg at Stanford, the model states that a behaviour happens when three elements converge at the same moment: Motivation, Ability and a Prompt, written B = MAP. If a behaviour doesn’t happen, at least one of the three is missing.
What is the action line?
On Fogg’s chart, motivation is on the vertical axis and ability on the horizontal. The action line is a curve: above it, a prompt leads to the behaviour; below it, the prompt fails. The easier a behaviour is, the less motivation it needs to get above the line.
What are the three types of prompts?
Fogg describes a Facilitator prompt (for high motivation but low ability: make it easier), a Spark (for high ability but low motivation: add motivation) and a Signal (when both are high: just a reminder).
What makes something easier to do?
Fogg lists ability factors such as time, money, physical effort, mental effort and routine. A behaviour is only as easy as its scarcest factor, which is why shrinking the behaviour usually works better than trying to raise motivation.