Framework · Behavioral science · Hooked
Fogg Behavior Model (B = MAP)
A behavior happens when motivation, ability and a prompt meet at the same moment; when it fails, at least one is missing. Hooked calls the prompt a trigger (B = MAT). Use it to triage a drop-off step, working ability first. Evidence for the model as a whole is limited (grade C).
Plain label: motivation, ability and prompt modelAlso known as: B=MAT, B=MAP, Tiny Habits, Fogg model, behavior triage
Core idea. Motivation rises and falls, so durable designs make the behavior easier and put a prompt where the person already is. Ability is set by the scarcest of six simplicity factors for that person at that moment: time, money, physical effort, brain cycles, social deviance and non-routine. F01 (A behavior model for persuasive design, Fogg, Persuasive 2009 (ACM), 2009)
How it plugs in. Behavior triage of a drop step asks which ingredient was missing: a prompt that reached the user when they could act, the ability to act right then, or the motivation to want to. Work in Hooked's order: ability first, then motivation, then heuristics. HK-T06 (Hooked Ch.3)
Evidence. Evidence grade C. Limited evidence: few or small studies. The model is widely cited, but the full model, including its "action line", has not been validated as a predictive theory, and direct tests are small. Its parts lean on stronger literatures: friction and defaults (B), context-cue repetition (A), if-then planning (A-/B+). Celebration as habit glue is the least tested element.
Watch-outs. Never put a number on the action line. Prompts that fire when ability is low teach users to ignore prompts.
Limits
What we don’t claim
- The Hook Model is a practical design tool, not a validated or complete theory of behavior.Hooked, Introduction
Sources
Hooked · Nir Eyal
Ch.3
A behavior model for persuasive design · B.J. Fogg, Persuasive 2009 (ACM), 2009
Evidence grade C. Limited evidence: few or small studies.A behavior model for persuasive design · Fogg, Persuasive 2009 (ACM), 2009
Evidence grade C. Limited evidence: few or small studies.
Book content is paraphrased, never quoted at length. Last verified October 24, 2026.
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