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A behavior only happens when three things converge at the same moment: enough Motivation, enough Ability, and a Prompt. Miss any one of the three and the behavior does not occur, no matter how good the other two look. This is the model behind most successful habit apps, health campaigns, and onboarding flows.
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Behavior (B) happens when Motivation (M), Ability (A) and a Prompt (P) all show up together. Raising one can make up for a shortfall in another, but if any of the three is completely missing, nothing happens.
Important: high motivation with a great prompt still fails if the task is too hard. A simple task with a perfect prompt still fails if nobody wants to do it. All three bars have to be up together, even briefly.
The model is most useful whenever you want someone (including yourself) to do something repeatedly, and the obvious fix, "just remind them more" or "just motivate them more," hasn't worked.
Developed by behavior scientist BJ Fogg at Stanford's Behavior Design Lab. Unlike a sequence of steps, these three elements have to be present together, not completed one after another.
How much someone wants (or doesn't want) to do it right now. Driven by three core pulls: sensation (pleasure vs. pain), anticipation (hope vs. fear), and belonging (acceptance vs. rejection).
How easy the behavior is to do right now. Shaped by time, money, physical effort, mental effort, how socially acceptable it feels, and how routine it already is.
The thing that triggers the behavior at that moment. Comes in three forms: a spark (boosts motivation), a facilitator (makes an easy task even easier), or a signal (a plain reminder once both are already high).
Fogg's "action line" on a Motivation–Ability graph: above it, a well-timed prompt triggers the behavior. Below it, the same prompt gets ignored, however well designed it is.
Open a use case to see what the model changes.
Ask which of the three is missing at the moment they'd need to return. Usually it's not motivation, it's that the return path isn't easy or there's no prompt bringing them back at the right moment.
Shrink the behavior until Ability is almost trivially high (one push-up, one sentence of journaling), then attach it to an existing routine as the Prompt, rather than relying on willpower (Motivation) alone.
Check whether the plan assumes more time, money, or physical capability than the patient actually has. A technically "simple" instruction can have very low real-world Ability for a specific patient.
Agreement is Motivation. Action also needs Ability (a frictionless next step) and a Prompt delivered at a moment the person can actually act, not just when it's convenient to send.
Training raises awareness, not necessarily Motivation or Ability. Look for whether the new process is genuinely harder than the old habit, and whether anything actually prompts people at the point of work.
Knowing what to do is not the same as being prompted to do it at the right moment with low enough effort. Attach the technique to an existing routine rather than asking for a new standalone habit.
This is an illustrative example designed to teach the method; the numbers are for demonstration only.
Expand for the model's origin, its boundaries, and an honest look at its criticisms.
BJ Fogg, a behavioral scientist at Stanford University, developed the model and founded Stanford's Behavior Design Lab. His early research (through the 2000s) focused on persuasive technology; around 2009 he shifted his focus toward everyday human behavior and habits, which led to B=MAP and later his book Tiny Habits. Fogg's own materials describe the model as being referenced in well over a thousand academic publications.
Motivation draws on three core pulls: sensation (seeking pleasure or avoiding pain), anticipation (hoping for a good outcome or fearing a bad one), and belonging (wanting acceptance or fearing rejection). Ability depends on six "simplicity factors": time, money, physical effort, mental effort, whether the behavior fits existing routines, and whether it feels socially acceptable. Any one of these six, if scarce enough, can single-handedly make a behavior too hard.
The model is deliberately simple, and that is both its strength and its limitation. Critics note it can understate unconscious influences, social context, and structural barriers that no amount of prompt-redesign will fix. The same mechanics that make a habit app more effective can also be used to build manipulative "dark patterns," such as urgency countdowns or guilt-based prompts that push people toward a choice that serves the business rather than the person. Using the model well means being honest about which side of that line a design choice falls on.
Motivational messaging is the most common fix teams reach for, but it's frequently not the missing piece. Diagnose all three elements before investing in a pep talk, a discount, or a fear-based message.
More reminders aimed at a genuinely hard or tedious task just train people to ignore notifications. Lower the effort required before increasing how often you ask.
A plain reminder (signal) does nothing for someone with low motivation and low ability; they need a spark, something that genuinely raises motivation or shrinks the task, not just a nudge.
Sensation, anticipation, and belonging all fade with repetition and context. A message that worked last quarter can lose its pull even if nothing about the product changed.
Manufactured urgency, guilt, or social pressure can technically raise Motivation, but at the cost of trust. The model describes what triggers behavior; it doesn't excuse using that power against someone's own interests.
Motivation, Ability, and Prompt aren't three sequential steps; they have to be true at the same moment. Satisfying them one at a time, days apart, does not add up to a triggered behavior.
the real obstacle is manipulative by design. If the honest goal is to pressure someone into something against their own interest, this is the wrong tool to reach for, full stop.
motivation and ability are both genuinely low for structural reasons (cost, access, policy) that no amount of clever prompting or micro-habit design can fix.
you're facing a single, complex, one-time decision rather than a repeatable behavior. Models like Pre-Mortem Analysis or Second-Order Thinking fit a one-off choice better than a trigger-based model built for habits.
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Save the skills you find useful and organize them into your own reusable library. The Markdown is intentionally model-neutral, so it can be used wherever an AI system accepts uploaded files, project knowledge, custom instructions or reusable text context. Platform capabilities differ, so this is a portable skill file rather than a claim of one-click installation.
No. They need to be true at the same moment, not completed in sequence. You can raise Ability first, add a Prompt second, and Motivation can already have been present the whole time; what matters is that all three are true together when the moment arrives.
A spark is used when Ability is already high but Motivation is low; it tries to create motivation in the moment (for example, showing a friend's progress). A facilitator is used when Motivation is already high but Ability is low; it makes the task easier right then (a pre-filled form). A signal is just a plain reminder, appropriate only when both Motivation and Ability are already high and the person simply needs a nudge, such as a calendar alert for a meeting you already want to attend and know how to join.
They're related but distinct. The Fogg Behavior Model explains the conditions required for any single behavior to occur. The Hook Model (trigger, action, variable reward, investment) is a product-design cycle built to create repeat engagement over time, and it leans heavily on Fogg's underlying mechanics, especially Prompt (trigger) and Ability (easy action), while adding reward and investment as its own habit-forming loop.