Fogg Behavior Model (B = MAT)
CanonicalConfidence
Cognitive Load
Medium
Evidence
production validated
Impact
feature
Ethical Guardrail
Agents must never exploit low-ability users by pushing high-motivation prompts that create guilt or anxiety.
Design Intent
Behavior does not happen by accident. It only occurs when three specific elements come together at the exact same moment. The Fogg Behavior Model (B = MAT) is the simplest and most practical diagnostic tool in behavioral design. It states that Behavior (B) = Motivation (M) + Ability (A) + Trigger (T). If any one of the three is missing or too weak, the behavior will not occur. Designers and AI agents do not need complex psychology. They need a clear 3-part lens to instantly diagnose why users drop off and then intervene with precision instead of guesswork. When used correctly, B = MAT turns vague 'users aren't engaging' complaints into exact, fixable problems.
Psychology Principle
Behavior (B) happens only when Motivation (M), Ability (A), and a Trigger (T) converge at the exact same moment.
Description
BJ Fogg's simplest and most practical diagnostic tool: if a behavior isn't happening, one of the three elements is missing or too weak.
When to use
Any time you need a user to perform an action -- onboarding, habit features, checkout, AI suggestions, etc.
Example
Duolingo daily lesson: high motivation (streaks), tiny ability (30-second lesson), perfectly timed push notification.
Autonomy Compatibility
Behavioral Objective
Users consistently perform the target action when the opportunity arises.
- Users feel the action is easy
- Users respond to prompts positively
- Reduced reliance on willpower
Target Actor
role
Everyday user
environment
Distracted, multitasking, attention-scarce
emotional baseline
Variable motivation, cognitive fatigue
ai familiarity
medium
risk tolerance
medium
Execution Model
ability
User must be able to perform the action with almost no effort.
User starts the action but abandons midway because it feels hard.
motivation
User must want to perform the action right now.
User sees the prompt but feels 'I don't care right now.'
trigger
User must be prompted at the exact moment when motivation and ability are high.
User never sees the prompt or sees it at the wrong time.
Failure Modes
High motivation but zero ability creates guilt
Simplify the action first using Action Structuring
Strong trigger with low motivation leads to prompt fatigue
Strengthen motivation before increasing trigger frequency
Over-reliance on motivation causes burnout
Anchor to Tiny Habits and existing routines
Weak or poorly timed triggers cause missed opportunities
Use Contextual Triggers tied to user routines
All three elements present but behavior still fails
Diagnose hidden environmental blockers
Agent Decision Protocol
Triggers
- User ignores repeated prompts
- Action completion rate suddenly drops
- Users report 'I keep meaning to do this but never do'
Escalation Strategy
L1: Diagnose which of the three B=MAT elements is weakest via behavioral_signals
L2: Nudge -- adjust trigger timing, add motivation cue, or simplify action
L3: Restructure -- apply Tiny Habits or Action Structuring to reduce ability gap
L4: Constrain -- limit prompt frequency to prevent fatigue, lock to high-ability moments
L5: Yield -- flag for human behavioral designer review
Example
User opens Duolingo notification but closes it -> Ability failure -> retrieve Action Structuring -> propose 15-second micro-lesson instead of full exercise.
Behavioral KPIs
Primary
- Action completion rate when prompted
- Median time from trigger to completion
- Prompt dismissal rate
Risk
- User-reported frustration after failed attempts
- Drop-off in habit-forming features
Trust
- Positive sentiment toward prompts
- Autonomy Dial usage when agent suggests actions
Behavioral Signals
motivation_failure
prompt_viewed=true AND action_started=false AND dwell_time < 3s
prompt_dismissed=true AND repeat_dismiss_count > 2
ability_failure
action_started=true AND action_completed=false AND time_in_action > 60s
action_abandoned_midway=true
trigger_failure
prompt_delivered=true AND prompt_viewed=false
time_since_last_action > 48h AND prompt_sent=false
Decay Monitoring
Revalidate when
- New user segments with different motivation baselines onboard
- Platform notification policies change
- Product introduces major new features that alter ability
Decay signals
- Rising prompt dismissal rates
- Increased user complaints about spam or guilt trips
- Drop in long-term retention despite short-term engagement spikes
Pattern Relationships
Supports
Amplifies
Requires
Conflicts with