By name: three-bs-behavioral-design description: A framework for driving user behavior change by identifying specific actions, removing obstacles, and providing immediate incentives. Use this when conversion is dropping, user engagement is stalling, or when launching features that require a shift in user habits.
The Three Bs of Behavioral Design
The Three Bs is a framework for moving beyond vague goals like "engagement" to drive specific, predictable user actions. It recognizes that humans are not rational; we are driven by emotion, present bias, and social norms. By diagnosing the psychological barriers at every step of a user journey, you can design interventions that align with how people actually make decisions.
1. Define the Behavior (The First B)
The most common mistake is picking an outcome (e.g., "increase retention") rather than a behavior. You must get "uncomfortably specific" about the action you want the user to take.
- Be Specific: Instead of "log in," define exactly what happens after.
- The Peloton Rule: A specific behavior looks like: "Within 7 days of starting the app, the user completes two 10-minute workouts with two different instructors."
- The Conflict Test: If your team isn't arguing over the specificity of the behavior, it’s not specific enough.
2. Identify and Reduce Barriers (The Second B)
Identify every hurdle between the user and the target behavior.
Logistical Barriers
Physical or technical friction in the flow (e.g., number of form fields, credit card entry, wait times).
- Action: Map every single screenshot of the user journey. If it’s 50 steps, document all 50.
Cognitive Barriers
Psychological hurdles that stop a user even if the path is logistically clear.
- Uncertainty Aversion: If a user is unsure about a result, they will stall or look for other options (e.g., "Will this doctor be good?").
- Status Quo Bias: People stick to what they did yesterday. You must increase motivation to break the cycle.
- Information Aversion: Users may avoid taking an action if they are afraid of the information they might receive (e.g., health test results).
3. Amplify Benefits (The Third B)
Humans suffer from Present Bias: we prioritize our current self over our future self. You must provide a reason to act today, not a reason that pays off in six months.
- Immediate Rewards: Use "Right for Wrong"—helping people do the right thing for a "wrong" (immediate/tangential) reason.
- Example: A user works out (the right thing) because they want to see the "unicorn confetti" or keep a "streak" alive (the immediate reward), rather than for long-term heart health.
- Social Norms: Highlight that "everyone else is doing it" to decrease the cognitive load of decision-making.
- Completion Bias: Use progress bars or checkboxes to trigger the human desire to finish a started task.
The Behavioral Diagnosis Process
To apply the Three Bs, perform a "Behavioral Diagnosis" on your product:
- Map the Journey: Create a deck with 100+ screenshots of the exact flow.
- Layer Psychology: At every step, label the specific psychology at play (e.g., "Here, the user faces Choice Overload").
- Identify the "Hot State": Determine where the user is most motivated and where they are "cold" or annoyed.
- Insert Strategic Friction (Counter-intuitive): If you want someone to do less of something (like sharing misinformation), add barriers. If you want them to do more, add "motivational friction" (e.g., a quiz that highlights the benefit of the product).
Examples
Example 1: Reducing Misinformation (TikTok)
- Context: Users were sharing unverified information too quickly.
- Behavior: Decrease the "Share" action on unverified videos.
- Application: Added a "Are you sure?" popup after the share button was clicked.
- Result: This "logistical friction" forced a "cold state" reconsideration, reducing shares by 24%.
Example 2: Improving Onboarding (One Medical)
- Context: Users signed up but didn't book appointments until they were sick months later, often forgetting the app.
- Behavior: Book an appointment during the initial onboarding.
- Application:
- Reduced Choice Overload by recommending one specific doctor instead of a list.
- Reduced Logistical Friction by suggesting virtual appointments for the very next day.
- Result: Bookings increased by 20%.
Common Pitfalls
- Measuring Outcomes, Not Actions: Don't set KPIs for "Active Users." Set KPIs for the specific behavior (e.g., "Set up a recurring deposit").
- Underestimating Cognitive Load: Just because a button is big doesn't mean the user knows why they should click it. Address the "Uncertainty Aversion."
- Relying on Future Benefits: Don't tell a user they will "save for retirement." Tell them they will "complete their profile today" or "get a $10 bonus now."
- Asking Open-Ended Questions: In sign-up flows, open text fields are massive cognitive barriers. Use multiple-choice or dropdowns to keep the user in a "flow state."