improve-retentionlisted

> **Provenance.** Vendored from `wondelai/skills@improve-retention` (MIT License — github.com/wondelai/skills). Adapted into great-pm 2026-05-29 with attribution. Reference deep-dives (references/*.md) live upstream. Host agent: product-strategist. # Behavior Design Framework Framework for designing products that reliably change behavior. Based on a fundamental truth: behavior is not about willpower or motivation—it is a design problem with a predictable equation. ## Core Principle **The Fogg Behavior Model** = B=MAP. Behavior happens when Motivation, Ability, and a Prompt converge at the same moment. ``` HIGH ┃ ┃ ★ Behavior happens ┃ (above the Action Line) ┃ Motivation ┃━━━━━━━━━━━━━━━━━━━━━━━ ← Action Line ┃ ┃ ✗ Behavior fails ┃ (below the Action Line) LOW ┃ ┗━━━━━━━━━━━━━━━━━━━━━━━━━ HARD EASY Ability ``` **The Action Line:** When motivation and ability are sufficient, a prompt causes the behavior. Below the line, no prompt works. The line curves: high motivation compensates for low ability, and high ability compensates for low motivation. The reliable strategy is to make behaviors easier (move right), not to pump up motivation (move up). ## Scoring **Goal: 10/10.** When reviewing or creating product behavior design, rate them 0-10 based on adherence t