hooked-ux

# Hook Model Framework

Framework for building habit-forming products. Habits are not created — they are built through successive cycles through the Hook.

## Core Principle

**The Hook Model** = a four-phase loop that connects the user's problem to your solution frequently enough to form a habit, moving usage from deliberate to automatic.

```
Trigger → Action → Variable Reward → Investment
    ↑                                      │
    └──────────────────────────────────────┘
```

## Scoring

**Goal: 10/10.** When reviewing or creating product engagement mechanics, score the loop by the four Quick Diagnostic rows (internal trigger, dead-simple action, variable reward, investment loads next trigger): each row earns 2 (fully satisfied), 1 (partial), or 0 (absent), then `score = round(total / 8 × 10)`. Then apply the ethics gate: if the Manipulation Matrix places the product as Dealer (or it hits any "When NOT to Use" condition), cap the score at 3 regardless of mechanics. Bands: 9-10 = complete loop, internal trigger identified, ethics clear; 5-6 = loop runs but leans on external triggers or predictable rewards; <=3 = broken loop or extractive design. Always state the current score and the specific diagnostic rows blocking 10/10.

## The Four Phases

### 1. Trigger

**Core concept:** The actuator of behavior. Triggers are external (environment-driven: notifications, emails, ads) or internal (emotion-driven) — and the goal is to migrate users from external to internal triggers.

**Why it works:** Every habit starts with a cue. External triggers get users started, but internal triggers — boredom, loneliness, uncertainty, FOMO — drive unprompted usage because the emotion itself fires before any reminder can.

**Key insights:**
- Map your product to the specific negative emotion it resolves (boredom, loneliness, confusion, FOMO)
- Effective external triggers are well-timed, actionable, and lead to the simplest possible next action
- If users still need external prompts after ~30 days, no internal trigger has formed

**Product applications:**

| Context | Application | Example |
|---------|-------------|---------|
| **Onboarding** | External triggers establish the first loop | Welcome email with one clear action |
| **Retention** | Map product to internal emotional trigger | Instagram resolves boredom; Google resolves confusion |
| **Re-engagement** | External triggers bridge gaps until habit forms | Push: "Your friend just posted a photo" |

**Copy patterns:**
- "Don't miss what happened while you were away" (FOMO trigger)
- "Your friend just..." (social trigger bridging to internal)
- "Pick up where you left off" (routine trigger)

**Ethical boundary:** Don't build triggers that fire on vulnerable emotional states (depression, addiction, grief) — those users can't exercise the autonomy the loop assumes.

See [references/triggers.md](references/triggers.md) when mapping triggers — the emotion-to-product mapping exercise and the external-to-internal transition plan.

### 2. Action

**Core concept:** The simplest behavior done in anticipation of a reward, guided by the Fogg Behavior Model: Behavior = Motivation + Ability + Trigger, all converging at the same moment.

**Why it works:** Increasing motivation is hard and unreliable; reducing friction (increasing ability) is easier and more effective. Every extra step, field, or decision is a drop-off point.

**Key insights:**
- Six elements of simplicity: time, money, physical effort, brain cycles, social deviance, non-routine
- The action is the simplest behavior in anticipation of reward — not the full task
- Hick's Law: more choices = slower decisions; reduce options to increase action rate

**Product applications:**

| Context | Application | Example |
|---------|-------------|---------|
| **Signup flow** | Minimize fields and steps | One-click Google/Apple sign-in |
| **Core action** | Completable in seconds | Twitter: type 280 characters and post |
| **Progressive disclosure** | Ask for more only after initial reward | Duolingo: play first, create account later |

**Copy patterns:**
- "Just one tap to..." (emphasizes simplicity)
- "No credit card required" (money/risk simplicity)
- Buttons should be verbs: "Post", "Save", "Share" — not "Submit" or "Continue"

**Ethical boundary:** When you simplify an action, don't strip the cost or consequence with it — a one-tap purchase must still surface the price and the commitment.

See [references/product-applications.md](references/product-applications.md) when adapting the loop to your context — action and investment patterns for B2B SaaS, e-commerce, health, and productivity tools.

### 3. Variable Reward

**Core concept:** The phase that keeps users coming back. Anticipation of reward — not the reward itself — creates dopamine, and rewards must be variable (unpredictable) to sustain engagement.

**Why it works:** The brain's dopamine system responds most strongly to anticipation of uncertain rewards — the slot machine effect. Three reward types — tribe (social), hunt (resources), self (mastery) — tap fundamental human drives.

**Key insights:**
- Tribe = social validation; Hunt = search for resources/information; Self = personal mastery
- Predictable rewards lose power; finite variability eventually becomes predictable — aim for infinite variability
- Autonomy is critical: users must feel in control; forced engagement backfires

**Product applications:**

| Context | Application | Example |
|---------|-------------|---------|
| **Social features (Tribe)** | Variable social validation | Instagram likes — you never know how many |
| **Content feeds (Hunt)** | Unpredictable resource stream | Infinite scroll with algorithmically varied content |
| **Gamification (Self)** | Accomplishment with variable difficulty | Duolingo streaks + surprise bonus challenges |

**Copy patterns:**
- "See what's new" (implies variability)
- "3 people responded to your post" (tribe reward, variable quantity)
- "You'v