mental-model-applier

name

mental-model-applier

description

Use when stuck on any problem or decision and need frameworks that actually apply to the specific situation — not a generic list. Selects the three most relevant mental models for the problem at hand and applies each one to produce a specific insight. Triggers: "apply mental models", "I'm stuck on", "need a framework for", "different perspective on", "mental model", "thinking framework", "perspective shift", "been thinking about this too long".

Iron Law

NO GENERIC MODEL LISTS — select models based on fit to this specific problem; applying the wrong model confidently produces worse outcomes than no model at all

Mental Model Applier

Mental models are only useful when applied, not listed. The problem is not that people lack mental models — it is that they apply the same 2-3 familiar ones regardless of whether they fit. This skill selects the three models with the highest fit to the specific problem and applies each one to produce an insight the user was not seeing.

When to Use This Skill

• You have been thinking about a problem from the same angle for too long
• A decision keeps feeling difficult despite having information
• You want a perspective shift, not more research
• You need to explain or reframe a situation to someone else
• You are about to act from habit rather than considered judgment

Core Workflow

1. Understand the problem — Read the situation carefully. Identify: Is this a decision, a diagnosis, a design problem, a people problem, or a strategy problem? The problem type constrains which models are relevant.
2. Select three models — Choose from the model library (see references/model-library.md) based on fit to the specific situation. Do not default to popular models. Choose models that illuminate this problem.
3. Apply each model — Apply it specifically to the situation. "This model suggests you think about incentives" is not an application. Name the specific incentives, the specific constraints, the specific dynamic.
4. Extract the dominant insight — Synthesize across all three models. What does the combination reveal that no single model showed?
5. State the action — One concrete thing to do differently based on the analysis.

Output Format

## Mental Model Analysis: [Problem / Decision]

### Model 1: [Model Name]
**What it says:** [One sentence — the core claim of this model]
**Applied here:** [How this model specifically maps to this situation. Specific, not general.]
**Insight produced:** [What this model reveals that was not visible before]

### Model 2: [Model Name]
**What it says:** [One sentence — the core claim of this model]
**Applied here:** [How this model specifically maps to this situation. Specific, not general.]
**Insight produced:** [What this model reveals that was not visible before]

### Model 3: [Model Name]
**What it says:** [One sentence — the core claim of this model]
**Applied here:** [How this model specifically maps to this situation. Specific, not general.]
**Insight produced:** [What this model reveals that was not visible before]

### The Dominant Insight
[One sentence. What emerges from the combination of all three models — not a repeat of any single model's insight.]

### The Action
[One sentence. What to do differently based on this analysis.]

Model Selection Criteria

Choose models based on fit, not fame. Match the model to the problem type:

Problem Type	Likely Useful Models
Decision under uncertainty	Expected value, Regret minimization, Reversibility
People / incentives	Principal-agent, Goodhart's Law, Game theory
Systems / feedback	Second-order thinking, Feedback loops, Unintended consequences
Strategy / competition	Competitive moats, Prisoner's dilemma, OODA loop
Diagnosis / root cause	Five Whys, Inversion, First principles
Design / complexity	Occam's Razor, Forcing function, Abstraction layers
Bias / judgment	Availability heuristic, Sunk cost, Overfitting

When two models would produce the same insight, replace one with a model from a different domain — cross-domain application surfaces more.

Rules

• The application section must name specific elements of the user's situation, not generic advice.
• The three models must come from at least two different domains (e.g. not three psychology models for a strategy problem).
• The dominant insight must emerge from the combination — if it is just a repeat of one model, the synthesis failed.
• The action must be concrete enough that the user knows what to do next session, not just in principle.
• If the problem is underspecified, ask one clarifying question before selecting models. Do not apply models to a vague statement.

Common Failure Modes to Avoid

Failure	What to Do Instead
Applying the three most famous models (first principles, Occam's Razor, inversion) regardless of fit	Match model to problem type using the selection criteria above
Describing a model without applying it ("Inversion says to think backwards…")	Apply it: "Inverting this: instead of asking how to grow users, ask what would cause us to lose every user we have, then eliminate those causes")
Dominant insight that repeats one model's output	Synthesize — the dominant insight must require all three models to produce
Action that is vague ("think more carefully about incentives")	Action must be specific ("restructure the contractor payment to be output-based, not time-based")

Deep Reference

Load references/model-library.md when you need the full model catalog with definitions, use cases, and application patterns.

Related

For adversarially stress-testing a conclusion after applying models: use the-fool skill. For mapping downstream consequences of an action: use second-order-thinker skill. For validating a design decision with structured peer review: use multi-agent-brainstorming skill.