Mental model cheatsheet

Charlie Munger:

“I think it is undeniably true that the human brain must work in models. The trick is to have your brain work better than the other person’s brain because it understands the most fundamental models - ones that will do most work per unit.”
“What is elementary, worldly wisdom? Well, the first rule is that you can’t really know anything if you just remember isolated facts and try and bang ‘em back. If the facts don’t hang together on a latticework of theory, you don’t have them in a usable form.”
“You’ve got to have models in your head. And you’ve got to array your experience—both vicarious and direct—on this latticework of models.”
“The models have to come from multiple disciplines—because all the wisdom of the world is not to be found in one little academic department.”
“It’s not enough to know your own expertise area well; you have to understand the fundamental principles from other areas to be successful in the world.”

In other words, your life’s experience is the data, and mental models are algorithms or heuristics that take this data in and help you take better decisions.

Other analogy can be:

Navigation: Like using a map to navigate through unfamiliar territory, mental models guide us through the complexity of life’s challenges, helping us to chart a course and adjust as necessary.

Comprehensive Mental Models & Heuristics Reference

Category	Model/Heuristic	One-Line Rule	When to Use	Example Application	Tags
Decision Speed	ICE-V Framework	Impact × Certainty × Ease × Vibe = priority	Feature prioritization, task ordering	Rate startup ideas: High impact, medium certainty, low effort, good vibe = do it	#strategy #productivity
	10-10-10 Rule	How will I feel in 10 min/months/years?	Emotional decisions, conflict resolution	Should I send this angry email? (No in 10 years)	#decision-making
	Default to Action	If reversible, bias toward doing	Low-stakes choices, experiments	Launch MVP vs perfect planning	#startup #productivity
	Energy Audit	Does this give or drain energy?	Daily scheduling, relationship choices	Meeting at 6am vs 10am for peak performance	#productivity #health
	Two-Way Door Test	Reversible = speed, irreversible = deliberate	Resource allocation, hiring	Fire fast, hire slow	#business #strategy
Truth & Knowledge	The Map is not the Territory	An abstraction of reality is not reality itself	Critical thinking, model validation	GPS says road exists but it’s closed	#philosophy #perception
	Steel Man > Straw Man	Argue against strongest opposing view	Debates, strategy sessions	Attack competitor’s best features, not worst	#critical-thinking
	Skin in the Game	Trust people with downside risk	Taking advice, choosing advisors	VCs who invest own money vs salary-only	#trust #advice
	Via Negativa	Learn more from failures than wins	Post-mortems, research	Study failed startups > successful ones	#learning #research
	Lindy Effect	Older = longer survival expected	Technology choices, investment	Unix, SQL still here after decades	#longevity #technology
	Antifragile Filter	Gets stronger from stress/volatility	System design, personal habits	Muscle growth, startup resilience	#resilience #systems
	Occam razor	The simplest explanation is usually correct	Problem solving, hypothesis testing	Debug code: check simple issues first	#science #decision-making
Human Nature	Revealed Preferences	Watch actions, ignore words	Hiring, partnerships, dating	”I value work-life balance” but works 80hrs	#psychology #behavior
	Social Proof Cascade	People follow crowds off cliffs	Marketing, trend analysis	Everyone buying crypto at peak	#psychology #social
	Incentive Gradient	Show reward, predict behavior	Team design, policy creation	Sales team paid on revenue, not profit	#psychology #systems
	Mimetic Desire	We want what others want	Product design, positioning	iPhone desirability through exclusivity	#psychology #marketing
	Status Ladder	Most conflicts are about hierarchy	Team dynamics, negotiations	Engineer vs PM friction = status battle	#psychology #social
Systems Thinking	Feedback loop	What you measure improves/games	KPI design, goal setting	Measure lines of code → bloated code	#business #biology
	Second-Order Effects	Every action has consequences of consequences	Policy decisions, feature launches	Free shipping → higher prices → customer loss	#systems #strategy
	Leverage Points	Small changes in right place = massive impact	Problem solving, optimization	Change one database query → 10x speed	#systems #optimization
	Network effects	Value grows exponentially with users	Platform strategy, viral growth	Slack becomes more valuable with team adoption	#business #startup
	Pareto Optimization (80/20 Rule)	80% outcomes from 20% inputs	Resource allocation, debugging	20% of bugs cause 80% of crashes	#business #productivity
	Entropy	Measure of disorder in a system	Understanding system degradation	Code becomes messy without maintenance	#physics #business
	Maximum entropy	State of maximum disorder	System design, risk management	System will tend toward chaos without regulation	#physics #thermodynamics
	Equilibrium	State of balance where forces are matched	Decision-making in systems	Market price where supply meets demand	#economics #business
	Bottlenecks	Constraints that limit system capacity	Process optimization	Database query limiting app performance	#business #productivity
	Scale	System’s ability to handle growth	Business planning, architecture	Can your database handle 10x users?	#business #technology
Risk & Probability	Barbell Strategy	Extreme safety + extreme risk = optimal	Portfolio allocation, career moves	90% safe investments + 10% high-risk bets	#risk #investment
	Asymmetric Bets	Limited downside, unlimited upside	Startup ideas, experiments	Angel investing, side projects	#risk #opportunity
	Expected Value	Probability × payoff = decision metric	Gambling, business decisions	1% chance of $1M vs 50% chance of$ 1K	#probability #decision-making
	Kelly Criterion	Bet size = edge ÷ odds	Position sizing, resource allocation	How much to invest in proven strategy	#investment #risk
	Black Swan Awareness	Rare events dominate everything	Risk management, scenario planning	COVID impact on business models	#risk #planning
	Sunk cost fallacy	Don’t continue based on past investment	Decision-making, relationships	Don’t finish bad movie because you paid	#relationships #business #startup
	Law of Diminishing Returns	Incremental benefits decrease with more resources	Resource optimization	Adding more developers doesn’t always help	#economics #business
	Butterfly Effect	Small changes lead to large outcomes	Planning, risk assessment	One bug can crash entire system	#business #relationships
	Margin of Safety	Buffer between actual and minimum value	Investment, planning	Buy stock at 50% of intrinsic value	#business #finance
Communication	Pyramid Principle	Conclusion first, then evidence	Presentations, emails, reports	”We should pivot because…” then data	#communication #business
	Show Don’t Tell	Demonstration > explanation	Product demos, teaching	Live coding vs PowerPoint about code	#communication #teaching
	Mental Model Sharing	”Here’s how I think about this”	Collaboration, mentoring	Share decision framework before conclusion	#communication #leadership
	Cringe Test	Uncomfortable to say = probably true	Difficult conversations, feedback	”Your code quality is declining”	#communication #truth
	Compression Test	Can’t explain simply = don’t understand	Learning validation, teaching	Explain AI to grandmother	#communication #learning
Building & Creating	Minimum Viable Everything	Ship smallest thing that teaches	Product development, content	Blog post before book, prototype before product	#startup #product
	Compound interest	Small consistent > big sporadic	Skill building, relationship building	Daily writing vs weekend binges	#finance #investment
	Optionality Creation	Build multiple paths to success	Career strategy, product roadmap	Full-stack skills open more doors	#strategy #career
	Adjacent Possible	Next breakthrough = one step away	Innovation, research direction	iPhone = iPod + phone + internet	#innovation #research
	Emergence Over Planning	Complex systems guided, not designed	Team management, product evolution	Culture emerges from actions, not mission statements	#systems #management
	First Principles	Break to fundamental truths, rebuild	Problem solving, innovation	SpaceX rocket cost from materials up	#innovation #business #education
	Critical Mass	Minimum needed for self-sustaining process	Business growth, network building	Product needs X users to be valuable	#business #networks
	Activation energy	Energy required to initiate process	Goal setting, habit formation	Making gym clothes visible reduces startup friction	#business #productivity
Personal OS	Energy > Time Management	Protect peak hours	Daily scheduling, deep work	Code during morning energy, meetings after lunch	#productivity #health
	Keystone Habits	One habit triggers others	Behavior change, productivity	Exercise → better sleep → better focus	#productivity #health
	Identity-Based Change	”I am someone who…” vs “I want to…”	Goal setting, habit formation	”I’m a runner” vs “I want to run”	#psychology #habits
	Progress Measurement	What gets tracked gets optimized	Personal development, fitness	Daily code commits, weekly reflection	#productivity #measurement
	Environmental Design	Change context to change behavior	Productivity, health	Phone in other room for focus	#productivity #environment
Market & Competition	Competitive Moats	What makes you un-copyable?	Strategy, positioning	Network effects, switching costs	#business #strategy
	Blue Ocean Strategy	Create new markets vs fight existing	Product strategy, positioning	Create “AI agents” category vs “RPA”	#business #innovation
	Jobs-to-be-Done	People hire products for specific jobs	Product development, marketing	Hire milkshake for breakfast entertainment	#business #product
	Platform Dynamics	Connect producers + consumers = winner-take-all	Business model, growth strategy	App stores, marketplaces	#business #platforms
	Timing Beats Everything	Right idea at wrong time = failure	Market entry, feature launches	Social video before mobile bandwidth	#business #timing
	Churn	Rate customers leave product/service	Customer retention analysis	Monthly subscription cancellation rate	#business #metrics
	Counter-Positioning	New model incumbent can’t copy without damage	Competitive strategy	Netflix vs Blockbuster business models	#business #strategy
	Switching Costs	Value loss from changing suppliers	Customer retention strategy	Apple ecosystem lock-in	#business #marketing
	Branding	Higher value from reputation/history	Marketing, positioning	Premium pricing for known brands	#business #marketing
	Cornered Resource	Preferential access to coveted assets	Strategic planning	Exclusive supplier relationships	#business #strategy
	Process Power	Embedded organization enabling advantages	Operations optimization	Toyota Production System	#business #operations
Meta-Learning	Inversion	Solve by considering opposite/failure	Problem solving, risk management	How to guarantee startup failure?	#thinking #strategy
	Analogical Reasoning	Pattern match across domains	Learning, creativity	Immune system → cybersecurity patterns	#learning #creativity
	Falsification Bias	Seek evidence that proves you wrong	Hypothesis testing, decision validation	Try to disprove your startup idea	#science #thinking
	Mental Model Accumulation	Collect decision tools like apps	Continuous learning, better judgment	Regular model practice and application	#learning #improvement
	Isomorphism	Similar structures in different areas	Pattern recognition, problem solving	Social networks and neural networks	#education #research
	Heisenberg uncertainty principle	More precision in one area = less in another	Knowledge limits, trade-offs	Focus vs flexibility in planning	#physics #philosophy
Advanced Concepts	Algorithms	Step-by-step problem-solving procedures	Systematic thinking, automation	Decision trees for hiring process	#computing #math
	Complex Adaptive Systems	Many interacting components that evolve	Understanding emergence, organizations	Ant colonies, market dynamics	#biology #business
	Emergence	Complex patterns from simple interactions	System design, culture building	Twitter conversations from 280 characters	#biology #computing
	Chaos Dynamics	Unpredictable behavior from simple rules	Planning limits, system behavior	Weather prediction limitations	#math #physics
	Irreducibility	Systems that can’t be simplified	Accepting complexity, holistic thinking	Human consciousness can’t be reduced	#philosophy #complexity
	Distributions	How data spreads and patterns within	Data analysis, trend understanding	Normal distribution vs power law	#statistics #research
	Sampling	Selecting representative subset for analysis	Research methodology, testing	A/B testing user behavior	#statistics #research
	Randomness	Unpredictability of outcomes	Planning for uncertainty	Market movements, user behavior	#math #philosophy
	Regression to the Mean	Extreme values move toward average	Performance analysis, expectations	Star employee performance over time	#statistics #sports
	Multiplying by Zero	Any effort × zero factor = zero	Risk identification, critical dependencies	Perfect product with no distribution	#math #productivity
	Equivalence	Two things equal in value/meaning	Value comparison, decision making	Time vs money trade-offs	#philosophy #logic
	Order of Magnitude	Scale expressed as powers of 10	Quick estimation, planning	Rough cost estimates for projects	#math #physics
	Surface Area	Total area object occupies	Exposure analysis, contact optimization	API surface area for security	#geometry #engineering
	Global and Local Maxima	Peak values globally vs locally	Optimization, avoiding local traps	Finding best solution vs good enough	#math #data-analysis
	Pruning	Remove unnecessary components for optimization	Optimization, focus, maintenance	Code refactoring, team restructuring	#biology #computing #business
	Scale Economies	Cost advantages from production expansion	Business growth strategy	Manufacturing cost per unit decreases	#business #economics
	Network Economies	Advantages from large user/partner networks	Platform business models	More users = more valuable for all	#business #economics
	Physical Network Effects	Value from physical infrastructure connections	Infrastructure planning	Telephone networks, cable systems	#business #infrastructure
	Protocol Network Effects	Value from standard adoption	Technology strategy	HTTP, TCP/IP protocol adoption	#technology #standards #business
	Personal Utility Network Effects	Value tied to personal identity/daily use	Product stickiness	Email, messaging apps	#social #technology #business
	Personal Network Effects	Identity/reputation tied to product	Social product strategy	LinkedIn professional identity	#social #reputation #business
	2-Sided Network Effects	Two user classes create mutual value	Marketplace strategy	Uber: drivers and riders	#business #marketplaces
	Data Network Effects	More usage yields more useful data	Data strategy, AI products	Better recommendations with more data	#data #technology #business
	Tech Performance Network Effects	Performance improves with more users	Technology architecture	Peer-to-peer networks	#technology #performance #business
	Social Network Effects	Psychology drives network value	Social product design	Language adoption, belief systems	#social #psychology #business
	Compounding	Value increases exponentially over time	Long-term strategy, investment	Code reuse, relationship building	#finance #investment #health #relationships
	Ergodicity	Statistical properties from single sample over time	Long-term planning, risk assessment	Individual vs ensemble averages	#statistics #economics #physics
	Convexity	Non-linear relationship between variables	Risk management, option value	Interest rate sensitivity	#math #finance #economics
	Kolmogorov Complexity	Shortest program producing given output	Simplicity measurement, theory evaluation	Occam’s razor quantified	#information-theory #complexity #data-analysis
	Surplus Creation	Value generation beyond costs	Business model design	How much value does product create?	#business #economics #strategy
	Surplus Allocation	How created value is distributed	Pricing strategy, stakeholder management	Customer vs company vs employee value	#business #economics #pricing
	Orders of Magnitude	Powers of 10 for estimation	Quick decision-making, planning	Is this a $1K or$ 1M problem?	#math #planning #strategy
	Insufficient Information	Operating with incomplete data	Decision-making under uncertainty	Launch without perfect market research	#decision-making #risk-management
	Cost of Information	Resources vs value of additional data	Research optimization	When to stop gathering data and decide	#economics #research #strategy
	Trade-offs	Choices involve giving up benefits	Explicit decision framework	Speed vs quality in development	#decision-making #strategy
	Focus	Concentrate resources on priorities	Resource allocation, attention management	Say no to good opportunities for great ones	#productivity #strategy
	Bets	Decisions as probability-based investments	Strategic thinking, portfolio approach	Diversify initiatives like investments	#risk-management #strategy
	Bet Sizing	Resource allocation by probability/return	Investment strategy, resource allocation	Size team investment by confidence level	#investment #risk-management
	Customer Need Focus	Center decisions on solving problems	Product development, market fit	Build what customers actually need	#business #product-development
	Learning Engine	Systems generating insights through operation	Continuous improvement, knowledge creation	A/B testing creates learning compounds	#business #innovation
	Hill Climbing	Iterative improvement through testing	Optimization processes, continuous improvement	Local optimization vs global maximum	#optimization #strategy
	Curves	How variables relate over time/scale	Relationship modeling, prediction	Learning curves, adoption curves	#math #strategy
	Compounding Returns	Benefits multiply through reinvestment	Growth strategy, network building	Reputation compounds over time	#finance #strategy

Quick Reference by Use Case

For Startups: ICE-V Framework, Network Effects, Jobs-to-be-Done, Minimum Viable Everything, Customer Need Focus, Asymmetric Bets

For Personal Productivity: Energy Audit, Keystone Habits, Pareto Principle, Environmental Design, Focus, Progress Measurement

For Decision Making: 10-10-10 Rule, Expected Value, Two-Way Door Test, Steel Man vs Straw Man, First Principles

For Risk Management: Barbell Strategy, Black Swan Awareness, Margin of Safety, Kelly Criterion, Antifragile Filter

For Understanding Systems: Feedback Loops, Second-Order Effects, Emergence, Complex Adaptive Systems, Bottlenecks

Meta-heuristic: The best heuristics are memorable, actionable, and generalizable across domains. They compress complex reality into simple decision rules.

If you’re interested in diving further in Mental Models, I highly recommend:

Charlie Munger
fs.blog & The Knowledge Project Podcast & Shane Parrish books
20240817 Taleb mental models
2024-11-16 7 power cheatsheet
Mental Models in Design