Glossary of Terms

By Pritesh Yadav June 21, 2026 17 min read —

5 Whys: A root-cause analysis technique invented at Toyota: ask "Why?" five times in sequence, each time targeting the answer to the previous question, to move from a surface symptom to the underlying cause. Developed by Taiichi Ohno.
Action Line: In BJ Fogg's Behavior Model, the threshold above which a prompt successfully produces a behavior. A person crosses the action line when their combined motivation and ability are high enough at the moment the prompt fires.
Anchoring Bias: The tendency to rely too heavily on the first piece of information encountered when making an estimate or decision, even when that number is irrelevant. First described by Tversky and Kahneman (1974).
Archai: The ancient Greek word used by Aristotle meaning "first principles" — the irreducible starting points of knowledge from which all other conclusions can be derived. The root of the term "first-principles thinking."
Assumption: A belief treated as true without having been actively verified with evidence. Surfacing and testing assumptions is the central discipline of first-principles thinking.
Availability Heuristic: Judging the probability of an event by how easily a vivid example comes to mind, rather than by actual statistical frequency. Plane crashes feel more dangerous than car accidents partly because they are more memorable news events.
B = MAP (Fogg Behavior Model): BJ Fogg's formula from Stanford's Behavior Design Lab: a Behavior happens only when Motivation, Ability, and a Prompt all converge at the same moment. Raising Ability (reducing friction) is usually the most reliable lever because motivation fluctuates unpredictably.
Balancing Loop: A feedback loop that resists change and pushes a system back toward a target or set point — like a thermostat that turns on heating when a room gets too cold and turns it off when the target temperature is reached.
Basal Ganglia: A deep brain structure that stores compressed habit sequences and runs them automatically, freeing the prefrontal cortex for novel thinking. The neurological home of automatic behavior.
Base Rate: The historical average outcome for a class of similar events before factoring in any information specific to the current situation. Daniel Kahneman calls using base rates the "outside view" — a powerful antidote to overconfidence.
Biomimicry: A creative technique that solves human design problems by borrowing strategies that nature has already evolved and field-tested over millions of years. The design of Velcro was inspired by burr seeds; the bullet train's nose shape came from the kingfisher's beak.
Brainstorming: A method of generating ideas rapidly — alone or in a group — by suspending judgment and prioritizing quantity over quality. Coined by advertising executive Alex Osborn in 1953. Works best when evaluation is strictly deferred to a separate session.
Brainwriting (6-3-5 Method): A written variant of brainstorming where six participants each silently write three ideas in five minutes, then pass their paper to the next person who adds to or builds on those ideas. Produces more diverse output than verbal sessions by eliminating social pressure and anchoring.
Causal Loop Diagram: A simple map that shows how variables in a system affect each other through reinforcing (amplifying) and balancing (self-correcting) feedback loops. Used to identify the real leverage points in a problem rather than obvious but ineffective intervention points.
Chunking: The brain's process of converting a sequence of separate conscious actions into a single compressed, automatic unit stored in the basal ganglia. The same process that lets an experienced driver navigate while holding a conversation.
Circle of Competence: The domain of topics where a person has deep, reliable understanding of cause and effect — a concept central to Warren Buffett and Charlie Munger's decision-making. Knowing the edge of your circle is as important as knowing its contents.
COM-B Model: A behavior-change diagnostic framework by Michie, West, and van Stralen: a Behavior occurs when Capability (physical and psychological), Opportunity (physical and social), and Motivation (reflective and automatic) are all sufficient. Used to diagnose exactly which factor is blocking a desired behavior.
Combinational Creativity: Margaret Boden's term for the most common type of creativity: producing something genuinely new by combining two or more existing ideas in a way that has not been done before. Most innovation, from the iPhone to jazz music, is combinational.
Confirmation Bias: The tendency to seek out, notice, and remember only information that confirms what you already believe, while discounting or ignoring contradictory evidence. One of the most pervasive and damaging cognitive biases in decision-making.
Convergent Thinking: The evaluative mental mode of analyzing multiple options and selecting the single best one. The narrowing phase that must follow divergent thinking — done too early, it kills creativity; done too late, it produces analysis paralysis.
Creativity: The ability to produce ideas or artifacts that are both novel (new, not just copied) and useful (serving a real purpose for real people). Not an innate trait but a learnable, process-driven skill.
Dark Pattern: A UI or product design technique that deliberately deceives or coerces users into actions that benefit the business at the user's expense. Coined by UX designer Harry Brignull in 2010. Examples include roach motels, confirmshaming, and hidden fees.
Default: The option that takes effect automatically if the user does nothing. The most powerful nudge in choice architecture because most people never change defaults — making them the single most consequential design decision in any form or flow.
Default Mode Network (DMN): A set of interconnected brain regions (including the medial prefrontal cortex and posterior cingulate cortex) that activate during rest and mind-wandering. Responsible for the incubation effect: background problem-solving that produces sudden insights when the conscious mind is not focused.
Decomposition: Breaking a large, complex problem into its distinct smaller components so each piece can be examined, challenged, and solved independently before being reassembled. A foundational step in first-principles analysis.
Delay: A gap in time between when an action is taken and when its full effect appears in a system. Delays cause decision-makers to overshoot targets, create oscillations, and be surprised by consequences they triggered weeks or months earlier.
Deliberate Practice: Focused, effortful improvement at the edge of your current ability with immediate, specific feedback — as defined by psychologist Anders Ericsson. The mechanism behind expertise in any creative or cognitive domain; distinct from mere repetition.
Diffuse Mode: A relaxed, wandering mental state in which the brain makes loose, unexpected associations across distant regions. The source of most creative breakthroughs and "shower ideas." Must alternate with focused mode for best creative output.
Divergent Thinking: The generative mental mode of producing many varied ideas or solutions by branching outward without judging them. Quantity and variety are the explicit goal. Always precedes convergent thinking in effective creative or design processes.
Endowed Progress Effect: The psychological finding that people exert more effort toward a goal when given an artificial head start, even if the head start is fictitious. The reason onboarding checklists with the first item pre-checked drive higher completion rates.
Feynman Technique: A four-step learning loop developed by physicist Richard Feynman: (1) choose a concept, (2) explain it in plain language as if to a child, (3) find the gaps where your explanation breaks down, (4) simplify and repeat. The gaps reveal exactly what you do not yet understand.
First-Principles Thinking: A reasoning method where you strip a problem down to its most fundamental, verifiable truths — facts that cannot be reduced further — and build conclusions upward from those truths alone, ignoring inherited conventions or what "everyone does."
Fixed vs Growth Mindset: Carol Dweck's terms for two beliefs about ability: a fixed mindset holds that creativity and intelligence are innate and unchangeable; a growth mindset holds that both can be developed through practice, effort, and learning from failure. Growth mindset is consistently associated with higher creative output and resilience.
Flow State: A state of total, effortless absorption in a challenging task, defined by psychologist Mihaly Csikszentmihalyi as occurring when the challenge level closely matches the person's current skill level. Produces the highest quality of focused creative work.
Four Laws of Behavior Change: James Clear's framework from Atomic Habits: make a good habit (1) obvious — clear cue, (2) attractive — appealing craving, (3) easy — low friction response, and (4) satisfying — immediate reward. Invert all four to break a bad habit.
Four-Step Habit Loop (Clear): James Clear's expanded habit model from Atomic Habits: Cue → Craving → Response → Reward. Adds the craving as the motivational engine that converts a cue into action, building on Duhigg's earlier three-part loop.
Habit: An automatic behavior triggered by a consistent contextual cue, stored and executed by the basal ganglia without requiring conscious decision-making each time it runs.
Habit Loop (Duhigg): Charles Duhigg's three-part framework from The Power of Habit: a cue triggers a routine that delivers a reward, which reinforces the loop and makes the cue more powerful over time.
Habit Stacking: A technique where a new behavior is anchored to an existing habit using the formula "After I [current habit], I will [new habit]." Uses existing neural pathways as scaffolding for new ones. Originated in BJ Fogg's research on "tiny habits."
Heuristic: A mental shortcut or rule of thumb that speeds up decisions without requiring full analysis. Useful for routine decisions but produces predictable errors (biases) in novel or high-stakes situations.
Hooked Model: Nir Eyal's four-step product loop from Hooked: Trigger → Action → Variable Reward → Investment. Explains how habit-forming products create automatic user return behavior over repeated cycles without requiring ongoing external marketing.
How Might We (HMW): A reframing phrase popularized by IDEO that turns a problem observation ("People abandon checkout") into an open creative invitation ("How might we make checkout feel effortless?"). The phrasing signals possibility and invites ideation rather than blame or defensiveness.
Identity-Based Habits: James Clear's concept that the most durable habits are tied to who you believe you are ("I am a runner") rather than what you want to achieve ("I want to run a marathon"). Each completed habit repetition is a vote cast for your chosen identity.
Implementation Intention: A specific plan in the form "I will [behavior] at [time] in [place]." Psychologist Peter Gollwitzer's research shows this format doubles or triples follow-through rates versus vague intentions like "I will exercise more."
Incubation: The creative stage in which you deliberately step away from a problem so your unconscious mind can continue making associations in the background — the reason insights often arrive in the shower, on a walk, or just after waking. Part of Graham Wallas's four-stage model (1926).
Inversion: A problem-solving technique, credited to mathematician Carl Jacobi ("invert, always invert") and popularized by Charlie Munger, that works backwards from the failure you most want to avoid to identify what actions to eliminate. Often reveals risks that forward-thinking misses.
Keystone Habit: Charles Duhigg's term for a single habit that, once established, automatically pulls other positive behaviors into place through a cascade of downstream effects. Exercise is the classic example — people who start exercising regularly tend to improve sleep, diet, and focus without specifically targeting those.
Lateral Thinking: Edward de Bono's term for deliberately jumping outside a logical chain to approach a problem from an entirely unexpected angle. Uses provocations, random inputs, and conceptual jumps rather than step-by-step deduction.
Latticework of Mental Models: Charlie Munger's concept of collecting powerful thinking frameworks from many disciplines — physics, psychology, economics, biology — and wiring them together so multiple lenses can be applied to any decision simultaneously, producing judgment that no single-discipline thinker can match.
Leverage Point: A place in a system where a small change produces a large, lasting effect. Identified in Donella Meadows' 1997 essay Leverage Points: Places to Intervene in a System. Meadows ranked leverage points from weakest (tweaking numbers) to most powerful (changing the paradigm the system runs on).
Manipulation Matrix: Nir Eyal's 2×2 ethics framework for product designers: plot a product against two questions — does it improve the user's life, and would the maker use it themselves? Products that score yes on both are facilitators; products that score no on both are exploitative.
Never Miss Twice: James Clear's recovery rule: missing one day of a habit is an accident; missing two days in a row is the start of a new (bad) habit. Always prioritize showing up the next day, even in minimal form, to protect the identity and the streak.
Nudge / Choice Architecture: Richard Thaler and Cass Sunstein's concept from Nudge (2008): the way choices are presented — defaults, framing, ordering, friction — predictably steers decisions without removing any option or changing incentives. A nudge preserves freedom of choice while making better outcomes easier.
Opportunity Cost: The value of the best alternative you give up when you make a choice. Every "yes" is implicitly a "no" to everything else. A concept from economics that, when internalized, sharpens every resource allocation decision.
Paradigm (Meadows): The shared beliefs, goals, and assumptions from which a system was built — the highest-leverage point in Donella Meadows' hierarchy because everything else in the system (rules, information flows, goals) flows from the paradigm. Changing a paradigm is hard but produces the biggest, most lasting change.
Plateau of Latent Potential: James Clear's term for the frustrating early period of habit-building when effort accumulates invisibly below the surface and no visible results appear yet — the point where most people quit, just before the compound growth "breaks through." Identical to the physics of ice melting: nothing seems to happen at 25°C, then everything changes at 0°C.
Po (Provocation): Edward de Bono's lateral thinking tool: state a deliberately impossible, absurd, or reversed version of a situation to shock the mind out of its habitual patterns and into new pathways. "Po: cars have square wheels" might lead to the idea of better suspension systems.
Policy Resistance: The tendency of a system to push back against interventions, neutralizing intended fixes or producing the opposite of the intended result. Classic example: adding more highway lanes to reduce congestion often induces more driving, recreating the congestion.
Pre-Mortem: An evaluation technique where you imagine a solution has already failed and work backwards to identify what caused the failure. Developed by psychologist Gary Klein. Used in Stage 3 of the Thinking Operating System to surface risks that optimism and groupthink hide during planning.
Quantity Precedes Quality: The creative principle, illustrated by David Bayles and Ted Orland's ceramics-class story, that producing a high volume of work leads to better outcomes than attempting one perfect work — because iteration, feedback, and learning compound across attempts.
Reasoning by Analogy: Solving a problem by copying or adapting what already exists — doing things because similar things were done before. Produces incremental improvements efficiently but cannot escape the fundamental assumptions baked into the template it copies from.
Regret Test: An ethics check for product designers proposed by Nir Eyal: ask whether a user will regret taking a designed action the next day, when reflection is possible. If the answer is yes, the design technique should not be used.
Reinforcing Loop: A feedback loop that amplifies whatever is already happening, producing exponential growth (virtuous cycle) or runaway collapse (vicious cycle). The compound interest of systems: small initial advantages grow into large, self-sustaining ones.
Reward Prediction Error: Wolfram Schultz's neuroscience finding that dopamine fires at the moment a cue is recognized — in anticipation of a reward — not merely when the reward arrives. This makes cues themselves feel compulsive, explaining why habit loops are so hard to break once established.
Root Cause: The deepest underlying reason a problem exists — the lever that, if fixed, prevents the problem from recurring rather than merely suppressing its symptoms. Found by iterating through the 5 Whys or by decomposing the system.
SCAMPER: A checklist of seven prompts for systematically mutating an existing idea into new ones: Substitute, Combine, Adapt, Modify/Magnify, Put to other use, Eliminate, Reverse/Rearrange. Developed by Bob Eberle, building on Alex Osborn's earlier checklist.
Second-Order Thinking: Tracing the chain of consequences beyond the immediate first result — asking "and then what?" at least twice. Popularized by Howard Marks and Charlie Munger. The antidote to short-term decisions that produce long-term damage.
Six Thinking Hats: Edward de Bono's parallel-thinking framework: six colored hats represent six distinct modes of thought (white = data, red = emotion, black = caution, yellow = optimism, green = creativity, blue = process). Wearing one hat at a time aligns a group's focus and prevents destructive argument.
Socratic Questioning: A structured method of asking layered questions — about clarity, evidence, assumptions, perspectives, and implications — to expose hidden beliefs and reach more reliable conclusions. Developed by the philosopher Socrates; adapted into a six-category framework for modern critical thinking.
Stock: Any quantity that accumulates or drains over time in a system — water in a bathtub, money in a bank account, customers on a waitlist, trust in a relationship. Stocks change only through flows and are always slower to shift than people expect.
Sunk Cost Fallacy: Continuing to invest in a failing path because of resources already spent on it — even when the rational choice is to stop. The spent resources are "sunk" and cannot be recovered regardless of what you decide now; they should never determine future action.
System 1: The fast, automatic, effortless mode of thinking that handles roughly 95–96% of daily decisions without conscious awareness. Relies on heuristics and pattern-matching; fast and efficient but systematically prone to specific biases. Named by Daniel Kahneman in Thinking, Fast and Slow.
System 2: The slow, deliberate, effortful mode of thinking used for calculation, careful analysis, and considered judgment. Can override System 1 errors but is cognitively expensive and fatigues quickly — which is why defaults and environment design matter so much.
Template Assumption: A belief about how something must be done that has hardened into industry convention — not because it is physically required, but because each generation copied it from the previous one. First-principles thinking exists specifically to expose and challenge template assumptions.
Temptation Bundling: Pairing a behavior you need to do (exercise, expense reports) with something you genuinely enjoy (a favorite podcast, a treat), so the desired activity motivates the necessary one. Studied by behavioral economist Katy Milkman at the Wharton School.
Thinking Operating System: The four-stage synthesis framework from Section 13: (1) understand the real problem using first-principles and systems thinking, (2) generate many solutions using creativity techniques, (3) evaluate rigorously using mental models and pre-mortem, (4) ship the behavior using habit and behavior design.
Two-Minute Rule: James Clear's tactic for breaking resistance to new habits: scale any new behavior down to a version that takes two minutes or less to start. The goal is to make beginning trivially easy, because starting is always the hardest part and momentum builds from there.
Unintended Consequence: A side effect of an action that was not anticipated by the decision-maker — often caused by ignoring feedback loops and delays already active in the system. The classic example is introducing a new predator to control one pest and triggering a cascade that damages the wider ecosystem.
Variable Reward: A payoff that varies unpredictably in size or timing. The most powerful driver of habitual behavior, because uncertainty keeps the dopamine system continuously engaged — the same mechanism behind slot machines, social media feeds, and email notification badges.
Wallas's Four Stages: Graham Wallas's 1926 model of the creative process from The Art of Thought: (1) Preparation — gather deep knowledge of the problem domain, (2) Incubation — step away and let the unconscious work, (3) Illumination — the sudden "aha" moment, (4) Verification — test, refine, and validate the idea.

Continue reading

💡 Thinking Skills

How to Use This Guide

💡 Thinking Skills

How Your Mind Already Thinks (and Why It Misleads You)

💡 Thinking Skills

First-Principles Thinking: Reasoning From the Ground Up