Mental Model
Free-Floating Rationales
A free-floating rationale is a functional reason that need not be represented by the organism whose feature or behavior it helps explain
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Mental Model
Freemium
A business model that provides a basic offering without a monetary charge while charging for additional features, capacity, service, or access
Mental Model
Freeroll
A term borrowed from games and used informally for an opportunity with favorable upside and little or protected downside
Mental Model
Friction and Viscosity
Physical friction concerns resistance between contacting surfaces, while viscosity concerns a fluid’s resistance to deformation and flow
Mental Model
Friendship Breakup Framework
Friendship breakups — the ending of significant friendships — are among the most painful and least discussed relational losses
Mental Model
Friendship Chemistry Framework
Friendship chemistry refers to the elusive 'click' that makes some relationships feel effortless while others remain cordial but flat, despite similar interests and values
Mental Model
Friendship Maintenance as Active Practice (Not Passive Accumulation)
The behaviors through which people sustain friendships, including supportive interaction, openness, and shared contact
Mental Model
Friendship Maintenance Theory
Friendship Maintenance Theory, drawing on work by William Rawlins and Laura Stafford, identifies the specific behaviors that sustain friendships over time — countering the passive assumption that good friendships 'just h…
Mental Model
Friendships Across Life Transitions
Adult friendships face predictable stress points at major life transitions — and most friendships that end don't end through conflict but through transition-driven divergence
Mental Model
From Linear to Nonlinear
Moving from linear to nonlinear modeling means checking whether a constant-slope or additive approximation misses consequential curvature, thresholds, or interactions in the relevant range
Mental Model
Frugality vs. Earning Power Tradeoff
Two paths to surplus: reducing expenses (frugality) and increasing income (earning power)
Cognitive Move
Functional fit
Check each piece of the system on its own, against the job you gave it. Did that piece deliver the result it was supposed to, at good enough quality, fast enough, and dependably enough? Not the system overall. Each part, separately.
Mental Model
Functional Fixedness
The cognitive bias where you see an object or concept only in terms of its conventional use—unable to perceive alternative functions
Cognitive Move
Functions
Ask what jobs have to get done for a goal to be reached, stated without naming any method. This tier sits between the outcome you want and the specific tactics, so each entry answers "what must happen," never "how."
Mental Model
Fundamental Attribution Error
The systematic tendency to explain others' behavior in terms of their character ('he's lazy,' 'she's brilliant') while explaining our own behavior in terms of circumstances ('I was tired,' 'I got lucky')
Cognitive Move
funnel
Stages stacked in order, each one a subset of the one above, drawn as a bar whose width is how many survive. Nothing rejoins and nothing enters partway down. Because every stage is nested, the widest fall between two bars is the whole diagnosis, and it is often not the stage you have been working on.
Cognitive Move
Future parties
Some people your choice touches aren't in the room because they arrive later in time: your own self in five years, whoever inherits the arrangement, whoever maintains it after you stop. Name them and what they'll be handed.
Cognitive Move
Future self
Step forward in time and ask what the version of you looking back will care about. It filters today's heat through tomorrow's stakes, exposing which details are temporary noise and which consequences you will actually be living with.
Cognitive Move
Gain
Ask how much the signal grows or shrinks on one trip around the circuit. Sign tells you which direction the loop pushes; this tells you how hard, which decides whether the problem explodes in days or creeps for years.
Cognitive Move
Gains Sought
Limit the objective list to the 2 or 3 positive changes that genuinely matter.
Mental Model
Gall's Law (Working Complex Systems Evolve from Simple Ones)
John Gall's principle that complex systems that work invariably evolved from simple systems that worked
Mental Model
Gaman (Endurance with Dignity)
Gaman is the Japanese virtue of enduring the seemingly unbearable with patience and dignity, maintaining composure and self-restraint in the face of hardship without complaint
Mental Model
Gambler's Fallacy
The false belief that past random events affect future random events—that a coin that has landed heads 10 times in a row is 'due' for tails