communicoupling

The handle offers
a move.

A flat plate affords pushing; a handle affords pulling; a low ledge affords sitting for one body and blocks another. We do not first perceive neutral geometry and then attach every possible use. Environments arrive already structured by possibilities for action.

James J. Gibson called those relations affordances. An affordance belongs neither to the object alone nor to the actor alone. It exists in their fit. Social environments similarly invite, discourage, and distribute action before anyone issues an explicit command.

cue clarityhow visibly one action is invited

72%

action costeffort separating the intended move from alternatives

42%

user diversityspread of bodies, skills, and prior conventions

46%

intended action

—

actors selecting the designed move

ambiguous choice

—

actors whose best options are nearly tied

excluded actors

—

actors for whom no available action clears its cost

The same environment across differently situated actors

gold: intended action by ability band · red: exclusion; a visible cue is not the same as a usable affordance

run 1

Set the conditions

what to try

Distinguish a cue from a possibility.

Align sign and action

Choose Legible invitation. Most actors both perceive and can perform the intended move.

Build a Norman door

Choose Norman door. The mechanism works, but its visible form leaves pushing and pulling too evenly supported.

Design for one body

Choose One-size design. The cue remains clear while rising cost and diversity reveal that legibility does not guarantee access.

the mechanism

Action possibilities are relations, not labels.

The model presents several possible actions to actors whose capacities and learned expectations vary. Cue clarity gives the intended action a perceptual advantage. Action cost subtracts from its usability, especially for actors far from the assumed body or skill. Agents select the highest positive utility; a narrow margin counts as ambiguity, while all-negative utility counts as exclusion.

An affordance differs from the information that signals it. A handle can afford pulling even when nobody notices; a painted false handle can suggest pulling when the door cannot move that way. Design governs behavior by arranging both possibilities and the cues that disclose them.

the social payoff

Environments coordinate by making action easier to see and take.

Architecture, interfaces, forms, seating plans, permissions, and workflow defaults distribute possibilities unevenly. A reply button, locked gate, prefilled field, or round table changes the action landscape before motives and messages enter.

Affordance analysis therefore complements stigmergy: affordances concern what the environment currently makes possible; stigmergy concerns how action modifies that environment for later action.

the mapping

Mechanism ↔ social life.

In the model	In the world
cue clarity	How strongly form or convention indicates a particular action.
action cost	Physical, cognitive, procedural, or social effort required to take it.
user diversity	Variation in bodies, skills, histories, permissions, and expectations.
ambiguity	Several actions appear similarly plausible.
exclusion	The nominal function is not practically available to a situated actor.

where it tears

Limits.

Affordance is used in several incompatible senses.

Ecological psychology, product design, sociology, and computing often mean different things. The page keeps Gibson's relational core while modeling perceived cues separately.

Ease is not consent.

Making an action effortless can manipulate as well as assist. A bright acceptance button and hidden refusal path are affordance politics.

People improvise.

Actors discover uses no designer represented and collectively teach them to others. The action landscape is open-ended, especially in social settings.

Model and evidence

Source. After James J. Gibson, The Ecological Approach to Visual Perception (1979), with perceived cues kept distinct from action possibilities.

Borrowed mechanism. The concepts and mechanisms attributed to the sources above are implemented through the rules described in this explainer.

Implementation choices. The numerical settings, initial conditions and display summaries specify this implementation. They do not establish that the source used the same simulation.

Interpretation. The displayed measures describe the simulated system under its stated rules. Agreement with an illustrative example does not establish an explanation of a particular real-world event.

Calibration. Empirical calibration of these settings has not been established here. Source-specific measured quantities, where cited, are distinct from teaching presets.

Model-to-world mapping

Model element	Interpretation
cue clarity	How strongly form or convention indicates a particular action.
action cost	Physical, cognitive, procedural, or social effort required to take it.
user diversity	Variation in bodies, skills, histories, permissions, and expectations.
ambiguity	Several actions appear similarly plausible.
exclusion	The nominal function is not practically available to a situated actor.

Model version c1750cc5e495.