The concept of affordance, introduced by psychologist James J. Gibson in his ecological theory of perception (1979), describes how objects directly communicate their potential use. According to Gibson, perception is not a complex mental process, but a direct one: information for action is already present in the objects and the surrounding environment.
Possibilities for Action
Affordances indicate the actions that an object or space makes possible. Shape, material, and arrangement suggest how to interact: a handle invites grasping, a flat surface supports weight, a button prompts pressing. To perceive something is to immediately grasp what can be done.
Affordance is not an absolute property of the object but emerges from the relationship between object and user. A tall chair allows an adult to sit, but not a small child; a step may be navigable for a person, but not for a stroller. In this sense, objects communicate action possibilities that are directly perceivable, emerging from the interaction between body, environment, and context.
Affordances and Design
In design, affordances become a tool for non-verbal communication. When an object is well designed, its affordances are clear; when they are ambiguous, they cause confusion or errors. Iconic examples are Norman doors—doors designed so that users perform the wrong action. The error is not the user’s but the design’s, because perceived and actual affordances do not match.
Donald Norman further developed the concept, distinguishing between real affordances (actions that are actually possible) and perceived affordances (actions the user believes are possible). In effective design, these two dimensions align. Even in digital environments, buttons, icons, and links use color, shadow, and visual feedback to make affordances visible: communication occurs at the perceptual level, even before cognitive processing.
Gibson and Norman show that objects speak to the body before they speak to the mind. Shape, materials, and placement in the environment become the language through which the material world communicates with us.
Sources:
• Gibson, J. J. (1979). The Ecological Approach to Visual Perception. Houghton Mifflin.
• Norman, D. A. (2013). The Design of Everyday Things: Revised and Expanded Edition. Basic Books.
• UX Design. (2019). Introduction to the Norman Door.
• Santagostino Magazine. (n.d.). Affordances in Psychology.
• Unicusano. (n.d.). The Ecological Theory of Gibson.
• Psiche Altervista. (n.d.). The Ecological Theory of Perception by Gibson.
