The perception of affordances for the actions of other people (actors) was examined. Observers judged the maximum and preferred sitting heights of tall and short actors. Judgments were scaled in centimeters, as a proportion of the observer's leg length, and as a proportion of each actor's leg length. In Experiment 1 observers viewed live actors standing next to a chair. When judgments were scaled by actor leg length, they reflected the actual ordinal relation between the capabilities of the actors. The perception of affordances from kinematic displays was then evaluated. Observers differentiated tall and short actors, but only when the displays contained direct information about relations between the actors and the chair. It is concluded that observers can perceive affordances for the actions of actors and that kinematic displays can be enough to support such percepts if they preserve actor-environment relations that define affordances.

We studied perception of affordances for the actions of other persons (actors) from kinematic displays. Observers judged the maximum and preferred sitting heights of tall and short actors.Judgments were scaled in centimeters, as a proportion of the observer's leg length, and as a proportion of each actor's leg length. Only when judgments were scaled by actor leg length did they reflect the actual ordinal relation benveen the capabilities of the actors. In addition, observers differentiated tall and short actors only when the displays contained direct information about relations between the actors and the chair. We concluded that observers can perceive affordances for the actions of actors, and that kinematic displays can be sufJicient to support such percepts, if they preserve actor-environment relations that define affordances. We briefly discuss implications of these findings for display design.