Expecting to lift a box together makes the load look lighter

TLDR

Individual action abilities influence how people perceive spatial properties of objects. The study examined how intending to lift an object with another person shapes perceived weight. Four experiments had participants judge box weight while expecting to lift alone or with a co‑actor, who varied in health status. When a healthy co‑actor was anticipated, participants perceived the box as lighter, showing that expected effort modulates perceived object properties in joint action.

Abstract

The action abilities of an individual observer modulate his or her perception of spatial properties of the environment and of objects. The present study investigated how joint action abilities shape perception. Four experiments examined how the intention to lift an object with another individual affects perceived weight. In Experiments 1, 2a, and 2b, participants judged the perceived weight of boxes while expecting to lift them either alone or with a co-actor. In Experiment 3, the co-actor was healthy or injured. Participants intending to lift a box with a co-actor perceived the box as lighter than participants intending to lift the same box alone, provided that the co-actor appeared healthy and therefore capable of helping. These findings suggest that anticipated effort modulates the perception of object properties in the context of joint action. We discuss implications for the role of action prediction and action simulation processes in social interaction.