Ownership status influences the degree of joint facilitatory behaviour.

When engaging in joint activities, humans tend to sacrifice some of their own sensorimotor comfort and efficiency to facilitate their co-actor’s performance. Here, we investigated if ownership - a socio-culturally based non-physical feature ascribed to objects - influences facilitatory motor behavior in joint action. Participants passed mugs that differed in ownership status across a table to a co-actor. Across two experiments, we found that participants oriented the handle less towards their partner when passing their own mug relative to a mug owned by their co-actor (Experiment 1) and a mug owned by the Experimenter (Experiment 2). These findings indicate that individuals plan and execute actions that assist collaborators, but less so if it is the individual’s own property that the partner intends to manipulate. We discuss these findings in terms of underlying variables associated with ownership and conclude that a ‘self-other distinction’ can be instated in the human sensorimotor system.