What or when? The impact of anticipated social action effects is driven by action-effect compatibility, not delay.

Motor actions are facilitated if they are foreseeably being imitated rather than counterimitated by social partners. Such beneficial effects of anticipated imitation have been explained in terms of compatibility between one's own actions and their anticipated consequences. Previous demonstrations of these effects might alternatively be explained by consistently faster partner responses for imitative than for nonimitative actions, however. This study contrasts both explanations by using virtual coactors to disentangle the contributions of anticipated action-effect compatibility and anticipated action-effect delay. The data of two experiments support previous theoretical assumptions by showing that the effects of anticipated imitation are indeed driven by compatibility rather than delay.