Getting our act together: an exploration of the mechanisms responsible for the affiliative changes evoked by interpersonal movement

This thesis explores the reasons why dyads whose movements are aligned (i.e., synchronous) report greater levels of affiliation than those whose movements are not (i.e., asynchronous). Though previous research has suggested that outcomes are influenced by self-other overlap, via action co-representation and/or self-other similarity, none has examined this directly, or considered the effects of participants' judgements about their co-actor's relative performance. Previous research has also neglected the fact that dyadic movement can be aligned or misaligned in a variety of ways (e.g., topologically in terms of what movements are made and temporally in terms of when the movements are made), providing little evidence for the mechanisms supporting the alignment-affiliation relationship. Across three experiments, dyads (N=534; 267 dyads) were randomly assigned to perform arm movements that were aligned or misaligned temporally or topologically. Control participants made matching arm movements while facing away from their co-actor, removing visual alignment cues and controlling for the effects of movement. Action co-representation, self-other similarity, and interaction judgments about alignment with the co-actor were tested. Evidence was found favouring the role of meta-judgments, while alignment, but not misalignment, affected affiliation. These findings suggest that high order judgments, and not self-other merging, may be responsible