Joint attention, shared goals, and social bonding.

There has recently been interest in the ways in which coordinated movements encourage coactors to feel socially closer to one another, but this has generally overlooked the importance of necessary precursors to this joint action. Here we target two low-level behaviours involved in social coordination that may mediate a relationship between joint actions and social bonding, namely joint attention and shared goals. Participants engaged in a simple reaction time task while sitting next to a partner performing the same task. In a joint attention condition, both participants attended to stimuli presented on the same half of a computer screen, while in a control condition, they attended to opposite sides of the computer screen. Shared goals were manipulated by giving participants the instruction to keep below a threshold score for both individual response times and accuracy (individual goal), or their joint mean response time and accuracy (i.e., averaging their mean response time and accuracy with that of their partner: shared goal). Attending to the same side of the screen led to higher ratings on a composite social bonding index directed towards a partner, while shared goals did not cause any effects on partner ratings. Joint attention was sufficient to encourage social closeness with an interaction partner, which suggests that any activities which encourage attending to the same point in space could have some influence on how connected coactors feel about one another.