Bound Together: Social binding leads to faster processing, spatial distortion and enhanced memory of interacting partners.

Feature-binding of objects into perceptual wholes is a well-known phenomenon but until now mostly researched in the context of early vision and low level features, such as colour or proximity. A similar binding process utilising higher level information in order to bind people into interacting groups could facilitate faster processing and enhanced memory retention of social situations. We investigate this possibility in three experiments and show that social interaction is a valid binding mechanism that leads to faster processing in visual search using an odd-quadrant paradigm (Experiment 1). In spatial judgment tasks the same grouping process leads to spatial distortions with interacting individuals being remembered as physically closer (Experiment 2). Finally, we show that memory retention of group-relevant and irrelevant features is enhanced when recalling interacting partners in a surprise memory task (Experiment 3). Alternative explanations on the basis of known principles of grouping as well as low level perceptual features or attention orienting cues were ruled out. We conclude that late-stage grouping processes bind individuals into groups on the basis of their perceived interaction. Identifying the automatic encoding of social interactions in visual search, distortions of spatial memory and object property memory, opens new approaches to studying social cognition and possible practical applications.