How two share a task: corepresenting stimulus-response mappings.

Previous research has shown that individuals unintentionally adjust their behavior to others by mimicking others' actions and by synchronizing their actions with others. This study investigated whether individuals form a representation of a coactor's task when the context does not require interpersonal coordination. Pairs of participants performed a reaction time (RT) task alongside each other, responding to 2 different dimensions of the same stimulus. Results showed that each actor's performance was influenced by the other's task. RTs on trials that required a response from both participants were slowed compared with trials that required only a response from 1 actor. Similar results were observed when each participant knew the other's task but could not observe the other's actions. These findings provide evidence that shared task representations are formed in social settings that do not require interpersonal coordination and emerge as a consequence of how a social situation is conceptualized.