In contrast to individual tasks, a specific social setting is created when two partners work together on a task. How does such a social setting affect memory for task-related information? We addressed this issue in a distributed joint-action paradigm, where two team partners respond to different types of information within the same task. Previous work has shown that joint action in such a task enhances memory for items that are relevant to the partner’s task but not to the own task. By removing critical, non-social confounds, we wanted to pinpoint the social nature of this selective memory advantage. Specifically, we created joint task conditions in which participants were aware of the shared nature of the concurrent task but could not perceive sensory cues to the other’s responses. For a differentiated analysis of the social parameters, we also varied the distance between partners. We found that the joint action effect emerged even without sensory cues from the partner, and it declined with increasing distance between partners. These results support the notion that the joint-action effect on memory is in its core driven by the experience of social co-presence, and does not simply emerge as a by-product of partner-generated sensory cues.

It has been argued that "we feel the pain of others' ostracism as our own". However, it is unknown whether observed ostracism is as distressing as self-experienced ostracism. We conducted two studies to address this lacuna. In Study 1, participants played or observed an online ball-tossing game, in which they or a stranger were ostracized or included by others. In Study 2, participants imagined themselves or someone else being ostracized or included. Across both studies, self-experienced and observed ostracism had the same negative effect on mood. Also, both self-experienced and observed ostracism evoked need threat, but this effect was slightly lower after observed ostracism. In sum, the findings suggest that we do feel the pain of others' ostracism as our own, consistent with the notion that humans are equipped with a system that detects violations of social inclusion norms in the environment.