"One of us": Outstanding willingness to help save a single identified compatriot

Willingness to help victims unrelated to oneself, in situations where reciprocity is irrelevant, is a common form of altruism. Prior research showed that people are more willing to extend such help when the victims are identified, particularly when the target of help is a single individual. However, in the present research we found that only when the perceivers regard the victims as belonging to their own in-group, willingness to help a single identified individual is greater than willingness to help a group of individuals: identifying tsunami victims by name increased actual contributions only when the specified target was a single compatriot. The role of perceived shared social group in promoting the victim singularity advantage in contributions was mirrored in ratings of emotions, thus supporting an affective account of helping behavior.