Are You Laughing at Them or with Them? Laughter as a Signal of In-Group Affiliation

Despite the wide range of theoretical explanations for human laughter, it is generally agreed to function, at least in part, as a social signal. We tested the hypothesis that laughter serves as a signal of group affiliation. Participants viewed a video clip depicting a confederate partner of unknown group affiliation displaying either a neutral expression, a smile, or laughter in response to a joke told at the expense of a member of the in-group...