Sharing emotions with other individuals is a widespread phenomenon. Previous research proposed that experiencing intense and similar emotions with other individuals reinforces social bonds. However, several aspects of this phenomenon remain unclear, notably whether social bonding requires the convergence and synchronisation of emotions in the group, and whether these effects generalise across positive and negative emotional contexts. To address these questions, we measured subjective emotional experiences, physiological activity (cardiac, respiratory, electrodermal) and social attitudes in dyads of unacquainted individuals who watched videos in the presence of each other. We manipulated the emotional content of the videos and the type of shared attention between participants, to test for the contribution of interpersonal influence. The results revealed that intense emotions indexed by physiological arousal were associated with the emergence of reciprocal prosocial attitudes within dyads, and that this effect depended on joint attention. We did not observe the convergence and synchronisation of emotions within dyads, which suggests that experiencing similar emotions was not necessary for social bonding. We discuss implications of this study for research on collective effervescence and the social consequences of shared experiences.

Funding provided by: InsermROR ID: https://ror.org/02vjkv261Award Number: Funding provided by: École Normale Supérieure - PSLROR ID: https://ror.org/05a0dhs15Award Number: Funding provided by: Agence Nationale de la RechercheROR ID: https://ror.org/00rbzpz17Award Number: ANR-17-EURE-0017 FrontCog Funding provided by: Agence Nationale de la RechercheROR ID: https://ror.org/00rbzpz17Award Number: ANR-10-IDEX-0001-02 Funding provided by: Agence Nationale de la RechercheROR ID: https://ror.org/00rbzpz17Award Number: ANR-20-CE28-0003 Funding provided by: Agence Nationale de la RechercheROR ID: https://ror.org/00rbzpz17Award Number: ANR-23-CE28-0003