title: Evidence for unintentional emotional contagion beyond dyads.
abstract: Little is known about the spread of emotions beyond dyads. Yet, it is of importance for explaining the emergence of crowd behaviors. Here, we experimentally addressed whether emotional homogeneity within a crowd might result from a cascade of local emotional transmissions where the perception of another's emotional expression produces, in the observer's face and body, sufficient information to allow for the transmission of the emotion to a third party. We reproduced a minimal element of a crowd situation and recorded the facial electromyographic activity and the skin conductance response of an individual C observing the face of an individual B watching an individual A displaying either joy or fear full body expressions. Critically, individual B did not know that she was being watched. We show that emotions of joy and fear displayed by A were spontaneously transmitted to C through B, even when the emotional information available in B's faces could not be explicitly recognized. These findings demonstrate that one is tuned to react to others' emotional signals and to unintentionally produce subtle but sufficient emotional cues to induce emotional states in others. This phenomenon could be the mark of a spontaneous cooperative behavior whose function is to communicate survival-value information to conspecifics.
authors.affiliation: Laboratoire de Neurosciences Cognitives (LNC), INSERM U960, and Institut d'Etudes de la Cognition (IEC), Ecole Normale Supérieure (ENS), Paris, France. guillaume.dezecache@ens.fr
authors.forename: Guillaume
authors.initials: G
authors.lastname: Dezecache
authors.forename: Laurence
authors.initials: L
authors.lastname: Conty
authors.forename: Michele
authors.initials: M
authors.lastname: Chadwick
authors.forename: Leonor
authors.initials: L
authors.lastname: Philip
authors.forename: Robert
authors.initials: R
authors.lastname: Soussignan
authors.forename: Dan
authors.initials: D
authors.lastname: Sperber
authors.forename: Julie
authors.initials: J
authors.lastname: Grèzes
mesh_terms: D000293:Adolescent; D000328:Adult; D003299:Cooperative Behavior; D003463:Cues; D005149:Facial Expression; D005152:Facial Muscles / Q000502:physiology; D005239:Fear / Q000523:psychology*; D005260:Female; D006240:Happiness; D006801:Humans; D008297:Male; D008399:Mass Behavior; D010775:Photic Stimulation; D012938:Social Perception; D055815:Young Adult