Humans constantly receive sensory input from several sensorymodalities. Via the process of multisensory integration, this inputis often integrated into a unitary percept. Researchers haveinvestigated several factors that could affect the process ofmultisensory integration. However, in this field of research, socialfactors (i.e., whether a task is performed alone or jointly) havebeen widely neglected. Using an audiovisual crossmodalcongruency task we investigated whether social factors affectaudiovisual integration. Pairs of participants received congruent orincongruent audiovisual stimuli and were required to indicate theelevation of these stimuli. We found that the reaction time cost ofresponding to incongruent stimuli (relative to congruent stimuli)was reduced significantly when participants performed the taskjointly compared to when they performed the task alone. Theseresults extend earlier findings on visuotactile integration byshowing that audiovisual integration is also affected by socialfactors.