Fourteen-month-old infants use interpersonal synchrony as a cue to direct helpfulness

Abstract

Musical behaviours such as dancing, singing and music production, which require the ability to entrain to a rhythmic beat, encourage high levels of interpersonal coordination. Such coordination has been associated with increased group cohesion and social bonding between group members. Previously, we demonstrated that this association influences even the social behaviour of 14-month-old infants. Infants were significantly more likely to display helpfulness towards an adult experimenter following synchronous bouncing compared with asynchronous bouncing to music. The present experiment was designed to determine whether interpersonal synchrony acts as a cue for 14-month-olds to direct their prosocial behaviours to specific individuals with whom they have experienced synchronous movement, or whether it acts as a social prime, increasing prosocial behaviour in general. Consistent with the previous results, infants were significantly more likely to help an experimenter following synchronous versus asynchronous movement with this person. Furthermore, this manipulation did not affect infant's behaviour towards a neutral stranger, who was not involved in any movement experience. This indicates that synchronous bouncing acts as a social cue for directing prosociality. These results have implications for how musical engagement and rhythmic synchrony affect social behaviour very early in development.

Effects of Interpersonal Movement Synchrony on Infant Helping Behaviors

“…Gender was counterbalanced across conditions. These rates of bouncing match those used in our previous experiments (Cirelli, Wan, & Trainor, 2014. Our original experiment (Cirelli, Einarson, & Trainor, 2014) used both faster and slower bouncing for different infants in the asynchrony condition.…”

“…A subsequent study replicated the effect of synchronous movement on infants' helping behavior and extended the finding by demonstrating that bouncing synchronously compared to asynchronously with one experimenter does not influence helpfulness directed toward a neutral experimenter uninvolved in the bouncing experience (Cirelli, Wan, & Trainor, 2014). However, in a third study, infants did extend their helpfulness towards a second experimenter, but only if this person was shown to be socially affiliated with the experimenter with whom the infant had been bounced synchronously (Cirelli et al, 2016;Trainor & Cirelli, 2015).…”

“…The procedure and participant sample closely matches those used by Cirelli and colleagues (Cirelli, Einarson, & Trainor, 2014;Cirelli, Wan, & Trainor, 2014. The critical difference is that instead of listening to music during the interpersonal movement phase, infants listened to nonrhythmic nature sounds (such as rushing water, windrustled leaves).…”

“…The experimenter then performed three instrumental helping tasks (3 trials in each task) with the infant. These tasks were developed by Tomasello (2006, 2007) and have been used in our previous studies on infant social behavior following interpersonal synchrony (Cirelli, Einarson, & Trainor, 2014;Cirelli, Wan, & Trainor, 2014.…”

“…For example, 12-month-old infants are more likely to show a social preference for a synchronously over an asynchronously rocking animate toy in a nonmusical context (Tunçgenç, Cohen, & Fawcett, 2015). Furthermore, work in our laboratory has shown that interpersonal synchrony in a musical context actually encourages directed prosociality in 14-month-old infants (Cirelli, Einarson, & Trainor, 2014;Cirelli, Wan, & Trainor, 2014Trainor & Cirelli, 2015). In these studies, infants were held in a baby carrier worn by an assistant, facing an experimenter.…”