The effect of different phases of interpersonal synchrony on cooperation


In a paired or group activity people tend to synchronize their movements with others (Sullivan & Blacker, 2017; Tarr et al., 2016; van Ulzen et al., 2008). This unconscious synchronization has been found to influence endorphin activity, referred to as the synchrony effect (SE) (Cohen et al., 2010), which can be assessed with an indirect, non-invasive pain threshold test (Dunbar et al., 2012). This synchrony has also been linked to various prosocial outcomes such as increases to cooperation, attraction to group members and social activity (Wiltermuth & Heath, 2010; Sullivan et al., 2015). Synchronous movements have two main phases; in-phase and anti-phase (Sullivan & Blacker, 2017. To date, only two studies have assessed how synchronized anti-phase movement has influenced endorphin activity via pain threshold and no research has been done to assess the influences on prosocial outcomes. This study analyzed the effect of in-phase and anti-phase drumming on the performance of a novel cooperative task. Fifty-six Canadian university students completed the study with an age range 19-26 (Mage= 21.5). Participants were counterbalanced and randomly assigned to two three-minute synchronized drumming sessions, in-phase and antiphase, followed by a cooperative rollerball maze game. Cooperation was assessed by measuring time to complete the maze game. (Valdesolo et al., 2010). Results showed that there was no significant difference between the two conditions in cooperation (t (51) = -0.83, p>.05). These results suggest that with a task such as drumming, there is no difference between in-phase and anti-phase synchrony on subsequent cooperation.

Acknowledgments: Social Sciences and Humanities Research Council