Is the Effect of Behavioral Synchrony on Cooperative Behavior Mediated by Pain Threshold?

Synchronized behavior results in a variety of prosocial behaviors. Research has also implicated that interpersonal synchrony affects pain thresholds, inferred as indicative of endorphin levels. The current study was designed to see if these pain threshold effects mediated the effect of synchrony on interpersonal cooperation. Twenty six individuals were randomly assigned to complete a 30 minute run on a treadmill in either a synchronized or nonsynchronized condition. Pain threshold was measured both before and after exercise as an indicator of endorphin activity. A postrun social investment game measured interpersonal cooperation. Analyses showed that there was a significant direct relationship between condition and cooperation but that this effect was not mediated by pain threshold.