Previous studies have shown that behavioral synchronization with others positively affects various psychological and behavioral variables. However, no consistent view has been given on the effects of synchronization, as different researchers tend to use different indicators. In light of this, the purpose of this study was to comprehensively examine the effects of synchronization by using multiple psychological and behavioral indicators that have been shown to be associated with synchronization, as dependent variables. We set up conditions in which the upper arm motion was synchronous and asynchronous between two participants who maintained a controlled gaze. The results showed that synchronization of behavior with others was not an effect and not a mediated effect by psycho-logical variables; however, it had a direct effect on behavioral indicators. Specifically, compared with the asynchronous condition, the synchronous condition resulted in closer interpersonal distance between participants and greater cooperation with others in the prisoner’s dilemma game.