Social effects of interpersonal synchronization during listening to music compared to a metronome: What can we learn from implicit measures?

Interpersonal coordination, such as simultaneous rhythmic movement, is a fundamental way to form socioemotional connections. The social and emotional power of music might further strengthen such interpersonal bonds. Here, we tested if interpersonal synchronization (synchronous vs. asynchronous finger-tapping) affects sympathy and helpfulness more strongly when listening to music compared to a metronome. We tested 40 participants and used an explicit and an implicit measure to assess their social orientation toward a tapping partner (i.e., one of two experimenters). Participants directly rated the friendliness of the experimenter on a 9-point Likert scale. As a more indirect or implicit measure of social orientation, we counted the number of pencils (out of a total of eight) that the participants collected after the experimenter “accidentally” dropped them. After five seconds, the experimenter started to help the participants or collected the pencils herself. Results of the pencil test showed that participants were more helpful toward an experimenter who tapped synchronously compared to asynchronously. Importantly, this result was completely driven by the effect of interpersonal synchrony during listening to music. When listening to music, participants collected 38 pencils (M = 3.80, SD = 3.29) after tapping in interpersonal synchrony compared to only 13 pencils (M = 1.30, SD = 2.67) after tapping asynchronously. No such effect was found for the metronome. The results of explicit ratings of the experimenter’s friendliness, however, did not confirm these effects. The direct ratings might have been more strongly influenced by social desirability or related motivational distortions. Since music is a product of social interactions and might even be the result of evolutionary adaptation, we conclude that especially during listening to music, interpersonal synchrony or asynchrony can fulfill or violate hardwired social expectations. Additionally, we could show that implicit or indirect measures can help elucidate how music, movement and prosocial behavior are connected.