Oxytocin, trust, and trustworthiness: The moderating role of music

Evidence has indicated that the neuroactive hormone oxytocin is essential for prosocial behavior, particularly trust. Exogenous administration of oxytocin has been shown to increase trust in humans. However, one may argue that, except the administration of oxytocin in nonhealthy patient groups (e.g., those with autism or anxiety disorders) to alleviate negative symptoms, external administration of oxytocin has little relevance in normal life. Music, a ubiquitous stimulus in human society, has been shown to increase oxytocin in medical therapy scenarios. Considering this evidence, we conducted a trust game experiment with a sample of healthy humans and investigated music's effects on the (a) trustor's oxytocin levels (blood sample measurement), (b) investment amount (trust behavior measurement), and (c) perception of the other player's trustworthiness (selfreport). The results of our exploratory study show that an increase in oxytocin levels over 40 trials in a trust game increased perceived trustworthiness in the no-music condition but had no impact on investment amount (i.e., trust behavior). Moreover, music had no effect on oxytocin, trust behavior, or perceived trustworthiness. Thus, unlike prior research showing that music listening may increase self-reported trust in another individual, in the present study we found no effect of music on trust (on either a physiological or behavioral level). We surmise that this finding is a result of both the type of music played during task execution and music preferences. Thus, future research must carefully manipulate music features (e.g., pitch, rhythm, timbre, tempo, meter, contour, loudness, and spatial location) and consider a listener's music preferences to better understand music's effects on physiological, perceived, and behavioral trust.