Connecting minds and sharing emotions through human mimicry

Facial expressions play a fundamental role in social interactions, as demonstrated by our spontaneous inclination to mimic emotional expressions of others. In this thesis, I take a broad perspective and show that people mimic each other on many more levels than previously thought. Special attention is given to autonomic mimicry (synchrony in heart rate, skin conductance and pupil diameter), which is an underexplored area of research. In the first empirical chapter, I show that pupil mimicry activates social brain regions and when the pupils of interacting partners synchronously dilate, trust is promoted. In the subsequent real-life experiment, I demonstrate that synchrony in heart rate and skin conductance boost attraction between people on a date. In the remaining chapters, I manipulate mimicry with optical illusion and brain stimulation to provide evidence that autonomic and facial mimicry are controlled by distinct neurological pathways. Together, these findings implicate that the tendency to automatically mimic and physiologically align with others can result in emotional contagion – the tendency to ‘catch’ another person’s emotion, which in return encourages trust and affiliation. In sum, this research takes a fundamental step towards the understanding of the neurobehavioral pathways through which mimicry influence (pro)social behaviors.