Facial mimicry predicts preference.

The human capacity for facial mimicry plays a vital role in social bonding and emotional comprehension. This study investigates the role of facial mimicry in preference formation. To do so, One-hundred and six participants, comprising of fifty-three dyads engaged in a preference-based paradigm where in each trial participants had to listen and then choose between two movie synopses, while their facial muscle activity was recorded using wearable facial electromyography (EMG) electrodes. In the first part of the experiment, one participant read aloud the two synopses, and in the second part both participants listened to a pre-recorded actress. Our findings revealed that speaker-listener facial mimicry of muscles associated with positive emotions was linked with increased likelihood of selecting that synopsis. In addition, listener's choice was better predicted by speaker-listener's facial mimicry than by individuals' facial expressions alone. Notably, these results were maintained even when only smiling mimicry was measured with the pre-recorded actress, highlighting the robustness of this effect. Our findings reveal the central role facial mimicry plays in preference formation during social interaction.