Mimicry of Dynamic Emotional and Motor-Only Stimuli

Simple reciprocal matching behaviors, such as facial mimicry, appear fundamental to social development and interpersonal processes. Identifying mechanisms and moderators of these reactions to others' behaviors is thus important to understanding basic social-emotional functioning and specific clinical syndromes. This experiment extends early electromyographic (EMG) research (Berger & Hadley, 1975) to explore whether rapid, subtle mimicry involves a general motor-matching mechanism (e.g., the mirror neuron system) or if it is related solely to emotional processes. The EMG measured responses to short, dynamic videos of smiling, scowling, stuttering, and arm wrestling. Although mimicry of emotional stimuli was greater than to nonemotional stimuli, participants matched both nonemotional mouth movements and facial expressions of emotions. Mimicry of arm motions was not significant. Individuals' levels of mimicry of emotional and nonemotional were positively correlated. Findings suggest that both motor and affective processes are involved in producing rapid mimetic reactions to dynamic stimuli.