Introduction: why and how we mimic emotions

Mimicry and its presumed neurological underpinnings in the form of mirror neurons have become a trending topic in the social, behavioural, and neurosciences during the past decades (e.g. Hess & Fischer, 2013). The notion that minds can be shared by subtly imitating others is a challenging idea that sparks our imagination. For ages, philosophers and scientists have been intrigued by the question of how we come to understandwhat others think. How canwe read theminds of others, how canwe knowwhat they feel and predict how theywill react, and how can we relate to their pain and suffering or join in their victories and pride? Understanding of and empathizing with others appear to form the basis for human bonding and positive social interaction. Whereas shared goals or interests may lead to temporary coalitions and cooperation, understanding others’ feelings and perspectives provides the basis for longterm and enduring social bonds. One crucial aspect of the sharing of minds is the communication of emotions. We cannot be involved in relationships without emotions. We feel and express emotions towards the people we care about, and if people do not elicit any emotions in us, this implies that we feel indifferent towards them. Thus we get angry, irritated, worried, sad, or proud with the people to whom we feel connected; the stronger our concerns, the stronger the emotions, whether negative or positive. Not only do people express their emotions, they also tend to share them with their friends, family and colleagues. The communication of emotions is thus part of many daily interactions as well. A cashier smiles when handing back change, nurses express sympathy to patients, and managers show enthusiasm to motivate employees. The study of emotional expressions has a long tradition in psychology, starting with Darwin and then the seminal work by Paul Ekman; yet, for many years the question mainly focused on observers’ ability to recognize the facial signals of emotion sent by an expresser. In this line of research the perceiver remained passive.