Page 20 - Emotions through the eyes of our closest living relatives- Exploring attentional and behavioral mechanisms

Chapter 1
interactions between individuals. Here, there is a role for spontaneous mimicry, which in the field of psychology is defined as the automatic and unconscious imitation of facial or bodily expressions of other individuals (Figure 1ii) (Chartrand & Bargh, 1999). Examples of spontaneous mimicry (henceforth: mimicry) are contagious laughter or crying, but also contagious yawning and self-scratching. Quintessentially a social phenomenon, mimicry is thought to facilitate the perception of emotions in others, as well as the transmission of emotional states between individuals (emotion contagion) (Preston & De Waal, 2002; Prochazkova & Kret, 2017).
Recently, a step-wise evolutionary development of emotion contagion was proposed, starting at multiple individuals showing a similar facial display that is automatically generated by a physiological internal state in response to external events (for instance a fearful face in response to aggressors or predators, or an expression of pain in response to bodily harm) (Palagi et al., 2020). Next, these independent facial displays may have acquired a communicative function by automatically triggering a similar response in others when observed. The function of this system may have been to synchronize activities within the group, for instance by rapidly spreading fear among group members to escape from predators. Importantly, it may have resulted in automatic emotion contagion when the displays reflected emotional states, leading individuals to feel – to a certain extent – what others are feeling. In this way, emotion contagion can help resonate with others, facilitating effective communication and social cohesion (Decety et al., 2012; Preston & De Waal, 2002). For example, spontaneous mimicry of expressions can provide a crucial fitness advantage in parental care, allowing parents to respond to the needs of their offspring (Decety et al., 2012; Roth et al., 2021).
It is important to emphasize that mimicry does not necessarily equate to uninhibited, full-blown copying of behaviors and expressions, as this would hinder individuals from appropriately responding to social situations (e.g., parents would not be able to adequately respond to their infant’s needs if they would always be overwhelmed by sadness when their infant is crying (Mafessoni & Lachmann, 2019)). Rather, mimicry can be subtle, triggering the activation of a corresponding emotional state in oneself, thereby allowing the identification of what someone else is feeling and formation of an appropriate response (Preston & De Waal, 2002). As such, mimicry is considered to be a major building block for more complex socio-cognitive capacities such as empathy (De Waal & Preston, 2017; Koski & Sterck, 2010) and cooperation (e.g., to establish trust between cooperating individuals); two facets that are extensively developed in our species (Tomasello et al., 2012). Thus, through studying mimicry, we
18