Observing third-party ostracism enhances facial mimicry in 30-month-olds.

Mimicry is suggested to be one of the strategies via which we enhance social affiliation. Although recent studies have shown that, like adults, young children selectively mimic the facial actions of in-group over out-group members, it is unknown whether this early mimicry behavior is driven by affiliative motivations. Here we investigated the functional role of facial mimicry in early childhood by testing whether observing third-party ostracism, which has previously been shown to enhance children's affiliative behaviors, enhances facial mimicry in 30-month-olds. Toddlers were presented with videos in which one shape was ostracized by other shapes or with control videos that did not show any ostracism. Before and after this, the toddlers observed videos of models performing facial actions (e.g., eyebrow raising, mouth opening) while we measured activation over their corresponding facial muscles using electromyography (EMG) to obtain an index of facial mimicry. We also coded the videos of the sessions for overt imitation. We found that toddlers in the ostracism condition showed greater facial mimicry at posttest than toddlers in the control condition, as indicated by both EMG and behavioral coding measures. Although the exact mechanism underlying this result needs to be investigated in future studies, this finding is consistent with social affiliation accounts of mimicry and suggests that mimicry may play a key role in maintaining affiliative bonds when toddlers perceive the risk of social exclusion.