Investigating Intergroup Social Affiliation in Early Childhood

Social affiliation-defined by positive social interactions and connections-plays a key role in shaping well-being and health across the lifespan. Social groups are central to how society is organised, and group membership strongly influences social affiliation, often resulting in ingroup preferences-where individuals display a preference for members of their own group. Given the powerful role of group membership in shaping social affiliations, it is critical to understand the developmental origins and environmental factors that influence social affiliation in intergroup contexts. This PhD project aims to investigate how group membership cues shape early-life social affiliation. It uses selective facial mimicry (studies 1 and 2) and the likelihood of inter-ethnic friendship (study 3) as its primary measures of social affiliation. Study 1 utilises neurological biomarkers to examine whether selective facial mimicry in early childhood is driven by a desire to affiliate with ingroup members or by an implicit motivation to learn ingroup-specific behaviours. Study 2 investigates whether children show greater selective facial mimicry of ingroup members after being excluded by ingroup versus outgroup members. It further explores whether this effect is moderated by the diversity of the child's social environment. The final study examines how ethnic group membership influences the likelihood of forming same-ethnic and inter-ethnic friendships in childhood, and how this relationship is moderated by the ethnic composition of the environment. Using a large-scale UK dataset, this study aims to determine whether greater exposure to diversity increases the likelihood of forming inter-ethnic friendships, thereby reducing ethnic segregation in peer networks. Together, these studies offer insight into the mechanisms and factors shaping intergroup affiliation in childhood. The findings may inform educational and parenting strategies to promote inclusivity and support social cohesion.