Social affiliation refers to the need for social and emotional closeness with others. It derives from a secure attachment with a caregiver in infancy and underpins effective social bonding and relationship formation across the lifespan. Within a personality framework, social affiliation is captured within measures of agreeableness, warmth, and communion. Within psychopathology research, disruptions to social affiliation are evident among adults high on psychopathic traits and children with callous-unemotional traits. We take a multi-method approach to the study of social affiliation, including devising novel methods to assess individual differences in children’s recognition of, expression of, and responsiveness to social affiliation cues, including through vocal (e.g., words) and non-vocal (e.g., laughter, facial emotional expression) stimuli. We also study neural correlates of social affiliation processes.