Mental health has a profound impact on how we interact with the world. How it shapes prosocial behaviour during middle childhood, a period crucial for establishing healthy relationships, remains poorly understood. Moreover, whilst child mental health and prosocial behaviour are influenced by caregiving experience more broadly, less is known about how they are shaped by parental reflective functioning (PRF), that is parents' capacity to represent their child's underlying mental states. A longitudinal design, with assessments at baseline and 1 year follow-up, was used with 233 children (111 boys
6-13 years old
54.9% White, 17.2% Asian, 2.58% Black, 14.2% Multiple ethnic groups, 2.58% Other, 8.58% data unavailable). Using path modelling, we examined interrelations between baseline PRF, baseline child internalizing symptoms, and follow-up child altruistic prosocial behaviour. At baseline, PRF was associated with child internalizing symptoms, whilst PRF and internalizing symptoms positively predicted altruistic behaviour 1 year later. These findings suggest that mental health and caregiving experience are key influences on altruistic behaviour in childhood.