Social media (SM) platforms are frequently used by pre-teen (8-12-year old) consumers for curating their self-identity, developing social relationships and for learning. This paper identifies the building blocks that drive pre-teen SM engagement. We use the Gioia method to analyse interview data collected from 32 pre-teens and parents, in France. Findings show that the primary building blocks are FoMO (Fear of Missing Out) and social inclusive experience, being noticed online, multiplicity, excessive use (without guidelines) and self-regulation. Identity constructs (self-identity and socialidentity) are used to explain SM engagementand to empirically define core conceptual building blocks (aggregate dimensions) that drive SM engagement. We contribute to consumer theory by developing a holistic research framework to examine pre-teen SM engagement. Self-identity and social-identity theories help explain the factors that drive pre-teen SM engagement and explain push/pull influences of parents and schools in encouraging or discouraging certain behaviour. We build on current research into SM usage, drawing from the fragmented existing literature, to reveal causes of both excessive screen-time and SM usage among pre-teen consumers, which may indicate antecedents of future adult behaviour. Practical and regulatory policy issues are considered and addressed.