Gregory, Eve: Abstarct: Over the past three decades numerous studies from the English-speaking world have pointed to the advantages for young children of family involvement in their literacy development. However, their emphasis has always been firmly and almost exclusively upon parentsworking with children in specific waysand often using school-sanctioned materials. This article investigates the role played by young siblings close in age in each others’ literacy development and argues for a unique reciprocity in learning between older and younger child. Thus it steps outside hitherto recognized paradigms of ‘scaffolding’ and ‘collaborative learning’. This reciprocity of learning I refer to as a synergywhereby siblings act as adjuvants, stimulating and fostering each others’ development. Using examples from Bangladeshi and Anglo children living in East London, the article traces ways in which synergy takes place between dyads through play activities in home and community contexts.