This chapter discusses key classical and contemporary theoretical and empirical contributions that have enlightened understanding of the sociocultural processes that influence social, cognitive, and psycholinguistic development. The first section reviews some seminal proposals for explaining the relationship between learning and development by the founding father of sociocultural theory, Lev Vygotsky, particularly his concept of the ‘Zone of Proximal Development’. This first section follows up with contemporary work extending some of Vygotsky’s original ideas about how social interactions between experts and novices can propel learning and development through processes such as ‘scaffolding’. The second section reviews some relevant work on the role of peer interactions in enhancing learning and development, centred on children’s ability to collaborate with peers to pursue shared goals and solve problems. The final section sheds light on the relationships between problem-solving, co-regulation, self-regulation, and learning to learn. The chapter closes by presenting a case on the effects of applying the HighScope curriculum in preschool education. This case illustrates some of the central concepts reviewed throughout the chapter. The theoretical and empirical contributions presented provide a solid underpinning for the methodological framework for fostering Communities of Dialogic Inquiry, called Learning Together.