Student achievement and engagement are both influenced by the quality of the learning environment. Effective learning environments are characterised by high levels of engagement and interpersonal connection. When learners share a sense of connection to one another and the learning experience, they are said to be experiencing social synchrony, an innate process that facilitates social connection and understanding across groups. Our study explored factors affecting, strategies supporting and indicators of connectedness in the classroom. Using stimulated recall, the subjective experiences and perceptions of three year 9 teachers and 65 students were explored in order to identify the conditions under which social synchrony could be promoted. These conditions could be articulated as four interdependent themes: Familiarity, Affect, Competence, and Student Voice and Choice. The findings have implications for supporting teachers to understand and promote social synchrony in their classrooms, and to enhance learner engagement and achievement through enhancing the quality of the learning environment.