Schooling is widely acknowledged as an apparatus to legitimate and reproduce social inequality. However, its internal mechanisms through which it perpetuates social segregation remain under explored. Drawing on Bernstein's concept of recontextualization, this study takes various forms of communication in classroom practices as the indicator to recover their underlying regulative principle. Thirty-four classroom videotapes from three stream schools in China were coded and analyzed. The results show class disparities in the duration of peer interactions, the quality of classroom interaction, and the teachers’ instructional support across three streams of schools. Teachers from higher-stream schools allocate more time to peer interaction, which correlates with enhanced classroom interactional quality and teachers’ instructional support. In addition, the duration of peer interaction acts as a mediator, influencing the quality of interaction and teachers’ instruction, which are the direct predictors of students’ school achievements. These findings suggest that social class differences are transformed and legitimized into differential durations of peer interaction, which mediate classroom quality and then stratify students’ school achievements, ultimately reproducing social stratification.
