<p>In schools, cooperative peer relationships wherein students collaborate on classroom assignments serve as an invaluable resource, promoting equitable exchange and supportive academic development. We investigated whether a teacher’s interpersonal behavior in teacher–student dyads influences a student’s integration into the classroom’s cooperation peer network. Based on social learning and social referencing frameworks, we hypothesized that a student whose teacher displays more communal (e.g., warmth, sensitivity) and less agentic (e.g., guidance, control) behavior towards him or her is more likely to be selected by peers as cooperation partner.&#xa0;Forty-six teachers and their 1,046 third to sixth grade students participated. Using an interpersonal circumplex, teachers rated their behavior towards each student of their class, based on the dimensions of agency (e.g., guidance, control) and communion (e.g., warmth, sensitivity). Sociometric surveys were administered to assess how many classmates preferred to collaborate with each student (indegrees) within the classroom (cooperation peer network). Students’ reading and mathematics competencies, measured via standardized tests, were included as control variables. Results showed that students with higher reading skills received more indegrees. Importantly, and consistent with our hypothesis, students received more indegrees when their teacher displayed higher levels of communal behavior and lower levels of agentic behavior toward them, even after accounting for reading and mathematics competencies. We discuss how teacher interpersonal behaviors characterized by high communion and low agency foster inclusive, supportive classroom environments that promote high levels of peer acceptance and cooperation.</p>