A randomized control trial examined the impact of a professional development program on rural teachers' attunement to student social dynamics, and the influence of teacher attunement on students' school experiences. In intervention schools serving Latino and White rural early adolescents, teachers (N = 14) received training on social dynamics and aspects of early adolescent adjustment; control school teachers (N = 12) received no training. Social cognitive mapping procedures assessed and compared students' and teachers' perceptions of peer groups; structured observations assessed teachers' management of social dynamics. Students (N = 225) self-reported their perceptions of the school social-affective context. Intervention and control schools differed on teacher attunement and management of the social environment. Students whose teachers were more attuned to peer group affiliations evidenced improved views of the school social environment. Findings are discussed in terms of attunement as an element of teachers' invisible hand, and for teachers' role in promoting productive contexts for students during the middle school transition. (Contains 2 tables.)