To what extent can teacher-student dyadic interactions modify the hierarchy of student performances within a single class? To answer this insufficiently researched question, the authors conducted two parallel studies involving 33 Grade 5 classes in France (759 students) and 15 Grade 5 classes in Luxembourg (243 students). Interactions were observed during whole-class lessons. Posttest scores were analyzed using multilevel models controlling for five level-1 variables and two level-2 variables. The authors did not find any effect of dyadic interactions on relative student performance in mathematics or in language (French or German), in France or in Luxembourg. This result is interpreted in terms of both the public character of dyadic interactions in whole-class settings and the class management functions of these interactions.