Adolescent Behavior, Learning, and Knowledge Spillovers: Evidence from a Randomized Experiment

We evaluate a program that shifts the responsibility for establishing positive behavioral norms and reducing classroom disruptions from teachers to students. Covering over 7,500 adolescents from 127 middle schools in Bangladesh, we find that the program significantly improves the classroom social climate, fostering greater cooperation, stronger behavioral norms, and more supportive peer networks. High-performing students emerge as the primary beneficiaries of this improved social climate, exhibiting significantly higher performance in math and verbal tests immediately after the program. A follow-up 1.5 years later reveals that while social climate improvements fade, math gains persist and extend to more students, though they remain concentrated among higher-ability peers. We identify a key mechanism behind this effect: the program strengthens academic support networks among high-ability students, enhancing knowledge spillovers within this group. Our findings suggest that a student-led, cohesive classroom environment creates conditions that help high-ability students excel and facilitate peer learning.