Dispositions for prosociality undergo major changes during adolescence, a period of increased sensitivity to peer influenceand incipient internalization of societal norms. However, the proximate mechanisms favoring the development of prosocialpreferences are poorly understood. Here, we show that high-status peers affect adolescents prosocial decision making.Participants repeatedly chose to either donate money to a charity or keep it for themselves and could revise their decisionupon observing the (opposite) decisions of either a high-status or low-status peer from their classroom. Participantstended to conform to peer behavior, reversing their initial preference. Importantly, this pattern was especially strong whenobserving high-status peers, suggesting that norm signalling from high-status peers can be instrumental for the diffusionof prosocial behavior. Using a novel incentivized paradigm in a naturalistic setting, we provide experimental evidencefor the role of high-status peers in the development of prosocial preferences and outline a potential path for interventionsaimed at spreading prosocial norms.