In this article, we integrate cultural evolutionary theory with empirical research from developmental psychology, cultural anthropology, and primatology to outline the role of peer learning in the development of complex instrumental skills and behavioural norms. We show that instrumental imitation, contingent teaching, generative collaboration, and the application of selective social learning biases contribute to high-fidelity domain-specific transmission of knowledge between peers. Further, peer learning is persistent across cultures despite norms which favour adult-child transmission in some settings. Comparative research further suggests that children’s greater motivation to interact with and learn from each other sets us apart from other primates. We conclude by outlining avenues for future research, including how individual characteristics, social networks, motivation, cognition, and developmental changes in these may contribute to cultural evolution.