Despite extensive work on the evolution of cooperation, the roles of teaching and leadership in transmitting opaque cultural norms—foundations of cooperative behaviors—are underexplored. Similarly, while teaching is well-studied in the evolution of instrumental culture, little attention is given to its role in transmitting opaque culture, such as social values and norms. Transmitting opaque norms often requires teaching, and group leaders are best positioned to transmit them. We explore teaching, leadership, and instrumental versus opaque culture using comparative ethnographic data. We address three questions: Are leaders disproportionately involved in teaching? Does teaching mainly transmit opaque culture? Which age groups are primary learners of opaque cultural norms? Drawing on data from 23 egalitarian foraging societies, we find teaching is more associated with transmitting cultural values and kinship knowledge than subsistence skills and is closely linked to opaque culture and leadership. Leader-biased teaching may drive cooperation, suggesting new research avenues.