Certain social context features (e.g., maternal presence) are known to increase young children’s exploration, a key process by which they learn. Yet limited research investigates the role of social context, especially peer presence, in exploration across development. We investigate whether the effect of peer presence on exploration is mediated by age or cultural-specific experiences. We test its impact on exploration across development (2-11†years) and across cultures (United States and the Tsimane’, indigenous farmer-foragers in Bolivia). Specifically, peer presence does not boost exploration among young U.S. children and becomes more inhibitory among school-age children. In contrast, peer presence facilitates exploration and provides an additional boost for older Tsimane’ children, who differ from U.S. children in their cultural-specific learning experiences (e.g., formal education), among other differences. We discuss potential cultural factors and mechanisms by which peer presence may boost exploratory behavior. © 2018 Cognitive Science Society, Inc.