During the brief time students come together for a group tour, museum educators have the opportunity to create a culture of thinking: a place where the group's collective as well as individual thinking is valued, made visible, and actively promoted as part of the ongoing experience of all group members. Creating such a culture is facilitated by understanding the dynamic context of group learning and the ways in which groups enculturate students into patterns of thinking. This article describes eight cultural forces found to shape the culture of group learning in classroom settings, applies this framework to tour observations conducted at three different museums, and explores ways that museum educators might best leverage these forces to cultivate a culture of thinking when conducting school group tours. (Contains 2 figures and 42 notes.)