This chapter presents a discussion on the problem of language, concepts, and metaphors in interdisciplinary collaborations. The chapter relates back to Chap. 2 and the discussions on development to consider some of the problems and possibilities in language practices that involve researchers with different ontological and epistemological backgrounds. Outlining the discussions around words, metaphors, and language use in the Enhancing Children’s Attention project, the chapter shows how all researchers in interdisciplinary collaborations need to learn more about what their collaborators take for granted in terms of ontological, epistemological, and political notions in their respective disciplines and, thus, learn more about the ontological, epistemological, and political blockages inherent in their own disciplinary research practices.