For many causal endeavors, such as measuring, predicting, and explaining, individuating causal systems plays a crucial role. In this chapter, we focus on the individuation of a specific type of causal systems, what we call cross-cutting systems. These are systems that lack natural boundaries and that are not restricted to the spatiotemporal region of the individuals to which they belong. Based on examples taken from cognitive science and behavioral ecology, we explore how scientists individuate such cross-cutting causal systems.