Design history function (i.e., what an artifact was made for) is a central aspect of artifact conceptualization. A generally accepted explanation is that design history is central because it is the root cause for many other artifact properties. In Exp. 1, an inference task allowed us to probe participants causal models, and then to use them when making predictions for Exp. 2. Design history was, in fact, part of what participants viewed as conceptually relevant. Predictions for Exp. 2 were derived using the currently most comprehensive theory about how causal knowledge affects categorization. Our results show that though participants used design history, functional outcome and physical structure to conceptualize artifacts, the effect of design history was independent from knowledge of physical structure and functional outcome. This result is inconsistent with a causal knowledge explanation of design historys conceptual centrality.