This is a “bottom-up” paper in the sense that it draws lessons in defining disciplinary categories under study from a series of empirical studies of interdisciplinarity. In particular, we are in the process of studying the interchange of research-based knowledge between Cognitive Science and Educational Research. This has posed a set of design decisions that we believe warrant consideration as others study cross-disciplinary research processes.

There are parallels between Gigerenzer et al.'s emphasis on the rationality of adults' reasoning in terms of simple heuristics and developmental researchers' emphasis on the rationality of children's reasoning in terms of intuitive theories. Indeed, just as children become better at using their theories, so might some people, experts, become better at using simple heuristics.

There are problems with Atran's argument for an innate cognitive module for folk biology. He has been too quick to assume innate origins for what might plausibly be learned. Furthermore, in his characterization he includes aspects – essentialist reasoning and inductions from classes – that are not domain-specific. Finally, his characterization compromises his argument that the module is pretheoretical.

The authors' model reduces the literature on conceptual representation to a single node: “encyclopedic knowledge.” The structure of conceptual knowledge is not so trivial. By ignoring the phenomena central to reasoning about living things, the authors base their dismissal of semantic systems on inadequate descriptive ground. A better descriptive account is available in the conceptual development literature. Neuropsychologists could import the insights and tasks from cognitive development to improve their studies.