Cognitive heuristics, as proffered by Daniel Kahneman and Amos Tversky, are reasoning shortcuts that are useful but flawed. For example, the availability heuristic “infers” an event’s probability, not by performing laborious, ideally rational calculations, but by simply assessing the ease with which similar events can be recalled. Cognitive psychologists presume that cognitive heuristics should be identified with a distinct cognitive mechanism. I argue that this is a mistake ultimately stemming from descriptive rational choice theory’s entangling of descriptive and normative theorizing. (...) Such mechanism-identification is a desideratum for kinds used in answering, “How—in a causal-mechanical sense—do we reason?” However, cognitive heuristics befit a different question, namely, “How—in a contrastive sense—do we reason vis-à-vis ideal rationality?” Clarifying cognitive heuristics’ nature and appropriate explanatory expectations can enhance understanding, provide lessons applicable elsewhere, and illuminate an important episode in the history of cognitive psychological science. (shrink)