Two dogmas of conceptual empiricism: implications for hybrid models of the structure of knowledge.

Concepts seem to consist of both an associative component based on tabulations of feature typicality and similarity judgments and an explanatory component based on rules and causal principles. However, there is much controversy about how each component functions in concept acquisition and use. Here we consider two assumptions, or dogmas, that embody this controversy and underlie much of the current cognitive science research on concepts. Dogma 1: Novel information is first processed via similarity judgments and only later is influenced by explanatory components. Dogma 2: Children initially have only a similarity-based component for learning concepts; the explanatory component develops on the foundation of this earlier component. We present both empirical and theoretical arguments that these dogmas are unfounded, particularly with respect to real world concepts; we contend that the dogmas arise from a particular species of empiricism that inhibits progress in the study of conceptual structure; and finally, we advocate the retention of a hybrid model of the structure of knowledge despite our rejection of these dogmas.