Why stereotypes don't even make good defaults.

Many concepts have stereotypes. This leaves open the question of whether concepts are stereotypes. It has been argued elsewhere that theories that identify concepts with their stereotypes or with stereotypical properties of their instances (e.g., Rosch, E. (1978). Principles of categorization. In E. Rosch & B. B. Lloyd (Ed.), Cognition and Categorization. Hillsdale, NJ: Lawrence Erlbaum Associates; Smith, E. E., Medin, D. L. (1981). Categories and Concepts. Cambridge, MA: Harvard University Press.) fail to provide an adequate account of the compositionality of concepts (Fodor, J., Lepore, E. (1996). The red herring and the pet fish: Why concepts still cannot be prototypes. Cognition, 58, 253-270.; Fodor, J. (1998). Concepts: Where cognitive science went wrong. New York, NY: Oxford University Press.). This paper extends this argument and reports an experiment suggesting that participants do not assume, even as a default strategy, that complex concepts inherit the stereotypes of their constituents. Thus propositions such as "Baby ducks have webbed feet" were judged to be less likely to be true than propositions like "Ducks have webbed feet." Moreover, manipulation of the type and number of noun phrase modifiers revealed a systematic departure from the unmodified noun's stereotype both with the addition of stereotypical modifiers ("Quacking ducks have webbed feet" versus "Ducks have webbed feet") and with the addition of a second modifier ("Baby Peruvian ducks have webbed feet" versus "Baby ducks have webbed feet"). Thus, in the general case the stereotypical properties of a head noun are systematically discounted when that head noun combines with modifiers. This effect represents a general principle of conceptual combination that argues against the inheritance of stereotypical features of concepts as a default strategy. Instead, we advocate a model of conceptual combination where concepts remain inert under combination, supported by a separate machinery that introduces pragmatic and knowledge-dependent inferences.