The modifier effect in within-category induction: Default inheritance in complex noun phrases

Abstract

Within-category induction is the projection of a generic property from a class (Apples are sweet) to a subtype of that class (Chinese apples are sweet). The modifier effect refers to the discovery reported by Connolly et al., that the subtype statement tends to be judged less likely to be true than the original unmodified sentence. The effect was replicated and shown to be moderated by the typicality of the modifier (Experiment 1). Likelihood judgements were also found to correlate between modified and unmodified versions of sentences. Experiment 2 elicited justifications, which suggested three types of reason for the effect—pragmatics, knowledge-based reasoning, and uncertainty about attribute inheritance. It is argued that the results provide clear evidence for the default inheritance of prototypical attributes in modified concepts, although a full account of the effect remains to be given.

Keywords:

• Concepts
• Prototypes
• Compositionality
• Conceptual combination

Acknowledgements

The authors acknowledge the financial support of City University London, and Erik and Gurli Hultengrens's Foundation for Philosophy (Sweden). We wish to thank Pernilla Asp, John Barry, Herbert Clark, Zachary Estes, Daniel Heussen, Gregory Murphy, Alessia Passanisi, Jeff Pelletier and Lena Wahlberg for fruitful discussions of the research and comments on the manuscript. The authors contributed equally to the research.

Notes

¹Generic sentences include a much wider range of examples, including attributes that are clearly not a part of the content of the concept like “mosquitoes carry the West Nile virus”, and statements about the habits of individuals such as “John smokes a cigar after dinner”. See Carlson and Pelletier (1995) for further discussion.

²Although both “solitary” and “living in cold climates” are attributes, for clarity the term “modifier” will be used to refer to the adjective placed in front of the noun, and the term “attribute” to the property or attribute asserted in the predicate.

³An anonymous reviewer pointed out that an alternative way to elicit relative rather than absolute likelihood judgements would be to place the two sentences side-by-side, but have them each rated for likelihood separately on the 10-point rating scale used before. Since the size of the effect averaged only 1 to 2 points on the scale, our procedure may have risked underestimating the effect. We appreciate this suggestion, but feel that our method of asking for a direct comparison of the two sentences was the best way to set up the task pragmatically for subsequently eliciting justifications where a preference had been expressed.