The Cognitive Nature of Instantiation

People are easily able to infer that a property true of everything must be true of a particular individual and, similarly, that a property true of an individual is also true of something or other. If everything is made of quarks, then George is made of them, and if George is made of quarks, then something is made of them. The three experiments reported here examine how people make inferences like these that require instantiation - from universal terms (e.g., everything) to particular terms (e.g., George), from particular terms to indefinite terms (e.g., something), or from universal terms to indefinite ones. Results from all three experiments show that it takes people longer to recognize the deductive correctness of arguments that depend on two types of instantiation (e.g., from a universal term to a particular term and from a particular term to an indefinite) than those that depend on two examples of the same type. Experiments 1-3 rule out overall abstractness of the premise or the conclusion as the cause of this difference. Experiments 2 and 3 rule out the possibility that the difference is due to repeated noun phrases. Experiment 3 rules out scope ambiguity as the source of the effect. These findings suggest that people use different cognitive operations to instantiate terms and that switching between them takes time and mental effort.