In four experiments, I examined how a property in one concept is transferred to a second concept during conceptual combination. The results suggest that people instantiate properties: that is, they use a specific representation of a property in the modifier concept to construct a new version of that property that is specific to the combination. If people are instantiating properties, then the modifier property should match its counterpart in the combination to the extent that the modifier and head noun are similar. This observation leads to a variety of predictions (supported by the experiments) about interpretations of similar and dissimilar combinations and about plausibility,preference, and similarityjudgments associated with such interpretations. The results argue against an alternative view of transfer that posits that, in general, abstract representations of properties are copied from one concept to another. In this paper, I describe various processing accounts of instantiation and discuss the implications of the instantiation view for theories of metaphor, conceptual combination, and induction.Many cognitive phenomena involve the use of knowledge ofa domain or concept to understand another. Analogies are one such phenomenon. For example, a child learning about the atom may understand the analogy "the atom is like the solar system" by using knowledge that the planets revolve around the sun in the solar system to infer that electrons revolve around the nucleus ofthe atom. As a second case, understanding noun-noun combinations involves using knowledge of the modifier concept to understand the meaning ofthe combination. For example, understanding kangaroo squirrel involves the use of know1-edge in the modifier noun kangaroo (e.g., knowledge that kangaroos hop) to infer that a kangaroo squirrel is a squirrel that hops. Categorization is a third phenomenon that can be viewed in this way. In categorizing a relatively long, slithering thing making a rattling sound as a rattlesnake, one may use knowledge about rattlesnakes in general to infer that this particular rattlesnake is poisonous and could bite you.A pervasive metaphor in cognitive psychology is that the use of knowledge in one domain to understand another involves "copying" that knowledge from one domain to the other. This view is explicit in many models of analogy and metaphor in which an important component of understanding involves the transfer of knowledge from the source domain to the target domain by a process called copy and substitution