Explanations of category coherence include that categories reflect feature
correlations in the world, that the human conceptual system is designed to
create systematic categories, and that people have theories about the world
that bind together seemingly unrelated features. The authors have suggeste
d that the need to establish reference in communication also influences cat
egory coherence. This proposal was tested in 2 studies involving a referent
ial communication task. In these studies, consistency was promoted between
individuals by communication, which synchronized the category structures of
different people. Further, people were focused on the commonalities of obj
ects and an the differences related to the commonalities by communication-a
pattern that is compatible with what has been observed in existing categor
ies. These results suggest that categorization research must incorporate co
mmunication tasks into the canon of methodologies used to study category st
ructure.