Abstract
Two studies are described in which the membership ratings of relative clause descriptions of concept conjunctions (such as pets that are also birds) are compared to membership ratings of adjective-noun and noun-noun phrasings of the same conjunctions. The results show that the different phrasings of the conjunction carry the same meaning as reflected in the membership ratings. Furthermore, it is shown that the different phrasings also result in similar patterns of dominance and overextensions. The results also demonstrate that the extent to which the conjunction effect described by Smith and Osherson (1984; Osherson & Smith, 1982; Smith, Osherson, Rips, & Keane, 1988) is found in the data is related not only to the incompatibility of the constituents, but also to the dominance effect. In summary, our results provide evidence for a unitary representation of conjunctive concepts, regardless of the syntactic phrasing of the conjunction.