Abstract: The notion of a thematic role has been an important one in linguistic theories concerning the syntax/semantics interface (Fillmore, 1968), but their effects on high-level cognition remain relatively unexplored. Thematic roles,like AGENT and PATIENT, are said to be linked with specific grammatical positions like that of subject and direct object. Here we ask if the link between grammatical subjects and the thematic role AGENT might create an intentionality bias for subjects. We tested this in a series of studies examining both response times and accuracy. These studies reveal a quick and reflexive bias to treat grammatical subjects (but not prepositional objects or direct objects) as being more intentional than they actually are. However, this bias may be overcome when people are encouraged to reflect on their true knowledge. Broader implications of our findings for research in psychology and linguistics are discussed.