Yawning has a well documented contagious effect: viewing or hearing a yawn—as well as talking or thinking about yawns—causes human subjects to yawn. While comparative ethological and neurological accounts suggest that yawning is a function of primitive biological structures in the brain stem, these analyses do not account for infectious yawning caused by representational and semantic states. Investigating the relationship between perceptual and cognitive avenues of yawn induction affords a unique opportunity to examine how higher level cognitive faculties interact with (...) involuntary or automated processing systems. In this paper, I examine three distinct attempts to reconcile the cognitive properties of contagious yawning with its physiological basis—one neurological, one philosophical, and one functional. None of these accounts are unproblematic, and the most plausible hypothesis for the evolution of contagious yawning does not satisfactorily explain the cognitive iterations of the phenomenon . I argue that the most likely explanation of the contagion links perceptual elements of witnessed yawns to conceptual representations. More centrally, this kind of integrated account has repercussions for general theories of human thought and rationality, and suggests that higher level representational states engage neurophysiological structures in determining human behavior. (shrink)