Several models of person perception that expectancy violations have both affective and cognitive consequences for the perceiver. Although extant evidence generally supports these claims, the temporal solution of self-report measures has limited researcher's ability to convincingly link underlying physiological processes with observed outcomes. In this study, we examined these issues by measuring brain (event-related brain potentials) and peripheral (facial electromyogram) electrophysiological activity while participants read positive and negative expectancy-consistent, expectancy-violating, expectancy-irrelevant, and semantically incongruent behavioral sentences about fictitious characters. The electromyogram results indicated that negative (but not positive) expectancy-violating behaviors elicited enhanced negative affect as early as 100 to 300 ms poststimulus. The event-related potentials showed enhanced positivities with latency exceeding 300 ms in response to expectancy violations and negative behaviors. Semantically incongruent sentence endings influenced a separate negative component (N400) suggesting fundamental differences between semantic- and behavior-consistency processing. This difference also was evident in participants' recall. Implications for theoretical models of expectancy violation are discussed.