To explain how people judge that others are lying, an expectancy-violation model is proposed. According to the model, deception is perceived from nonverbal behavior that violates normative expectation. To test the model, 3 experiments were conducted, 2 in the United States and 1 in India. In each experiment, people described acquaintances while exhibiting weird nonverbal behaviors, such as arm raising, head tilting, and staring. Other Ss watched the videotapes of the descriptions and made deception judgments. Consistent with the expectancy-violation model, both American undergraduates and Indian illiterates inferred deception from weird behaviors. Implications of the model are discussed.