Traditional procedures for detecting deception are based on the global-signs-of-tying model, with its assumption that certain univenal, physiologically mediated signs result from attempts to deceive, independent of content. More recent attempts to detect deception can profitably be viewed from a cognitive rather than affective penpctive: (a) in terms of accuracy of knowledge, in which a person's success at deception regarding a paficular characteristic depends on the extent of his or her knowledge of that characteristic: and (b) in terms of attempts to personalty inffuence the examiner. Such procedures have been successful in detecting simulation in psychopathology, amnesia, neurological disorders, pain, and other areas. They tend to be situation spedffc and to depend on empirically discovered differences between simulators and persons who possess the characteristic.Pinocchio had scarcely told a lie when his nose, which was already long, grew at once twofingers longer. (Carlo Collodi, The Adventures ofPinocchio)The purpose of this article is to present contemporary models for understanding and detecting deceptive behavior, as an alternative to the global-signs-of-lying model that has dominated the field for many years. First, the traditional model is presented and briefly dmussed theoretically and empirically. Next, two contemporary models are