Lie detection: historical, neuropsychiatric and legal dimensions.

Lying and deception are behaviors that have been studied and discussed extensively in the scientific, philosophical and legal communities for centuries. The purpose of this article is to provide a general overview of the literature and thinking to date about deception, followed by an analysis of the efficacy and evolution of lie detection techniques. The first part explores the definitions of lying, from animal behaviorists' perspectives to philosophical theories, along with demographics and research about the prevalence of lying and characteristics of those who lie. This is followed by a discussion of possible motivations for lying, moral arguments about the legitimacy of or prohibition against lying, and developmental theorists' explanations for the growth of a human being's capacity to lie. The first section provides an introduction for the second part, a historical and critical review of lie detection techniques. Early methods, such as phrenology and truth serums are contrasted with more modern-day approaches, such as polygraphy and functional MRIs. Conclusions are drawn about whether technology has really advanced the art of detecting deception. Finally, the article enters a discussion about the law's response to lie detection methods and to deception in general. United States landmark cases, at both the state and federal level, are critiqued with regard to their impact on the admissibility into court of lie detection methods as evidence. Just as the scientific community has been wary of embracing many of these methods, so has the legal community. Through a review of the legal, scientific and pseudo-scientific issues surrounding deception, a greater understanding is reached of the complexity of this universal and morally loaded behavior.