Modern Darwinist perspective enables to deal with the study of several human phenomena, one of which is deception, that we define as a behaviour unfolded with the deliberate intention of producing or sustaining a state of ignorance or false belief in another person. volutionary Psychology, an emerging area inside Cognitive Science, represents a promising conceptual approach to the study of deception. According to it, knowledge on human mind can be improved by understanding the processes which, during evolution, shaped its rchitecture. This work traces back to the Evolutionary Psychology arguments (for a review see Cosmides & Tooby, 1987; Barkow, Cosmides & Tooby, 1992; Buss, 1995; 1999) and develops the hypothesis that deception is a behaviour underpinned by two psychological echanisms that evolved in response to problems posed by group living: the theory of mind and deontic reasoning.