From the perspective of philosophy, the idea of humans lying to themselves seems irrational and maladaptive, if even possible. However, the paradigm of cognitive modularity admits the possibility of self-deception. Trivers argues that self-deception can increase "tness by improving the e!ectiveness of inter-personal deception. Ramachandran criticizes Trivers' conjecture, arguing that the costs of self-deception outweigh its bene"ts. We "rst modify a well-known cognitive modularity model of Minsky to formalize a cognitive model of self-deception. We then use Byrne's multi-dimensional dynamic character meta-model to integrate the cognitive model into an evolutionary hawk}dove game in order to investigate Trivers' and Ramachandran's conjectures. By mapping the in#uence of game circumstances into cognitive states, and mapping the in#uence of multiple cognitive modules into player decisions, our cognitive de"nition of self-deception is extended to a behavioral de"nition of self-deception. Our cognitive modules, referred to as the hunger and fear daemons, assess the bene"ts and the cost of competition and generate player beliefs. Daemon-assessment of encounter bene"ts and costs may lead to inter-daemonic con#ict, that is, ambivalence, about whether or not to "ght. Player-types vary in the manner by which such inter-daemonic con#ict is resolved, and varieties of self-deception are modeled as type-speci"c con#ict-resolution mechanisms. In the display phase of the game, players signal to one another and update their beliefs before "nally committing to a decision (hawk or dove). Self-deception can a!ect player beliefs, and hence player actions, before or after signaling. In support of Trivers' conjecture, the self-deceiving types do outperform the non-self-deceiving type. We analyse the sensitivity of this result to parameters of the cognitive model, speci"cally the cognitive resolution of the players and the in#uence of player signals on co-player beliefs.
2001 Academic Press 2 I naturally said to him, since I am an enthusiastic chess player, &&You mean, the theory of games like chess.'' &&No, no,'' he said, &&Chess is not a game. Chess is a well-de"ned form of computation. You may not be able to work out the answers, but in theory there would be a solution, a right procedure in any position. Now real games,'' he said, &&are not like that. Real life consists of blu$ng, of little tactics of deception,