Abstract: Existing research has approached self-deception mainly as an intrapersonal process representing personality traits, motivational biases in information processing, and inconsistencies between explicit and implicit self-systems. Using an evolutionary approach, we treat self-deception as an interpersonal process whereby individuals deceive themselves to better deceive others. This approach advances two new theoretical developments in the understanding of self-deception. We propose that the probabilities of deception detection should affect the likelihood and activation of self-deception, and that a dual-retrieval memory system can be used to operationalize inter-personal self-deception. We first review the existing literature by highlighting three characteristics. First, self-deceptive individuals show contradictory responses between self-report and physiological or behavioral reaction, and these inconsistencies are motivated by the desire to maintain high self-esteem. Second, self-deception is driven by self-enhancing motivations in information processing that includes perceiving, evaluating, and retrieving information. Third, self-deception is also viewed as a personality attribute, representing individual differences in viewing oneself in an overly positive light. These studies also examine affective effects of self-deception and the correlations among emotion, cognition, motivation, and decision-making behaviors. We then present our evolutionary explanation of self-deception which we believe advances the development of this psychological construction and research both theoretically and methodologically. Theoretically, as proposed by the evolutionary biologist, Robert Trivers, self-deception is the result of the “arms race” between deception and deception detection. Because deception is prevalent in all animals including human beings, deception detection has evolved to prevent oneself from being deceived. Cues such as signs of nervousness may be leaked through changes in facial and eye muscle contraction, voice volume and pitch, and other observable physiological and bodily changes. The evolutionary adaptation to avoid these physiological cues of detection is self-deception that leaks out no cues for detection because the individual is unaware of the ongoing deception. Methodologically, we propose a way to test the evolutionary hypothesis about self-deception. Because self-deception evolves to better escape detection, it must respond to social conditions that register the probabilities of deception detection so that individuals should self-deceive when they sense high rather than low probabilities of detection. Social status, moral standing, and the mere number of the deceived, relative to that of the deceiver, represent the detection-registering conditions that should affect the likelihood and activation of self-deception. We also propose a dual-retrieval memory procedure to operationalize self-deception. In the first retrieval that takes place in front of the deceived, the deceiver fails to retrieve encoded information due to the motivation to deceive and to escape detection. In the second retrieval after successful deception has been achieved, the deceiver retrieves the true or full information to achieve fitness gains. The difference between the two retrievals in the self-serving direction proves self-deception.

Key words: self-deception, deception, evolutionary psychology