Trivers’ theory of self-deception (source: wikipedia)
It has been theorized that humans are susceptible to self-deception because most people have emotional attachments to beliefs, which in some cases may be irrational. Some evolutionary biologists, such as Robert Trivers, have suggested that deception plays a significant part in human behavior, and in animal behavior, more generally speaking. One deceives oneself to trust something that is not true as to better convince others of that truth. When a person convinces themself of this untrue thing, they better mask the signs of deception.
This notion is based on the following logic: deception is a fundamental aspect of communication in nature, both between and within species. It has evolved so that one can have an advantage over another. From alarm calls to mimicry, animals use deception to further their survival. Those who are better able to perceive deception are more likely to survive. As a result, self-deception evolved to better mask deception from those who perceive it well, as Trivers puts it: “Hiding the truth from yourself to hide it more deeply from others.” In humans, awareness of the fact that one is acting deceptively often leads to tell-tale signs of deception, such as nostrils flaring, clammy skin, quality and tone of voice, eye movement, or excessive blinking. Therefore, if self-deception enables someone to believe her or his own distortions, they will not present such signs of deception and will therefore appear to be telling the truth.
Self-deception can be used both to act greater or lesser than one actually is. For example, one can act overconfident to attract a mate or act under-confident to avoid a predator or threat. If a person is capable of concealing their true feelings and intentions well, then they are more likely to successfully deceive others.Read less