Self-deception's a process of denying or rationalizing away the relevance, significance, or importance of opposing evidence and logical argument. Theorization It's 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 behaviour, and in animal behavior, more generally speaki… (More on Self-deception)