A great article from The Skeptic's Dictionary about self self-deception. Confirmation bias is something that we all have a tendency for. And knowing this, we should be forewarned so that we will make a concerted effort to nullify this tendency in our search for truth:
Self-deception is the process or fact of misleading ourselves to accept claims about ourselves as true or valid when they are false or invalid. Self-deception, in short, is a way we justify false beliefs about ourselves to ourselves.
When philosophers and psychologists discuss self-deception, they usually focus on unconscious motivations and intentions. They also usually consider self-deception as a bad thing, something to guard against. To explain how self-deception works, they focus on self-interest, prejudice, desire, insecurity, and other psychological factors unconsciously affecting in a negative way the will to believe. A common example would be that of a parent who believes his child is telling the truth even though the objective evidence strongly supports the claim that the child is lying. The parent, it is said, deceives him or herself into believing the child because the parent desires that the child tell the truth. A belief so motivated is usually considered more flawed than one due to lack of ability to evaluate evidence properly. The former is considered to be a kind of moral flaw, a kind of dishonesty, and irrational. The latter is considered to be a matter of fate: some people are just not gifted enough to make proper inferences from the data of perception and experience.
