Most modern accounts of our mind make use of an analogy that likens our brains to a computational machine. It seems so counterintuitive that our brains would choose to put on a blindfold before computing away, yet we do. We hold the truth to such high standards, and it would only appear logical that the representations we create in our minds are the most effective the closer they get to reality. But in many ways that is not what our brains are working with. From different illusions we know that our senses can easily be fooled. So why go the extra mile to falsify our perceptions even more?

What is self-deception?

From Plato to modern evolutional theorists, many scholars across time and disciplines have been debating about the nature of self-deception. It follows that there are many different definitions of self-deception but roughly they can be categorized into three groups. The simplest of which conceptualizes self-deception as a motivated false belief; a positive illusion. Positive illusions are unrealistically positive beliefs about ourselves or people we are close to that allow us to foster our self-esteem and feel good. The average person thinks more highly of themselves than of the average person. A stricter view proposes that motivated false beliefs are only self-deception if they persist in the face of disconfirming evidence. Someone might believe that the reason why they needed to take a break on a run with friends is not that they are out of shape, but because the route they took that day is particularly steep, although nobody else seemed to be affected by it.

The most demanding definition of self-deception states that a person consciously holds a motivated false belief while at the same time also holding a conflicting and unconscious true belief. Hence a person sincerely beliefs in what they consciously claim but at the same time retain the opposing but true belief without conscious access. In any case, however, self-deception is facilitated by a biased way of processing information that enables the favored conclusion. From selectively attending to and looking for good news to forgetting about the bad. And sometimes we discount contradictory evidence although it makes us look foolish. Like the mother that still believes that her son, who is chowing down on the crayons at daycare, is going to be a gifted artist one day; albeit deep down she knows that it is unlikely.

Convince yourself to persuade somebody else

One argued benefit of self-deception is that it allows us to persuade others. Convincing people is a difficult task. If we lie or are transparent about our own doubts we risk being found out or deemed untrustworthy. However, should we manage to convince ourselves first, lying or withholding some information follows naturally. We do not give away any cues about our internal conflict, since we are not aware of one. Smith and colleagues financially motivated participants to persuade people. They found that the more people were motivated to persuade others, the more they showed a bias in their information processing in a way that aligned with their preferred truth. It appears that the best strategy to convince others was to fool oneself first.

Handling the Truth

Many people would claim that hope is self-deception. In a way, our unrealistic optimistic attitude shelters us from the truth. Self-deception has many psychological and social benefits. Deceiving ourselves, believing we have more control over our future than we do, bolsters our self-esteem. Optimism makes people work harder. Confidence makes other people see and treat us more favorably. Besides what our spirit can endure, there are also limits to what our mind can. Cognitive load describes the amount of mental resources a task demands us to spend on it. Holding multiple beliefs that might even be contradictory at the same time takes up a lot of these resources. Thereby, reducing the amount of cognitive resources left to spend on achieving our goal. Self-deception, that is selectively attending to preferred information and impairing the memorization of unfavorable information, reduces cognitive load.

The Truth is overrated

Reality can be disappointing at best and cruel at worst. Convincing ourselves and others of our preferred version of the truth seems to be a smart strategy to pursue our goals. Although one would think that gathering as much information as possible and engaging in unbiased reasoning is the best long-term strategy. We don’t. In all likelihood self-deception evolved in part to deal with our challenging social environment. We depend on the cooperation of the people around us and our chances of survival increase when we can persuade ourselves to persuade others. This is in line with the now popular argument that we did not develop reasoning to derive the truth but to convince others. Scientists and philosophers alike have been arguing about what reality is and how much access do we even have to it. Knowing how easily we and our senses are deceived, and that we can never know what is true or real anyways, what is the harm in a few little lies?