““I suspect that self-deception is similar to its cousins, overconfidence and optimism, and as with these other biases, it has both benefits and disadvantages. On the positive side, an unjustifiably elevated belief in ourselves can increase our general well-being by helping us cope with stress; it can increase our persistence while doing difficult or tedious tasks; and it can get us to try new and different experiences. We persist in deceiving ourselves in part to maintain a positive self-image. We gloss over our failures, highlight our successes (even when they’re not entirely our own), and love to blame other people and outside circumstances when our failures are undeniable. Like our friend the crab, we can use self-deception to boost our confidence when we might not otherwise feel bold. Positioning ourselves on the basis of our finer points can help us snag a date, finish a big project, or land a job. (I am not suggesting that you puff up your résumé, of course, but a little extra confidence can often work in our favor.) On the negative side, to the extent that an overly optimistic view of ourselves can form the basis of our actions, we may wrongly assume that things will turn out for the best and as a consequence not actively make the best decisions. Self-deception can also cause us to “enhance” our life stories with, say, a degree from a prestigious university, which can lead us to suffer a great deal when the truth is ultimately revealed. And, of course, there is the general cost of deception. When we and those around us are dishonest, we start suspecting everyone, and without trust our lives become more difficult in almost every way.””
