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Confidence is an essential ingredient of success in a wide range of domains ranging from job performance and mental health to sports, business and combat. Some authors have suggested that not just confidence but overconfidence – believing you are better than you are in reality – is advantageous because it serves to increase ambition, morale, resolve, persistence or the credibility of bluffing, generating a self-fulfilling prophecy in which exaggerated confidence actually increases the probability of success.