You believe you’re a good person who makes ethical choices. Then you do something that contradicts this belief. You lie to a friend. You cheat on your partner. You screw over a colleague. You’re now holding two incompatible thoughts simultaneously: I’m ethical and I just did something unethical. This creates psychological discomfort so intense that your brain will do almost anything to resolve it. But instead of changing your behavior to match your values, you usually change your values to match your behavior. This is cognitive dissonance, the mental discomfort you experience when holding contradictory beliefs or when your actions...