Inoculating Against Moral Disengagement Creates Ethical Adherence for Narcissism

Increasing honesty is critical in modern society. Moral Disengagement Tactics (MDTs) enable individuals to engage in unethical behavior while avoiding self-criticism, making MDTs a form of self-persuasion. One way to prevent persuasion is inoculation. Across three experiments (<i>N</i> = 972), two preregistered, we randomly assigned individuals to a code of ethics versus inoculation to MDTs condition. Study 1 (<i>n</i> = 443) found that those high in narcissism reported increased ethical intentions in the inoculation condition. Study 2 (<i>n</i> = 224) replicated and extended this effect, finding that individuals high in narcissism were more likely to behave honestly in the inoculation condition. Study 3 (<i>n</i> = 305) was a longitudinal study finding that inoculating those high in narcissism led to fewer lies over the past week's inoculation. None of these interaction patterns emerged for Machiavellianism or psychopathy. Thus, inoculation to MDTs appears effective in reducing dishonesty among those high in narcissism.