Scientists discover how to psychologically inoculate narcissists against dishonesty

A new study published in the journal Personality and Social Psychology Bulletin has found that individuals high in narcissism may be more likely to behave ethically when they are exposed to a specific kind of message designed to prevent rationalizations for bad behavior. Across three experiments, researchers found that people who scored high on narcissism—often associated with entitlement and self-centeredness—were less likely to cheat or lie after receiving a psychological “inoculation” that made unethical justifications seem less persuasive.

The researchers, led by Daniel N. Jones of the University of Nevada, Reno, were interested in exploring a new approach to ethical training, particularly for individuals who are more prone to dishonesty but still care about maintaining a positive self-image. Rather than relying solely on traditional codes of ethics, the team investigated whether an “inoculation” strategy could protect against the rationalizations that often lead to unethical decisions.

The researchers focused on a concept called “moral disengagement”—the psychological process by which people justify unethical behavior in a way that allows them to avoid feeling guilty. Examples include telling yourself that “everyone else does it,” or minimizing the harm done by saying “nobody really gets hurt.” These rationalizations act like self-persuasion, allowing people to maintain a sense of integrity even as they engage in dishonest acts.

The idea behind the inoculation method is to warn people that they will encounter such justifications and then expose them to weakened versions of these arguments, along with counterarguments. Much like a vaccine works by training the body to resist a virus, this psychological inoculation helps the mind build up defenses against future unethical reasoning.

To test this approach, the researchers conducted three separate experiments involving a total of 972 participants. In each study, participants were randomly assigned to one of two conditions. One group read a standard code of ethics—a type of message commonly used in schools and workplaces to promote ethical behavior. The other group read an inoculation message designed to expose and counter common rationalizations for unethical conduct. Each message took about two to four minutes to read.

The code of ethics emphasized the importance of upholding integrity in academic and professional environments. It encouraged people to act with honesty, accountability, and responsibility, and to serve as ethical role models for others by resisting temptation, taking ownership of one’s actions, and promoting a culture of ethical behavior.

The inoculation message, in contrast, warned that unethical behavior, even when it seems harmless or justified, can damage reputations and lead to serious consequences. It explained several common rationalizations people use to excuse bad behavior—such as blaming others, minimizing harm, or using euphemistic language—and countered each one to help individuals resist these faulty justifications.

In the first study, which involved 443 Canadian university students, participants completed a series of personality assessments and answered questions about how likely they were to engage in dishonest behavior in the future. The researchers specifically measured narcissism using two different tools, along with assessments of Machiavellianism and psychopathy. The key finding was that individuals who scored high on narcissism reported stronger ethical intentions after reading the inoculation message, compared to those who read the standard code of ethics. This effect did not appear for those low in narcissism, nor did it appear for individuals high in Machiavellianism or psychopathy.

The second study, which included 224 American business students, took things a step further by measuring actual dishonest behavior. Participants were given a virtual coin-flipping task where they could cheat to earn extra exam credit. If they flipped the coin once and accepted the result, they were considered honest. However, the software allowed them to flip multiple times until they got a favorable outcome. The researchers found that narcissistic participants who received the inoculation were less likely to cheat than those who received the ethics code. Again, no such pattern emerged for the other two traits.

The third study followed 305 participants over time to see whether the inoculation had lasting effects. Participants completed the same kind of initial reading task and were then contacted a week later to report how many lies they had told in the past week. The results showed that individuals high in narcissism who had received the inoculation reported fewer lies, suggesting that the intervention had some durability. Interestingly, this delayed effect was tied more to reductions in dishonest behavior than increases in self-reported honesty.

Across all three studies, the inoculation approach consistently influenced only those high in narcissism. The researchers argue that this makes sense given what is known about narcissistic individuals. People high in narcissism often feel entitled and are motivated by personal gain, but they also care deeply about how they are perceived by others and want to maintain a positive self-image. This internal conflict makes them more likely to rely on rationalizations when they behave unethically—and more receptive to an intervention that targets those rationalizations.

In contrast, individuals high in psychopathy often lack guilt or concern for others and are unlikely to experience internal conflict about their actions, while those high in Machiavellianism may see dishonesty as a strategic tool rather than something to justify.

However, the researchers caution that the inoculation approach is not universally effective. In fact, they found evidence that it might backfire for people who are already internally motivated to be honest or who score low on narcissism. In these cases, exposure to the inoculation message—which highlights common rationalizations—might inadvertently increase awareness of justifications for unethical behavior, even if that wasn’t the intended effect. The same unintended effect was found among participants with low internal motivation to be honest. For these individuals, the inoculation message seemed to prompt more dishonesty compared to the ethics code.

These findings suggest that a one-size-fits-all approach to ethics training may not be optimal. Instead, ethical interventions might need to be customized based on personality traits and motivational factors. People who are already motivated to be ethical may benefit more from standard reminders and ethical codes, while those who struggle with self-serving tendencies—but still care about being seen as good people—may respond better to inoculation messages that challenge their ability to justify dishonest behavior.

“In this research, we found that individuals high in narcissism behaved more ethically when they were exposed to inoculation that prevented them from engaging in moral disengagement tactics,” the researchers concluded. “This finding was exclusive to narcissism and did not apply to the other two Dark Triad traits. Furthermore, the benefits of inoculation seemed exclusive to narcissism, such that those low in narcissism were not more ethical in response to inoculation. In such cases (i.e., high dispositional ethics) merely repeating a code of ethics may be the best approach. Thus, we find not only does inoculation depend on the target audience in this context, but also that individuals high in narcissism may behave ethically under the right circumstances.”

The study, “Inoculating Against Moral Disengagement Creates Ethical Adherence for Narcissism,” was authored by Daniel N. Jones, Rafik Beekun, Julie Aitken Schermer, Kristi Baerg MacDonald, and Josh Compton.