Our Brains Adapt to Dishonesty

Bringing to you one of my favorite Neuroscience papers ever

Gloria Feng
4 min readJan 14, 2020


Pictured: Walter White, from the Netflix show Breaking Bad

Walter White, a high school chemistry teacher, is faced with a terminal cancer diagnosis shortly after his fiftieth birthday. Knowing the burden his illness would have on his family and that he had only a few months left to live, he decides to take matters of supporting his family into his own hands… by entering the underground methamphetamine business. Breaking Bad’s premise is disarmingly innocent at the start. Walter decides to keep just one secret, and we see him wrangling with his conscience when he’s forced to say his first cover-up lie. But once one successful lie leads to another, slowly snowballing into a dozen bigger and scarier lies, viewers start to wonder if they can still recognize the good-natured chemistry teacher that they started with.

Stories like Breaking Bad, many of the big scandals that have made history (Watergate, Enron), and sometimes our own life experiences show us how a series of small lies and transgressions can eventually escalate to unmanageable proportions. How does it happen that small lies seem to grow like they do? How is it that this escalation of dishonesty seems to happen to “good people” too?

A 2016 study from UCL, published in Nature Neuroscience, reveals that there is a neurobiological basis for deception and its gradual escalation. Researchers Neil Garrett and colleagues at UCL used fMRI to show that decreases in the amygdala response over time coincide with escalations of deceptive behavior: our brains desensitize to lying over time.

The researchers invited 80 individuals to participate in the two-part study at UCL, which was formatted as a cooperation game. Each participant had to work with a simulated partner to estimate the number of pennies inside a penny jar. The team is briefly flashed with a thumbnail image of the penny jar, but the participants are privately allowed a more thorough and informative look. Participants then took the role of “Advisor,” responsible for sending advice to inform their virtual partner’s estimate, which was an opportunity to exaggerate or misreport to their teammate if they chose. Importantly, the researchers altered the incentives of the game such that dishonesty may (1) benefit the participant at the expense of the teammate, (2) benefit both, (3) benefit the teammate at the expense of the participant, (4) benefit the participant only without affecting the teammate, (5) or benefit the teammate only without affecting the participant.

Under these conditions, the question was asked: what are the conditions under which we can expect people to tell bigger lies over time? Could it be for altruistic reasons or for personal gain?

Behaviorally, the researchers found that the magnitude of participants’ dishonesty increased steadily over the course of a block only in the self-serving dishonesty conditions. That is, in the conditions in which lying to the teammate either benefited the participant and harmed the teammate, or benefited both players, lying progressively grew in magnitude. The researchers wanted to see if this effect was reflected in brain activity. The emotion-processing region of the brain is called the amygdala and is activated strongly at first when participants tell a lie. Importantly, over the course of repeated lying, participants’ amygdala activations steadily decreased over time, as if they were acclimating to the deception. In further analysis, Garrett and colleagues showed that this blunted emotion effect, indeed, was driving the self-serving dishonesty escalation observed in behavior.

This observation of emotion arousal in the amygdala during deception seems to suggest activation of a guilty conscience when we choose to deceive others. What might this be able to tell us about the condition of psychopathy, with one of the most distinctive features being pathological, remorseless lying? A large body of research on psychopathy indeed finds that deformations of the amygdala and irregularities of emotional function are characteristic of the disorder (Schultz 2016, Yang 2009). The UCL study complements these findings as it ties emotional processing closely to dishonesty. What is startling, though, is that the progressive blunting of emotion they observed, which predicts bigger and bigger lies, is a process that can be triggered in everyone — not only of psychopaths.

In light of these findings, some would wonder: Is there a way that this slippery slope of dishonesty can be avoided?

One of the principal investigators, Tali Sharot, suggests:

“We might want to nudge people away from small lies and [our study] also suggests a way to do so. Because if what carves our dishonesty is emotion, and in the absence of emotion we are more likely to lie, then you might want to try and arouse emotion in people.”

Perhaps if someone were to make Walter White feel more remorseful of his dishonesty, his actions might not have taken as dark of a turn as it did. Let these research findings be a small word of caution to us when we inevitably decide to tell an artful lie: our noses don’t need to grow longer to signal to us that we’ve deceived someone because we’d normally feel it. It would be worth re-examining ourselves and our actions if we notice eventually that we don’t!



Gloria Feng

Writer, Cog-Neuro Research Assistant @ Yale. Presenting my thoughts about self-development and life as a former college student || gloriawfeng.com