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Study shows uncertainty might be the key to breaking self-deceptive behaviors

UNIVERSITY PARK, Pa. — A fitness tracker mysteriously logs extra steps. A calorie-counting app somehow shows lower numbers. An online quiz score seems surprisingly high. While these scenarios might seem like harmless self-improvement tools, new research reveals they represent a fascinating psychological phenomenon: we often cheat unconsciously simply to feel better about ourselves, even when there’s nothing tangible to gain.

“I found that people do cheat when there are no extrinsic incentives like money or prizes but intrinsic rewards, like feeling better about yourself,” explains Sara Dommer, assistant professor of marketing at Penn State and lead researcher of a groundbreaking study published in the Journal of the Association for Consumer Research. “For this to work, it has to happen via diagnostic self-deception, meaning that I have to convince myself that I am actually not cheating. Doing so allows me to feel smarter, more accomplished or healthier.”

This phenomenon, which researchers call “diagnostic self-deception,” helps explain behaviors that traditional theories about cheating cannot. While previous research focused on cheating for material gain, Dommer’s work examines why people cheat even when the only reward is an enhanced self-image.

Inside the Self-Deception Experiments

Through four carefully designed studies, Dommer and her team revealed how this self-deceptive behavior works in everyday situations.

Calorie Counting Study

One of the most illuminating experiments tackled everyday calorie tracking. Researchers presented 288 undergraduate students with a three-day food diary scenario, including restaurant meals like pancakes, sandwiches, and pasta dishes. Some students received exact calorie counts from restaurant websites (e.g., “450 calories for a short stack of buttermilk pancakes”), while others only saw multiple options ranging from 300 to 560 calories.

The results showed that when students lacked specific caloric information, they consistently chose lower calorie estimates. Importantly, the study was designed so that averaging the provided calorie options would match the true caloric value. Instead, participants routinely selected lower numbers, effectively deceiving themselves about their food choices.

IQ Test Study

Another study examined intelligence self-deception using a cleverly designed IQ test. 195 Amazon Mechanical Turk workers took a multiple-choice IQ test. Half the participants saw the correct answers highlighted after a few seconds, allowing them to cheat if they wished. The other half took the test normally.

Not only did the group with access to answers score significantly higher, but they also predicted they would perform better on a future test where cheating wouldn’t be possible. Even more telling, when offered a monetary bonus for accurate predictions of their future performance, they still maintained these inflated expectations. This suggests they truly believed their enhanced scores reflected their intelligence rather than their ability to see the answers.

Anagram Study

A third study used word scrambles to measure intelligence, presenting participants with jumbled words like “konreb” (broken) and “eoshu” (house).” Some participants had to type their answers immediately, while others saw the correct answers after three minutes and were asked to self-report how many they had solved. Those who could self-report their scores claimed solving significantly more anagrams than those who had to prove their answers in real-time.

Financial Literacy Study

The final study tackled financial literacy with an interesting twist. Before taking a financial knowledge test, some participants read the statement: “MOST Americans rate themselves highly on financial knowledge, but two-thirds of American adults CANNOT pass a basic financial literacy test.” This simple reminder of uncertainty significantly reduced cheating behavior, suggesting that when people question their capabilities in an area, they become more interested in accurate self-assessment than self-enhancement.

The Results: What It All Means

These studies revealed a consistent pattern: when people could cheat without obvious external rewards, they did—but only if they could maintain the belief that their performance reflected real ability. In the calorie-tracking study, participants entered about 244 fewer calories per day when they could choose from multiple options. In the IQ test, those who could see answers scored an average of 8.82 out of 10, compared to 5.36 for the control group.

“Participants in the cheat group engaged in diagnostic self-deception and attributed their performance to themselves,” Dommer said. “The thinking goes, ‘I’m performing well because I’m smart, not because the task allowed me to cheat.’”

Importantly, this wasn’t just about inflating numbers. Participants genuinely seemed to believe in their enhanced performance. They predicted similar high scores on future tests where cheating wouldn’t be possible, rated the assessments as legitimate measures of ability, and showed increased confidence in their capabilities afterward.

This pattern only broke down when participants’ certainty about their abilities was shaken. When reminded about widespread overconfidence in financial literacy, participants’ cheating decreased significantly, and their self-assessments became more modest.

“I don’t think there’s a good cheating or a bad cheating,” Dommer said. “I just think it’s interesting that not all cheating has to be conscious, explicit and intentional. That said, these illusory self-beliefs can still be harmful, especially when assessing your financial or physical health.”

These findings give us a new understanding of why people might fudge their step counts or peek at answers during online assessments. It’s not just about hitting arbitrary goals or earning meaningless badges—it’s about maintaining and enhancing beliefs about our capabilities, even if we have to deceive ourselves to do it.

Even this seemingly harmless form of cheating comes with consequences. When people convince themselves they’re naturally gifted rather than acknowledging their shortcuts, they might avoid seeking necessary help or purchasing beneficial products and services.

“These illusory self-beliefs can be harmful, especially when assessing your financial or physical health,” Dommer warns.

The research suggests a potential solution: “How do we stop people from engaging in diagnostic self-deception and get a more accurate representation of who they are? One way is to draw their attention to uncertainty around the trait itself. This seems to mitigate the effect,” explains Dommer.

Final Takeaway: How to Avoid Self-Deception

So what’s the big takeaway, especially if you believe you might be guilty of such behavior? While self-deception can provide temporary emotional comfort, it’s worth examining our own tendencies toward unconscious cheating.

Take note when you round down calories, peek at answers, or inflate self-assessments. The goal isn’t to eliminate these behaviors entirely — they’re deeply human — but to recognize when uncertainty about our abilities might actually serve us better than false confidence.

As Dommer’s research shows, acknowledging our limitations often leads to more accurate self-assessment and, ultimately, genuine self-improvement. Companies offering self-assessment tools might consider building in reality checks or uncertainty cues to help users maintain more accurate perceptions of their abilities. After all, real growth starts with honest self-awareness, not comfortable self-deception.