I Track, Therefore I Snack (Unless I’m a Narcissist)

Written by Marie Brand, PhD Candidate at WU Vienna

We track everything these days, steps, sleep, mood, hydration, thanks to the ever-growing ecosystem of apps and wearables. Self-quantification has become second nature, but it comes with a hidden cost. Behavioral science has long shown that when we excel in one domain, we tend to reward ourselves in another - a phenomenon known as licensing. Hit your 10,000 steps? You might feel justified in indulging in dessert. In their new paper, “The Diverse Impact of Self-Quantification: How Narcissism Prevents Self-Indulgence,” Eline De Vries (Associate Professor of Marketing at Universidad Carlos III de Madrid) and Sahar Karimi (Senior Lecturer in Marketing at University of Liverpool) explore how this spillover plays out and how narcissism, surprisingly, can act as a buffer against it.

For those familiar with social psychology, the licensing effect is well-known. When we do something “good”, like hitting our step goal, we may feel entitled to a reward, even if that reward directly undermines our progress. But what’s less known is how this plays out differently depending on personality traits.

This paper reaffirms the licensing effect, but it adds a new layer of sophistication. For non-narcissistic individuals, self-tracking can backfire. They feel they’ve earned a treat, and that can lead to indulgent behavior.  While social and consumer psychology researchers might nod knowingly, this insight isn’t common knowledge outside the field.

“I was talking to a biologist recently and he had never heard of licensing. So even though it’s well-established in behavioral research, it’s still eye-opening for many.”

- Eline De Vries

The research’s real novelty lies in how narcissism interacts with the licensing effect. Narcissists, driven by a need to maintain their self-image, don’t indulge in the same way. For them, giving in to temptation would threaten the delusion of excellence and superiority they’re trying to uphold. So instead of indulging, they show restraint.

What's narcissism got to do with my step count?

At the heart of Eline and Sahar’s paper lies this surprising twist on the licensing effect: narcissism might protect against the indulgences that self-tracking can trigger in others.

“Narcissists have a strong drive to self-enhance, they’re constantly trying to convince others, and themselves of how great they are. So if they indulge in unhealthy or impulsive behavior after tracking their success, that threatens their self-image. It’s not aligned with the version of themselves they want to project.”

- Eline De Vries

The initial idea of the paper was born: while non-narcissistic individuals are more likely to indulge after tracking success, narcissists might show greater restraint. The data from several studies, including a field study with actual self-tracking of participants’ behavior aligns with this. Narcissistic consumers become better at resisting temptation; self-tracking gives them a kind of external structure that helps them control impulsive tendencies. Eline noted that the review team recognized the paper’s contribution and the strength of its findings, making the review process smooth and enjoyable. In essence, for narcissists, who are typically impulsive, self-quantification can act as a behavioral anchor. It’s not just about tracking progress; it’s about maintaining a consistent image of excellence.

“This was one of the motivations behind the study. Narcissists often don’t seek treatment because they don’t think they have a problem. But their impulsive behavior can be damaging… So I started thinking: what could actually help reduce that impulsiveness, even if they’re not actively looking for help?”

- Eline De Vries

The answer, it turns out, might be hiding in their fitness tracker.

What is narcissism really?

At first glance, narcissism might seem synonymous with vanity or self-obsession. But it is worse than that. Narcissists tend to be impulsive, often displaying aggression, unhealthy consumption habits, and compulsive buying behavior. Their dual need for external validation and internal reassurance makes narcissism complex and often toxic for those around narcissists who are called upon to feed their needs.

“That’s what fascinates me; it’s one of the very few disorders that’s worse for the social environment than for the person suffering from it. And that makes it very difficult to treat because they don’t think they have a problem.”

- Eline De Vries

The authors’ insights are sadly acutely relevant in today’s social media-driven world, where narcissistic traits are becoming more prevalent. Subclinical levels of narcissism are increasing rapidly, the reasons for which are another topic of ongoing research. One factor studied in this area is social media usage. For example, there’s research showing that excessive social media usage could be a driver of narcissism and social media platforms might be especially appealing to people with higher levels of narcissism. It’s all about signaling, about curating the best version of yourself for others to like, follow, and share.

Nudging, Dutch Style

Eline’s research charts new insights at the intersection of personality, self-indulgence, and digital technology. Her work explores how traits like narcissism and compulsiveness shape consumer behavior, especially in the context of digital tools. Her dissertation was on compulsive buying tendencies and how it affects self-control and indulgence.

Eline is drawn to the ways new technologies influence how we consume, behave, and present ourselves. One of her new papers shines a light on cryptocurrencies, which fits into her broader interest in how digital environments shape behavior.

But Eline’s curiosity doesn’t stop at academic theory. During the pandemic, she launched a side project called Fancy Faces, selling handmade, playfully designed face masks. Fancy Faces began as a way to contribute, she explains. She had slack time and wanted to make mask-wearing more fun in the Netherlands where there was a lot of resistance to masking. Her motivation was part behavioral science, part cultural observation. Eline says that Dutch people don’t always follow rules unless they really make sense or you can find a way to overcome their reactance in some other way. Making it more fun for people to wear their masks and adding a self-expressive element was Eline’s way to trying to counteract this reactance against rules typical for the individualistic Dutch.

“Normally I like that rebellious streak, but during the pandemic, it felt different. I wanted to nudge people, just a little, toward something helpful.”

- Eline De Vries

That helpful spirit runs through her academic work: finding subtle ways to influence behavior for the better. Whether it is helping narcissistic consumers become more bearable to those around them, or making rules feel less restrictive, Eline likes to nudge people -gently- toward better choices.

Read the paper

Interested in reading all the details about how narcissism prevents self-indulgence? Read the full paper here.

Want to cite the paper?

De Vries, Eline L.E., Karimi, Sahar (2025), “The diverse impact of self-quantification: How narcissism prevents self-indulgence”, International Journal of Research in Marketing, In Press.

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Meet Eline De Vries

If you could have dinner with anyone, who would it be?

Satoshi Nakamoto. I find crypto fascinating, not in a hardcore “Bitcoin-only” kind of way, but as a phenomenon that clearly fulfills a growing need. No one knows who Nakamoto really is, and I’d love to ask them what motivated the creation of Bitcoin and how they see its impact today.

I’ve explored this in my research too. My other recent IJRM paper looks at crypto philanthropy - how people donate in Bitcoin or Ethereum instead of traditional currencies, and how the value of those coins affects their willingness to give. Turns out, accepting lower-value coins might actually lead to higher donations in real-world currency. So yes, crypto is part of my academic work, but also something I genuinely enjoy thinking about.

What would you do if you were not in academia?

I would say I would be an actress, actually. Acting taps into something completely different, more emotional, less analytical. After my PhD, I took a summer acting course in the U.S. and absolutely loved it.  I’m especially drawn to psychologically complex roles, characters you really have to understand from the inside out. It’s about stepping into someone else’s experience and figuring out why they behave the way they do.

What do you like to do in your free time?

I try to keep things sustainable—for myself and my family. That balance is important. During the pandemic, I got into sewing, which was surprisingly relaxing. You’re hyper-focused on something small, and it clears your mind. I don’t do it much anymore, though.

These days, I love traveling and trying out new food, ideally both at once. Discovering new cuisines is one of my favorite things. Turkish food, especially in Istanbul, is incredible. It’s underrated globally, but anyone who really knows food rates it very high.

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This article was written by

Marie Brand

Ph.D. candidate at the WU, Vienna