My apologies to any PhD students reading this blog. I recently stumbled upon two studies that suggest you can get college students to abandon an unhealthy behavior if you can convince them it's what graduate students do. Apparently grad students are so uncool, college students do not want to be identified with their habits. Even when those habits include junk food and binge drinking, two mainstays of undergraduate life for many.

The studies, published in the Journal of Consumer Research, provide insight into potential strategies for public health. They also reveal how our desire to shape our self-image, and how others perceive us, lead us to make healthy or unhealthy choices.

In the first study, undergraduates read a news article about junk food consumption on campus. The article included the following statement, which varied by one word only:

"A recent survey of campus eating habits found that undergraduates (OR graduate students) are by far the largest consumers of junk food on campus. While eating habits among all campus groups could be healthier, the survey found that the average undergraduate (OR graduate student) consumes almost two times the amount of junk food as an average person on campus."

The researchers had already established that while undergraduates had nothing against graduate students personally, they did not want to be mistaken for one. Graduate students were an "out group." Later, in what the participants thought was an unrelated task, they were able to "go shopping" in a mock store created for the study. Participants who read that graduate students consumed more junk food were less likely to choose unhealthy foods (such as a brownie) and more likely to choose healthy foods (such as an apple).

The second study went a step further and took the experiment into the real world of college life: dorm bathrooms. The researchers designed two different flyers discouraging binge drinking. One took a rational approach, listing a number of scary statistics about drinking, such as "One night of heavy drinking can impair your ability to think abstractly for 30 days." The other flyer showed a graduate student drinking, with the warning, "Lots of graduate students at Stanford drink...and lots of them are sketchy. So think when you drink...Nobody wants to be mistaken for this guy."

The flyers were posted in different dorms that were carefully selected to be as similar as possible. Two weeks after the flyers went up, residents were asked to complete an anonymous survey about drinking. They reported how many drinks they had consumed in the last week. They also answered questions about how they would feel to be mistaken for other groups on campus, including graduate students.

Students in the dorm with the sketchy grad student flyers reported drinking 50% less alcohol than students in the other dorm. The effect was strongest among students who were horrified by the idea of being mistaken for a graduate student.

Were the participants telling the truth? Obviously, we can't know for sure, and the researchers didn't follow them to any parties. It's possible the undergrads didn't want to be mistaken, even in an anonymous research project, for having the drinking habits of a sketchy grad student. But if the reports are honest, this is a fascinating finding about how campuses might make a dent in undergraduate binge drinking. And together, the two studies suggest that if part of you wants to change an unhealthy habit, it may be time to find some very desirable role models (or some very undesirable groups who engage in what you want to quit).

You may not have any strong feelings about graduate students yourself, but it's likely that some of your own health and purchasing choices are influenced by how you wish to be seen by others. Companies and advertisers know this-that's why there are no sketchy grad students in Coca-Cola or Calvin Klein ads. But it's not as simple as wanting to associate with the rich, the famous, or the beautiful. Marketers can convince us that we are being virtuous by buying an environmentally-friendly product, or patriotic by purchasing something Made-in-the-USA. Whole Foods can make us feel like a connoisseur, and Costco can make us feel smarter than the suckers paying full price.

What we eat, drink, wear, drive, and buy is always-at least in part--an attempt to construct a social identity. It lets others know, and lets us imagine, who we are, and who we want to be. Sometimes that helps us make healthy choices, and sometimes it leads us astray.

Next time you're making a choice in the grocery store, consider what identity you're trying to reinforce. And if you want to make a positive change in your life, start looking at your consumer choices as small opportunities to reinforce the healthy, ideal you. Soon it will feel like the "real you."

Research cited: Berger, J., & Rand, L. (2008). Shifting signals to help health: Using identity signaling to reduce risky health behaviors. Journal of Consumer Research, 35. 509-518.

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