This article appeared in the September 20, 2015 issue of The New York Times Magazine.
Five years ago, a provocative experiment found that people who bought ‘‘green’’ products at the grocery store were afterward more likely to lie, cheat and hoard prize money, when compared with a control group that didn’t buy such products. Apparently, the authors concluded, ‘‘virtuous acts can license subsequent asocial and unethical behaviors.’’ The study has been widely cited — even in the face of criticism from some scientists over its methods and conclusion — but it didn’t address whether bringing green, reusable bags to the store might influence shoppers’ choices once they got there.
For a study published last month in the Journal of Marketing, Uma Karmarkar, an assistant professor at Harvard Business School, and Bryan Bollinger, an assistant professor at Duke’s Fuqua School of Business, did just that. When a large grocery store in California gave them access to data from its frequent buyers’ program from mid-2005 through mid-2007, a period when the store offered a 3-cent credit for every bag brought in by a shopper to carry items home, they were able to link green bags to actual purchases.
People generally bought more organic produce when they brought their own bags. Presumably they were, in the language of the study, psychologically ‘‘primed’’ by eco-friendly totes to focus on eco-friendly groceries. Yet they also tended to buy extra potato chips, cookies and other treats. Their righteousness ‘‘licensed’’ their self-indulgence, according to the researchers. Additional purchases of organic foods were unrelated to splurges on junk food; indulgent foods only had a clear correlation with bags from home.
Of course, this didn’t show that reusable bags caused changes in shopping behavior. So adult volunteers were asked online to fill a make-believe grocery cart as they would on a routine shopping trip. A portion of the participants were told to imagine bringing their own reusable bags. This group tended to select more sweets than their counterparts who were not told to bring bags — except in the case of those whose real families included children, in which case they skipped the cookies. (Perhaps the impulse to reward oneself for the bags yielded to the desire to feed children well.) Researchers next told some new participants that they were freely choosing to bring their own bags; others were told to pretend that grocery-store policy required them to supply their own bags. Only those who imagined bringing bags voluntarily bought more candy. ‘‘It does seem that you have to decide to bring the bags yourself — not be compelled to bring them — in order to trigger the licensing effect,’’ Karmarkar, the study’s co-author, says. But the takeaway of the study should not be that reusable bags are a liability to those trying to eat well, she adds.
‘‘The lesson,’’ Karmarkar says, ‘‘is that fairly insignificant-seeming choices can have multiple, unexpected consequences on our later behavior, often unconsciously.’’ Feeling virtuous about one decision might be prodding us toward other choices that we would regret in different circumstances.
Related:
- Ask Well: Choosing the Right Grain for Your Morning
- Children Tossing School Lunch Fruits and Vegetables
- Eating on the Move May Lead to Later Overindulging
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