STEVE INSKEEP, HOST:
We would like to imagine that we think for ourselves. The truth is more complicated. Research suggests that we take cues, often unconsciously, from the world around us. Now, there is a way to harness hidden influences to encourage healthier eating, as NPR's Shankar Vedantam first told us this spring.
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SHANKAR VEDANTAM, BYLINE: Researchers know that people often tend to follow rules and signs. When you sign up for a retirement account, for example, you're often told, look, here's a basket of stocks, and here's a basket of bonds. And just doing that can help people balance the risk in their portfolios because it prompts them to choose some things from each basket. The researchers Brian Wansink, Dilip Soman, Kenneth Herbst and Collin Payne asked what would happen if you did the same thing with grocery carts? Can you help people keep the rules of healthy eating in mind as they shop for their groceries? So what they did was they partitioned grocery carts in stores in the United States and Canada. In some cases, they had yellow duck tape run through the middle of the cart, and they put up signs saying this part of the cart is for fruits and vegetables, this part of the cart is for other kinds of food.
INSKEEP: Oh, just a little reminder. I should get some of each and not all of one thing.
VEDANTAM: Exactly, and they found that the simple act of partitioning the grocery cart led people to buy more fruits and vegetables.
INSKEEP: So if they started making the fruit compartment larger or smaller, did that change the amounts of food people bought?
VEDANTAM: In fact, they did exactly that, Steve. They varied the size of the partition, and they found that the larger the size of the partition for the fruits and vegetables, the more fruits and vegetables people bought. There was one exception, Steve, which is that when people shopped when they were hungry, everything broke down. People just went and bought unhealthy food.
INSKEEP: (Laughter) Of course. You want to eat before you shop. But let me ask about this segmented cart, Shankar. Is this - as the research you often bring us so often is - creepy because people are being...
INSKEEP: Controlled without realizing they're being controlled?
VEDANTAM: I suppose that's the case, Steve, but this is part of a broad area of research which suggests that, in some ways, people actually have a choice. You're not actually telling people you have to buy the fruits and vegetables. You're just giving them a little nudge. Sometimes they follow it, sometimes they don't.
INSKEEP: Hey, that's NPR's science correspondent Shankar Vedantam who fills the social science box on MORNING EDITION from NPR News. You can follow him on Twitter, @hiddenbrain, and follow this program, @morningedition, @nprinskeep, @nprmontagne, and @nprgreene with an E. Transcript provided by NPR, Copyright NPR.