Mind & Body

Why Most Grocery Shoppers Buy More Than They Mean To

You walk into the grocery store with a five-item list: milk, eggs, chicken breast, bread, tomatoes. You leave with 15 items, including the chocolate cookies that were too tempting to pass up and the trail mix you definitely didn't need. What happened? Turns out the grocery store is set up specifically to lure you into buying more than you meant to. In fact, one expert on the science of the supermarket says that for the average shopper, 60 percent of what's in their basket isn't what they intended to buy.

Supermarket Psych

A trip to the grocery store is never as simple as it seems. According to the Food Marketing Institute, grocery stores carry an average of 39,500 items, so they'll go to a lot of effort to make sure a lot of them end up in your cart.

Let's start with the layout. "There's a reason why produce and often the bakery are the first sections you hit," Paco Underhill, author of "Why We Buy: The Science of Shopping," told the Chicago Tribune. "First of all, the produce section tends to be lit theatrically, so that everything looks better in the store than it ever will when you get it home. Almost every supermarket knows that if they can get your saliva glands working, you will tend to buy more. So there's a reason why the bakery is up front, or the flowers are up front."

You might also notice that the most popular products are always in the middle of the aisle. That's to counteract what's known as the Boomerang Effect, which, as National Geographic explains, occurs when a shopper walks down an aisle to get what they want and leaves that aisle the way they came. Stocking popular items in the middle forces a shopper to pass the most items — and get tempted by the most items — in order to find what they're looking for.

Milk is usually is stored in the back of the store for the same reason. The more items you pass, the more likely you are to get distracted and pick up an extra few purchases. And kid-friendly snacks are stored lower down on the shelves, so toddlers will easily spot them.

All these distractions work. As Underhill told the Chicago Tribune, "One of the things that the Food Marketing Institute and the Point-of-Purchase Advertising Institute have told us is that roughly 60 percent or more of what we buy in the supermarket wasn't on our list. If I stop somebody on their way into a store and have them review for me what their mental list or written list is, and then I look in their basket as they walk out the door, roughly 60 percent of what's in that basket they didn't tell me about walking in."

This Is Your Brain on Shopping

It's not just the setup of the store that makes grocery shopping a psychological minefield. According to research out of Bangor University, which looked at brain scans of supermarket shoppers, customers start making emotional shopping decisions after only 23 minutes in the store. "Results also show that after 40 minutes — the time taken for a typical weekly shop — the brain gets tired and effectively shuts down, ceasing to form rational thoughts," according to a press release about the research.

As one of the researchers explained to BBC: "We know from previous research that the brain behaves illogically when faced with the sort of information overload that shoppers are faced with in a typical supermarket. Now we have a reliable and scientific way of validating this research and understanding exactly what is happening in the brain during the weekly shop."

The takeaway: Bring a list, stick to it, and make your shopping trip as speedy as possible.

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Learn more about these tricks in "Brandwashed: Tricks Companies Use to Manipulate Our Minds and Persuade Us to Buy" by Martin Lindstrom. The audiobook is free with an Audible trial. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Rachel Bertsche Levine April 11, 2017

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