You have a list. You have a strategy. And the goal of the grocery store is to make you deviate from this strategy so that you buy things you don’t really need. There are pitches to match every persona: flashy plastic toys hung in the canned food aisle to tempt the hands of toddlers; neon-colored drinks with lightning bolt symbols that promise to reshape middle-aged middle managers into Greek gods and goddesses; produce glistening with dew and right next to it the organic alternative that asks, Isn’t your family’s health worth another 34¢ per pound? Once you’ve run this gauntlet, you’re finally ready to congratulate yourself at the checkout stand. And self-congratulation is right there at eye and hand level in the form of candies and salacious magazines. You bought organic bananas and didn’t buy the baker’s dozen carton of glazed donuts—don’t you deserve a Milky Way?
Like the rides at Disneyland that spit you into shops that merchandise the ride’s characters, or a Vegas casino with inexpensive slots by the doors, the grocery store is a system designed to shake you upside down until every last bill and coin and plastic-mediated promise to pay has spilled from your body. How successful you are at remaining solvent in the face of this great shellacking depends on your brain.
Researchers can look inside your brain to see buying decisions being made in real time. There are two general structures at play: your amygdala and your prefrontal cortex. Your amygdala lusts after that Milky Way, and your prefrontal cortex wonders if it’s really a good idea. When researchers use fMRI to look at activation in these brain regions, the balance can help to predict whether you buy or abstain. The fascinating and potentially evil field of neuromarketing also looks at how products can be packaged and priced in ways that make you reach for your pocketbook. Really: if a product’s packaging promises something that speaks to your amygdala, you want it, and if the price is just low enough, your amygdala has the power it needs to overrun your prefrontal cortex. In lab studies (but not yet in wide use), marketing techniques that balance amygdala activation with prefrontal activation can help companies price their products to maximize profit without losing the sale.
This scale on which you weigh “want” and “should” in your brain is also the genius of the 1980s Miller Lite advertising slogan “Tastes great, less filling.” Your amygdala anticipates the taste, and your prefrontal cortex loves the idea that this lite beer is a healthy option.
But this want/should scale is only the backdrop against which you make buying decisions, after which everything from mood to hunger to personality to money to stress presses down with its thumb on one side of the scale or the other. For example, if you have less time available to shop, fewer items from your list and more unplanned items are likely to end up in your basket. That makes sense: decisions made while stressed for time aren’t likely to be as thoughtful and measured as decisions made with your rational brain more firmly in the driver’s seat. But check out this unfortunate corollary, which works through a similar channel: people who have less money may be more prone to making impulsive purchases in the checkout line. It comes down to something social psychologist Roy Baumeister calls ego depletion (also known as decision fatigue). It seems that after making many difficult decisions we break down and take the easy choice later on. For example, when researchers have offered snack choices after laboratory tests, they see that when a test is difficult, test takers choose donuts over fruit—their ego is so depleted from the test, they fail to fight off temptations they might refuse in a more ego-full state. (You can only fight snack food for so long!)
Grocery store delicacies aren’t the only things that create ego depletion. For example, Princeton economist Dean Spears offered villagers in India the option to buy bars of soap, deeply discounted but still a stretch for many. Afterward, Spears asked villagers to hold their hands in a bucket of ice water—a task that is a common proxy for willpower. With their ego depleted by the difficult soap-buying decision, the villagers held their hands in the ice water for a shorter time. Here’s the fascinating part: the reduction in willpower as measured by the ice bucket task was exactly proportionate to villagers’ income. When the decision to buy soap was more stressful, weighed perhaps against the decision to buy other necessities, it caused more ego depletion and lowered villagers’ willpower for subsequent tasks. The less money a person had, the less willpower they had after making financial decisions.
Let’s take it back to the grocery store. Food shopping in general requires decisions, but food shopping on a budget requires difficult decisions. Now imagine two very different shoppers as they reach the cash register: one has spent the shopping experience moving from one fairly easy decision to the next and knows that his or her debit card is going to work on the first try, while the second shopper has just spent forty-five minutes weighing the need for food items against the need for car repairs and is trying to keep in mind the sequence of credit cards that might work. And there’s a Milky Way bar, displayed so that both shoppers can’t help but feel the temptation. Keeping in mind ego depletion and the want/should teeter-totter in your brain, who do you think is going to throw the candy bar on the checkout counter?
You know about music and lighting design, but a new field of sneaky marketing deals with a store’s smell-scape. For example, when researchers odorized areas of a casino for a weekend, slot machine use went up 45 percent compared to non-odorized areas. And a fascinating study in Marketing Review shows that store brands can hijack the goodwill of scents provided by premium brands—smelling a posh hand cream makes you evaluate a knockoff brand more favorably. Some department stores distribute scents through the air-conditioning systems, and others use scent stations to customize the scents of different departments. Next time you’re shopping, in addition to being aware of the music and intentionally placed impulse buys, take a whiff: do you think that smell is accidental?