A Soda Bottle’s Shape Tricks You Into Buying It

Photo: David C. Humphreys/Getty Images

I was standing in the aisle of our nearby Target, lugging my one-month-old daughter in her portable car seat. It had taken me almost a month to get up the courage to venture to Target on my own with my newborn. What if she started screaming, spit up — or both? There I was, standing with the baby in one hand, trying to decide which diapers to purchase. I automatically reached for a small package of 24 diapers with my free hand, easily balancing my newborn and the nappies. 

Somewhere in the back of my mind, however, I realized that I probably needed a bigger package of diapers, unless I wanted to test my luck with another solo store run in a few days. But I had a bad feeling about the larger package. It wasn’t the price (the bigger pack was clearly more economical than the smaller pack) nor the look (the packaging was identical), but something pushed me away from the super-size. Only after I started doing research on how our bodies influence our preferences did I realize that it was probably the simple fact that I would have a hard time carrying my newborn and the bigger diaper pack that swayed my choice to buy less. 

Our motor systems unconsciously cue us in to the possible outcomes of our actions, even before we have completed them. In a study my Human Performance Lab recently conducted, we seated undergraduate volunteers at a small table where we had placed two different kitchen utensils: a wooden mixing spoon and rubber spatula. We were particularly careful about how we placed the objects. Sometimes, both objects were positioned so that the handle was closest to the volunteer and they were easy to pick up by the handle. Sometimes, the part used to mix or flip was facing the volunteer, who had to reach around and contort her wrist in an uncomfortable way in order to grab it by the handle. Keep in mind that we didn’t ask the volunteers to actually use the objects for cooking or mixing. Their only task was quite simple: to pick up the utensil they liked better. 

One of the real-world consequences of this human quirk is that subtle changes in the placement or packaging of products can have big effects on people’s desire to buy them. It is well known that the way products are organized in store aisles and whether they are at the entrance or the exit to the store can have a striking impact on what people buy. But less attention is focused on how our fluent interactions with a product might change, say, according to how easy it is to carry. Certainly companies like Procter & Gamble, which makes everything from hair care products to Tide, and beverage companies like Coca-Cola have tuned in to the idea that our bodies’ actions can influence our minds. How easy it is to grasp a product influences consumer choice. Just think about the evolution of product packaging. Most liquid detergents now come in bottles with handles. This is also true for large bottles of milk and Tropicana orange juice. Several years ago, the two-liter Coke bottle got a curvier look that facilitates picking up and pouring; coincidentally, sales rose over those of its closest rival, Pepsi. 

This is no accident. Packaging that affords easier carrying might subtly push people to purchase larger quantities of a product. In the wake of Coke’s sleek new bottle, PepsiCo decided to hire a chief design officer, Mauro Porcini, who was 3M’s first chief design officer. PepsiCo plans to invest $600 million in advertising to grow the market share of its leading brands, such as Pepsi, Gatorade, and Doritos. No doubt, some of that money is going to go into thinking about the ease and fluidity with which people handle the products. When something is easier to pick up, all else being equal, we like it more. Your purchasing decisions may be dictated by something as seemingly inconsequential as the shape of the package, without you even being fully aware of it. 


A Soda Bottle’s Shape Tricks You Into Buying It