When Clarence Saunders patented the “self-service” grocery store in 1916 and created the Piggly Wiggly, he was setting us on a path to the modern supermarket. In Saunders’s vision, shoppers could move around aisles and select their own purchases rather than depending on a shopkeeper to retrieve them. The next step was the expansion of such stores to offer a larger range of goods than the average shopper could carry in a basket. We needed carts (or buggies, or trolleys, the name varies depending on where you live—the wire basket on wheels), to move our selected products through the store and out to our cars.
With postwar population growth outside urban centers, carts became a staple of suburban life, both as part of our consumer practice and environmental clutter; they find their way into canals, storm drains, and vacant lots. If you were, like me, a suburban teen, you probably rode in one at some point or pushed someone else around the store or parking lot. They’re part of our everyday experience; everyone can relate to dealing with the ubiquitous wonky wheel or their tendency to run away from you on a slope.
They’ve also changed our shopping behavior.
Marketing scholars Udo Wagner, Claus Ebster, Ulrike Eske, and Wolfgang Weitzl used observations of shoppers with carts to analyze shopping practices, arguing that the cart itself drives some choices.
They looked particularly at how often people “parked” their carts, or left them to go and get something else from a shelf, suggesting that this happens more around particular products. This behavior could be taken into account when planning store layout.
“In general, most shoppers do not leave their shopping carts unattended when shopping for general groceries,” they write. “The parking of shopping carts…does, however, become considerably more frequent and longer when consumers shop for fruits & vegetables and meat & sausages in those departments.”
The reasons aren’t fully clear, but it could be because those are the areas that customers wish to spend more time examining products for freshness. The researchers also found that “parking” the cart was more associated with spontaneous purchases. We park our cart like we park our other vehicles, to return to later. We treat the supermarket like the streets.
Meanwhile, the wheeled cart itself, by taking the weight of our groceries, encourages us to buy more and assumes a particular model of shopping (arriving by car, shopping on a weekly or less frequent basis). This has shaped not only consumer behavior but that of manufacturers, leading them to producing larger packages that aren’t suitable or easy for someone to carry by hand. It’s a model of shopping that also assumes storage space in the home as well as refrigeration, allowing us to shop much less frequently than earlier generations.
According to Scientific American, the existence of carts also creates a natural experiment in human behavior, in terms of whether people return their carts after putting their groceries in their car. It’s a perfect experiment because there’s no penalty for failing to return a cart or reward for doing so. It’s entirely a free choice. (At least for most grocery stores in the US: at ALDI US, which originated in Germany, there’s a system of leaving a coin or token to unlock a cart; the deposit is returned when the cart is returned to the store. The deposit system is more common in European countries).
Do you return your cart, or do you just push it into the next parking space? The shopping cart choice reveals who you really are.