Shopping with the munchies can put a dent in your bank account and leave you with a pile of unwanted purchases. So suggests recent research showing that hunger not only drives people to acquire food, but also to buy totally unrelated non-food items.
“Conventional wisdom would say don't go grocery shopping when you're hungry,” says Alison Jing Xu at the University of Minnesota. “Now it seems it's probably better to feed yourself before any type of shopping, whether you're going on an actual shopping trip or shopping online. And if you're really hungry, you'd better think twice before purchasing any items at all or you might regret those purchases later.”
This warning is especially important, she notes, now that technology enables consumers to shop anytime from just about anywhere.
Hunger is a primal human urge that drives us to find, acquire and consume food to meet our caloric needs. Many previous studies have focused on the ways hunger impacts how people think about getting food. But in their study, published this week in the journal PNAS, Xu and her colleagues explored whether hunger can change people's thoughts, decisions and behaviors toward acquiring non-food items.
Xu and her team ran a series of five behavioral experiments that included a total of 379 people. In one experiment, volunteers were questioned at a cafe, ranked according to how hungry they felt, and then asked to comment on a number of food items, like sandwiches or cookies, as well as non-food items, like spa visits or iPad Minis.
Not surprisingly, hunger made people more likely to rate food items highly, while it had no impact on their probability of liking non-food items. However, when it came to their desire to actually acquire these items, hungry people wanted to get significantly more of both the food and the non-food items than their better-fed peers.
A later experiment invited a hungry group of people to the university, where half of the volunteers were treated to cake. All subjects were then shown some binder clips and asked how much they liked them and how many they would like to take with them for free. Hungry and non-hungry participants (self-reported on a scale of 1 to 10) roughly agreed on how much they liked the clips. But when it came time to actually take some, the hungry group snatched 70 percent more than their peers.
With this result in hand, Xu and her colleagues explored whether hunger drove people to acquire non-food items even when they had to pay for them. The researchers traveled to a large department store and scanned the receipts of 81 shoppers, who then self-reported their mood and how hungry they were. After for controlling for mood and length of time shopping, the results showed that hungry shoppers purchased more non-food products and spent up to 60 percent more than others.
The findings suggest that hunger creates an acquisitive mindset that encourages people to get more stuff in general—no matter if it is offered for free or carrying a price tag. “This domain-specific motivation, hunger, can spill over and influence behaviors in other domains that are irrelevant to the initial motivation,” Xu explains. “That happens because this strong initial motivation would activate these acquisitive behaviors, and they are applicable to non-food decisions as well.”
This phenomenon is likely to have its limits, Xu stresses. After all, when taken to extremes, hunger is about the drive to stay alive, and at that point it is likely to focus a person's attention entirely on getting food.
“We studied people who felt hungry but were still out shopping,” she says. “We didn't look at extreme situations, where people are really starving for a few days and have to really focus on food. When that's the case, they are obviously not going to be out shopping in a department store.”