超市里暗藏的那些“潛規則”

Every time you enter the supermarket, you're being manipulated. By design, all of the basics you're just dropping by to pick up lie on the far side of a sea of temptation: the eggs, milk, and bread are blocked by fruit snacks, those fancy new chips, and a display of artisanal beef jerky. If that wasn’t enough, your kids are targets too: all the cereal at the eye level of a child sitting in a shopping cart is pasted with cartoon blandishments, the better to lure them in with.

But could we be manipulated for the better? The average food manufacturer has little reason to divert us from their high-fat, high-sugar, high-deliciousness products. Yet given that we are already being influenced, one can wonder whether stores might eventually see the benefit – perhaps administered through public health-related tax cuts – to making the produce section into a wonderland that has the kids screaming for kale.

Even within our current stores, it isn't difficult to nudge people in a better direction, at least in the short term. Esther Papies, a professor of social psychology at Utrecht University in the Netherlands, found that handing out recipe flyers at a store entrance that included words like "healthy" and "low-calorie" caused people who were overweight or dieting to subconsciously buy fewer snacks. They took a whopping 75% fewer snack items to the checkouts than those who received the control flier, which did not have the health-related terms on it. Seeing those words – being primed by them – activated people's existing goals and reminded them what they could do now to meet them, without the shoppers really taking notice, says Papies.

Other tricks have been proposed by Brian Wansink, a professor of consumer behaviour at Cornell who's well known for his research into the psychology of eating. Some of his latest work takes an earlier finding – that people increase their fruit and vegetable intake by 24% if they are told that half of their dinner plate should be reserved for these foods – and applies it to supermarket shopping. Wansink found that dividing a grocery cart in two, with half to be used only for fruits, vegetables, dairy, and meat, causes people to spend more than twice as much on fruits and vegetables than people without a partition – $3.65 versus $1.82 on fruits and $5.19 versus $2.17 on vegetables. The idea is that the partition implies the existence of a social norm that consumers try to meet.