Psychologists have found a simple trick to reduce meat consumption in restaurants. Tell a customer that other people are increasingly choosing the menu's meatless options, and the customer becomes more likely to order a vegetarian meal.
It's a simple but effective intervention that relies on peer pressure and social influence to convince people to rethink their longstanding habits, says Gregg Sparkman, a Ph.D. student in psychology at Stanford University who led the experiment. Essentially, Sparkman's findings show that you can change a person's behavior by highlighting other people's success in changing their behaviors. In another forthcoming study, currently under peer review, Sparkman argues that the same method could be used to help people stop smoking, quit sugary drinks, and even to identify as feminist.
"When people see others changing, they envision that, in the future, norms might be even more different—that the trend is probably going to continue," Sparkman says. For the experiment, he persuaded restaurant-goers to imagine a world where people eat less meat, nudging them to change their own habits. "They're reacting to their anticipated view of the world. We call that 'pre-conformity': essentially, people conforming to how they envision the future will be."
Convincing people to change their deeply ingrained habits is difficult, and this intransigence has been a persistent problem when it comes to tackling climate change. According to a recent paper in the journal Science, "As the decades since the 1970s have revealed, merely educating people about what actions they can take does not dramatically shift behavior; nor does inspiring fear or guilt." As psychologist Elise Amel and her co-authors point out in the same article, while nearly half of Americans are "concerned" or "alarmed" about global warming, many still routinely fly, drive alone, and keep their homes at a constant 72 degrees Fahrenheit—all environmentally damaging behaviors that conservatives love to cite when they attempt to discredit climate change activists by pointing to behavior they find hypocritical.
There are various reasons why changing behavior is so challenging. One obstacle is the difficulty of prioritizing the long-term benefit to future generations over short-term personal convenience. In addition, Amel et al. point out, adopting sustainable behaviors that we think will be unusual to society at large can provoke fears of disapproval or rejection. While a sense of urgency is important, the authors write, individuals also need to have confidence that solutions are possible before they are inspired to act, or else they risk being paralyzed by despair.
A common method that psychologists use to subtly convince people to change behaviors is presenting "static norms": telling them that most people are already behaving in a certain way, a strategy that taps into the brain's deep-rooted desire to adhere to implicit societal standards.
But this method is unlikely to work when it comes to behaviors that contribute to climate change, since many of those behaviors—driving frequently, eating meat, flying—are an accepted part of everyday life. Yet while it's still normal to order a burger without a second thought, more and more people are questioning and abandoning such behavior; in a 2016 poll, 32 percent of respondents said they ate less meat than they did three years before. Sparkman wondered whether focusing on the changing nature of the trend—a "dynamic norm"—would have the same psychological impact on the brain as highlighting a current norm.
From Theory to Practice
Sparkman's experiment began as a more theoretical intervention, where the researchers gave people waiting in line for lunch a $5 voucher in return for filling out a survey about their eating habits. Some of these surveys told the participants that Americans were starting to consume less meat. In tracking their subsequent orders, the researchers found that this subset of the group was more likely to order a vegetarian meal than those who hadn't received this information.
"When something is already done by the majority of people, we give it the benefit of the doubt in a lot of ways. We think it must be effective, it must be enjoyable, people will like us if we do it. Turns out people do this for trends too," Sparkman says. "When we start asking ourselves why people are making this change, we start posing different answers to it: Maybe they do it because it's good for their health, or maybe because they're worried about the environmental impact of what they eat. You're essentially generating arguments why you might also want to do it yourself."
While the psychological concept proved a success, they knew the idea would remain useless without a way to replicate it across a large number of restaurants. So they came up with a more scalable but more subtle intervention. Earlier this year, they edited the menu at a burger restaurant at Stanford University called The Axe & Palm to include a small, unobtrusive message: "Our Meatless Burgers Are on the Rise." Tacked onto the card machine was another note: "We've noticed customers are starting to choose more meatless dishes."
These simple additions offered no moralizing, made no demands of the customer, and made no changes to the menu—and they worked. The team's unpublished results show that the intervention increased the proportion of meatless dishes sold by 1.7 percent. In other words, over the course of 17 days, this psychological trick persuaded over 180 people to switch to a vegetarian option. That increase might seem modest, but Sparkman says it's statistically significant, and that it’s worth bearing in mind that this is a burger restaurant, where people go expecting to eat meat. Plus, there were no guarantees that people would even read the team's posted signs.
"Even if the effects are small, we've come up with a way to make something highly scalable. Any restaurant could do this with relative ease. If it became something that the industry took on as a standard, then you could have a huge amount of change," Sparkman says.
That's exactly what the team plans to do next, as they move to roll out a similar experiment across a medium-sized chain of Middle Eastern restaurants in the American Southeast, before looking to engage larger companies—say, the Cheesecake Factory—within the year.
The research also contains a hopeful message for those who have felt the futility of attempting to bring about climate action: Small changes in individual behavior can sometimes bring about a revolution. Throughout history, large pivots have often been instigated by a small number of pioneers, Sparkman says. Understanding how this process works could be vital in helping mitigate the emissions that are causing climate change.
"People are already essentially informed, a lot of people are politically not opposed to [climate action], a lot can financially afford it; so the question is, what's holding them back?" Sparkman says. "It could be that other [people's] inaction is pretty debilitating. Maybe when you see information about others mobilizing and starting to make a change, perhaps there's something about it that can be contagious. Our research suggests that can be the case."
New Landscapes is a regular series investigating how environmental policies are affecting communities across America.