Littering and Following the Crowd

Why it's so tempting to throw trash on the ground, and how environmentalists are using psychology to change that

Vivian Wagner

Loretta Brown walked along Bishop’s Beach near Homer, Alaska, looking for plastic bottles, Styrofoam cups, beer cans, cigarette butts, and old fishing nets.

“You tend to find things among the driftwood, since the same tide that washes up the driftwood washes up the trash,” she said, stooping to pick up a plastic water bottle. “It’s kind of like an Easter egg hunt.”

Brown is a marine debris education and outreach specialist with the Center for Alaskan Coastal Studies, a nonprofit organization based in Homer that educates the public about coastal issues and offers eco-tours of the region. She also has a keen, experienced eye for litter.

“We’re likely to find some up here among the grasses,” she said, homing in on small pieces of Styrofoam nestled in clumps of grass among the basalt rocks and clam shells along the beach. “The birds will eat these.”

With all of the work she does picking up litter and educating people about the long-term environmental damage it does, Brown has developed some theories about what makes people throw out their trash, and how to get them to stop.

“It probably goes to our roots as a species,” she said. “We’ve always had refuse of some kind. In the beginning, it didn’t matter if you threw things on the ground, because it was biodegradable and would rot. It wasn’t a problem until plastic was invented.”

Education, she thinks, is the way to change the culture of littering.

“The best way for people to become engaged and change their behaviors is not just to inform them of the problem, but to have them actively experience the problem,” she said. “It’s about having the conversation—that really helps. It’s a behavioral change.”

Despite Alaska’s strict anti-littering laws, the state has a serious problem with marine debris because of ocean currents that bring trash from around the world to its shores, according to Julie Decker, director of the Anchorage Museum. In an exhibit called Gyre, the museum puts this trash on display, with artworks that incorporate and call attention to plastic trash collected from beaches worldwide.

The exhibit places litter under museum lights so that people will look at it, talk about it, think about where it came from, and ultimately change their behavior.

“In one moment you understand it,” she said.  “You see yourself in the problem. You see your own products. You see your own beaches. I wasn’t sure what kind of response we’d get, but watching children go through has been one of the most powerful experiences I’ve had. They leave talking about behavior, talking about what they’re going to do.”

One of the exhibit’s goals, according to Decker, is to start a conversation about why people litter in the first place.

“People want to make it invisible to themselves, to get rid of the trash and the smell,” Decker said. “Most people litter when they’re not being watched.”

Brown’s and Decker’s hunches about why people litter and what it will take to change their behavior have a basis in social science research, such as that done by Robert Cialdini, emeritus professor of psychology and marketing at Arizona State University and author of Influence: The Psychology of Persuasion.

“One of the things that’s fundamental to human nature is that we imitate the actions of those around us,” said Cialdini, who has conducted a number of landmark studies in littering and litter prevention—all of them pointing to the fact that people are likely to do what they think is expected of them. It’s about norms and expectations, he says: Change these, and you’ll change people's behavior.

Loretta Brown picks up litter on Bishop's Beach near Homer, Alaska. (Vivian Wagner)

“It’s the idea that look, no one is littering here, so it must not be a legitimate thing to do,” Cialdini said. “We take our cues about what to do in a particular setting by what people are doing there already.”

Some of Cialdini’s litter studies have taken place in parking lots and parking garages, with flyers placed under the windshield wipers of random cars. Unsuspecting subjects return to their cars and researchers observe them, to see what they do with the flyers. Will they throw them on the ground? In study after study, it turns out that cues in their environment are a strong determining factor in what actions people take.

“It depends on what you see immediately before you get to your car,” Cialdini said. “If you see a environment that is highly littered, you litter. If there is not litter, you are significantly less likely to litter.”

But if there is just one piece of litter in an otherwise litter-free environment, subjects are even less likely to throw their trash on the ground.

“If there is one piece, you are least likely to litter,” Cialdini said. “If you see one piece, it reminds you that most people are not littering here. It calls attention to the fact that the majority of people are not littering.”

Cialdini’s research echoes the “broken windows theory,” first introduced in 1982 by social scientists James Q. Wilson and George L. Kelling. This theory holds that people are more likely to break windows, write graffiti, or deface an environment if it’s already been defaced. One broken window, in other words, leads to more broken windows. And likewise, a littered stretch of beach or highway leads to more littering.

In Cialdini’s research, what people see being done around them also affects their actions. Thus, if they see someone throwing a flyer on the ground nearby, they are more likely to throw their own down. And if they see someone reacting disapprovingly to littering, they are less likely to litter themselves.

“The most dramatic results we’ve gotten are from situations that show people disapproving of littering,” Cialdini said. “One study took place in a library parking lot. People left the library, and there was a piece of paper on their windshield. The thing that most affected people was when they saw someone nearby reaching down and picking up a piece of litter with a disapproving look. When they got to their own cars, not one person littered. If they didn’t see anyone picking up litter, 33 percent littered. We went from a third of the subjects littering to zero, when they saw an example of someone like them who picked up litter and showed disapproval.”

Cialdini argues that the results of his studies demonstrate that people are sensitive to what they see as normal behavior, and they’ll change their behavior to adapt to what they see being done around them.

“It all comes down to norms, and you get those cues from the environment,” he said. “People litter for reasons of convenience. They don’t want this thing. The crucial question is why don’t they litter, since the easy thing is to litter. Why would people hold onto a piece of trash? Their attitudes toward the environment make a difference, but what they perceive as the norm is key.”

He argues that the classic 1971 Keep America Beautiful television commercial showing a Native American man (who was later revealed to be actually Italian) crying amidst a polluted environment, therefore, was not as effective as it could have been, since it depicted an already trashed landscape. A more effective campaign, he says, would create and enforce a positive norm.

“You need to indicate disapproval of littering in all of your signage, not by saying that there are so many people littering, but by saying that if one person litters, it destroys the beauty of the park,” Cialdini said. “Instead of normalizing littering, you need to marginalize it with your message.”

Cialdini has recently expanded his research into other areas of environmental persuasion, such as convincing people to reuse hotel towels. He has worked with hotel chains to design signage with messages like “the majority of our guests reuse their towels”—thus creating a norm that people are likely to follow.

“You ask, ‘What are people like me doing?’” Cialdini said. “People decide what to do based on what people like them have been doing.  If you say, ‘The majority of our guests have reused their towels,’ you get more compliance than if you say, ‘Do it for the environment.’”

Meanwhile, people on the front lines of the litter war are struggling to come up with messages that work. Joel Hunt, a public information officer with the Ohio Department of Transportation (ODOT), admits that despite public relations campaigns, littering in his state remains at an all-time high. According to Hunt, more than 400,000 bags of litter being picked up along Ohio’s roadways each year.

ODOT, like other state transportation agencies, is tasked with cleaning up its roadways and partnering with other agencies to educate the public about the problems with littering. A recent public information campaign called “Untrash Ohio,” sponsored by Keep Ohio Beautiful, for instance, featured billboards with images like that of someone fishing and reeling in a plastic bottle.  And ODOT’s adopt-a-highway program—which gives individuals and organizations the opportunity to adopt a section of highway to keep it clean—seeks to create clean roadways so that, ideally, people will be less likely to litter on them.

Hunt says that his agency continues to try to combat the problem of littering, and he hopes that eventually its efforts will pay off.

“It’s a $4 million preventable problem,” said Hunt. “That money could be used to purchase 28 new snow plow trucks or to repave a 40-mile two-lane road every year.”

Instead, Ohio spends that money—and much time and effort—on collecting all the bottles, cans, and other pieces of trash that inevitably end up along its roadways. It’s a seemingly endless cycle, but litter research suggests that without these clean-up efforts, the problem would get even worse.