Trash Talk: What’s the Psychology of Littering?

I’m one of those people who pick up trash from the sidewalks and gutters. Yeah – its gross. But I’m in good company. No less than former Governor and 1988 Democratic nominee for president Michael Dukakis is renowned for his trash picking acumen, as this recent Globe article reminds us. Comedian and author David Sedaris is such an active litter collector that he had a garbage truck named after him. For folks, like me, who also jog for exercise and who can’t help picking up the stray plastic bottle or aluminum can, there’s plogging: an exercise that combines jogging and litter picking.

trash from plogging

Plastic trash picked up on a recent run around Belmont. Also…a samara from a maple tree. 🙂

Alas, despite the efforts of us litter pickers, there is no shortage of work. In fact, once you “open your eyes” to litter – that is: once you allow yourself to notice it – you realize that it is everywhere. On an average run around town – maybe 3 to 5 miles – I typically return with two or three discarded items. If I picked up everything I saw, it would be an armful or more of trash. Clear plastic containers like bottled water and Gatorade or Starbucks and Dunkin’ Donuts takeout cups are by far the most common items. Plastic straw bans are catching on, and you find lots of plastic straws as well, often perched across the openings to sewer grates. Still: in my experience aluminim cans and glass bottles are far more rare? Why? You guessed it: that nickel deposit.

A 2014 referendum would have added bottled water and other “non carbonated” sports drinks to the list of the beverages covered by the state’s bottle bill. Items on the bottle bill get recycled at more than three times the rate as items that are not covered by a deposit (70% compared to around 20%). No surprise: stern opposition and an $8 million campaign by the American Beverage Association and local supermarket chains – a campaign filled with distortions – scared voters and doomed that referendum at the polls.

Needless to say: litter is a bigger problem than ever here in Belmont and elsewhere. And, while we can fret about the Great Pacific Garbage Patch, some of the most dire consequences are close to home. Rat infestations at Joey’s Park in recent years prompted the closing of the park on two occasions. Town officials responded by removing trash cans from the parks to cut down on litter. But as this article in the Citizen Herald notes, that experiment didn’t pan out: trash cans are returning to both Joeys Park and Town Field.

Trash Cans at Joeys Park

Trash piled up at Joey’s Park after trash cans were removed. (Photo courtesy of Paul Rickter.)

But I’ve never been in favor of throwing up my hands in despair. Nor do I think the “trash cans vs. no trash cans” debate really captures the complexity of the litter issue. The question we should be asking, I believe, are about the psychology of littering and how we can best stop the practice by anticipating what motivates people to litter in the first place.

It turns out there’s a fair amount of research that has been done on littering – some of it specifically focused on littering, and some of it that simply uses littering as a great example of group behavior.

Much of that research has discovered the same underlying phenomenon. No surprise: the harder you make it for people to do the right thing (throw your trash in a trash can) the less likely they are to do it.

More interesting, though, is that people’s inclination to litter is very dependent on their reading of social clues. If they perceive that littering is frowned upon, they will abstain from it. If, on the other hand, they get the cue that littering is acceptable, they will litter.

What sends the signal that littering is acceptable? That’s easy: the presence of litter. In other words, if people see evidence that others have littered, they will litter also – thereby increasing the amount of litter and strengthening the “go ahead and litter” signal to others.

That’s easy enough to understand. But what indicates disapproval of littering? First and foremost: the absence of litter – clean parks, clean streets and gutters. We all tend towards “normative behavior,” meaning we are less likely to litter if they perceive that they are in a place where others do not engage in that activity.

That’s an important distinction that matters for towns trying to figure out how to tackle littering. Robert Cialdini, a professor at University of Arizona, has done some of the most cited research on this question and has written about what he calls “environmental persuasion” – small ways to get people to abandon wasteful practices like using too many towels at a hotel. In a 2014 Atlantic article, he noted that, with littering, communities need to marginalize the behavior and communicate the notion that most people do not litter. Rather than complain about all the people who are littering, in other words, Cialdini says communities should emphasize how few people litter and the negative impact their actions have on the larger group.

“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.”

“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.’”