Can behavioural science help us save the planet?

Take a look at this ad. It’s fairly typical of attempts to make people change their behaviour for the good of the planet. The aim is to shock people by the sheer scale of the problem. And it is pretty shocking — half of all food is going to waste. Shameful.

But if you’re anything like me, you’ll be thinking, “Well, I certainly don’t waste half of my food. So, I’m doing fine.”

Another reaction might easily be, “Well, if everyone else is wasting so much, I can’t make any impact by myself, so what’s the point?”

Either way, your behaviour is unlikely to change. And there’s academic evidence to suggest why such ads might backfire — because highlighting bad behaviours only makes them worse.

Leading by (bad) example

The classic study demonstrating what I call negative social proof comes from Robert Cialdini, a psychologist at Arizona State University and author of Influence: The Psychology of Persuasion.

In 2003, he carried out an experiment in Arizona’s Petrified Forest National Park. Petrified wood is a beautiful natural artefact, a coloured stone-like fossil that forms when minerals invade tree trunks. At the time, people were stealing over a tonne of it every month from the park.

For this study, Cialdini placed pieces of petrified wood at three separate spots close to footpaths and installed CCTV to monitor passers-by. On two of the three routes, the researchers placed notices to discourage stealing; the third was left with no sign, as a control. With no sign, 2.9% of marked pieces of wood were taken.

One sign stressed that stealing was damaging: “Please don’t remove the petrified wood from the Park, in order to preserve the natural state of the Petrified Forest.” This reduced the theft rate to 1.7%.

The negative social proof message read: “Many past visitors have removed petrified wood from the Park, changing the natural state of the Petrified Forest.” This had the opposite effect, increasing the thefts to 7.9%.

To create strong memories, use concrete languageAs Cialdini suspected, mentioning that theft was commonplace had reduced the perceived transgression of the crime, thus making it more popular.

So, telling us that half of UK food is wasted only portrays wastage as the norm and may inadvertently encourage it.

It’s not just sustainability messaging that gets it wrong. There are examples of the misuse of social proof in every walk of life.

What else can you do?

The lemon ad, and many more like it, may have a counterproductive effect. But that doesn’t mean there aren’t things you can do to boost sustainable behaviours.

It’s clear that people like to do what everyone else is doing — social proof has consistently been shown to be one of the most compelling drivers of behaviour. So the obvious answer is to make it clear that your desired behaviour, such as not wasting food, is commonplace. But what if it isn’t?

Thankfully, social proof is not limited to absolute claims (e.g. “most popular”). Research suggests that emphasising a behaviour is becoming more commonplace also taps into social proof, even if the behaviour is still reasonably rare.

It is up to marketers to make a sustainable world a realityEvidence comes from a 2017 study by Stanford University psychologists, Gregg Sparkman and Gregory Walton, who explored the impact of what they called dynamic norms, as well as static norms, in encouraging people to eat less meat.

They ran an experiment in a café that offered a mix of dishes, including vegetarian options. They asked the café to display one of two messages:

Static: “Recent research has shown that 30% of Americans make an effort to limit their meat consumption. That means that three in 10 people eat less meat than they otherwise would.”

Dynamic: “Recent research has shown that, in the last five years, 30% of Americans have now started to make an effort to limit their meat consumption. That means that, in recent years, three in 10 people have changed their behaviour and begun to eat less meat than they otherwise would.”

After tracking customer meal choices, the researchers found that those who read the dynamic statement were significantly more likely to order a meatless meal (34%) than those who saw the static norm statement (17%).

Easy does it

Using social proof can be highly effective at shifting people’s motivation. But changing a person’s motivation can still be really hard. Is there a better way to influence actions?

Yes, according to Nobel Laureate Daniel Kahneman. He said that the single biggest thing he had learned from all the studies he ran over the years is that the most effective way to change behaviour is to make it easier.

Because small, seemingly inconsequential barriers can have a disproportionate effect on behaviour.

So, make your desired behaviour really, really easy.

We don’t have to take Kahneman’s word for it. There’s a growing body of evidence to support the impact of ease on our actions.

For example, in 2011, Paul Rozin at the University of Pennsylvania and his colleagues explored the effects of ease on eating behaviour.

Using a university cafeteria as a test site, Rozin and his colleagues varied two factors for various healthy foods: the ease of access, by moving foods to make them easier or harder to reach; and ease of serving, using either a spoon or tongs to make them easier or harder to put on the plate.

The researchers monitored the consumption of healthy foods before and after they made these changes. Results showed that making healthy foods more difficult to reach/serve reduced consumption in the range of 8-16%.

If you’d asked the diners whether they thought little differences like reaching slightly further would impact their choices, they would have said no. But look at the results, tiny tweaks really do change decisions.

So, when you want to influence a sustainable behaviour, think carefully about any tiny blockers to this behaviour. Remove any piece of friction that you can, even if it seems inconsequential. Couple this tactic with effective use of social proof — and you should avoid looking like a lemon.

Richard Shotton is the founder of Astroten and author of The Illusion of Choice, a book about applying behavioural science to marketing.