Our top 10 nudges: Behavioural Science in everyday advertising

Behavioural science and advertising are a love-hate relationship. Ad agencies thrive on creativity and often feel that applying scientific rigour could constrain their ideas. Scientists, in turn, find the large-scale experiments marketing offers intriguing but are wary of their research being misused.

However, both fields have something fundamental in common – they aim to influence human behaviour. Like most of us, in fact – because whether it's persuading people to buy, donate, or even getting kids to finish their meals, we're all trying to shape and change others' actions in some way.

This realisation struck us – Eva, a behavioural economist, and Tim, a creative strategist – when we teamed up to write The Housefly Effect. In the book, we explore how everyday phenomena, both intentional and unintentional, impact our decisions. We call these nudges 'houseflies,' a nod to the famous fly in the urinal – a tiny cue that triggered big behaviour changes.

Here, we share some of our favourite examples of behavioural science in action.

1. Domino's: 'Man Hungry Ding Dong Pizza'

It's a myth that we only use part of our brains. In reality, we use all of it, all the time. However, a key function of the brain is managing its resources, ensuring we don't expend more mental energy than necessary. When making quick decisions, our brains rely on mental shortcuts, also known as heuristics. This is where five-word slogan used by Domino's in the Netherlands  – Man Hungry Ding Dong Pizza – shines.

The simplicity of this phrase reduces cognitive load and triggers an automatic response. The brain doesn't need to process complex information or weigh different choices – it's a direct cue that makes it easy for someone to say, "I'm hungry, I'll order pizza." Domino's has built an entire business model around minimising mental friction, showing that simplicity can lead to action.

2. Specsavers: 'Should've Gone to Specsavers'

Most of us are familiar with Specsavers' long-running slogan, which is deeply ingrained in popular culture. While the humour behind it certainly plays a role in its longevity, the real genius lies in its use of behavioural science – specifically, the concept of anticipated regret.

When people are making decisions, especially about something as personal and long-lasting as glasses, they want to avoid regretting their choice later. The slogan nudges potential customers to think, What if I don't go to Specsavers? It taps into our natural fear of making decisions we'll regret, making the thought of missing out on Specsavers' services more uncomfortable than the decision to visit.

3. Swapfiets: The Iconic Blue Tyre

Social proof is one of the most potent tools in behavioural science. It's the idea that people look to the actions of others when making their own decisions. Swapfiets, a Dutch bicycle leasing company, used this concept brilliantly with its distinctive blue front tyre.

In the Netherlands, where nearly everyone owns a bike, the challenge wasn't selling the idea of cycling but making bike leasing seem as normal as buying. The blue tyre made Swapfiets bikes immediately recognisable, and the more people saw them, the more they assumed that leasing a bike must be popular. By leveraging the concept of social proof, Swapfiets encouraged others to follow the herd onto the bike lane, contributing to the success of their bike leasing model.

4. Durex: 'Buggy'

This clever Durex ad compared the cost of their condoms to the much higher cost of raising a child. It is a brilliant example of anchoring, one of the most well-known cognitive biases. Anchoring occurs when people rely too heavily on the first piece of information they receive when making decisions.

By juxtaposing the relatively low price of condoms against the much higher financial burden of parenthood, Durex reframed the context in which their product was considered. People no longer saw their condoms as expensive – they saw them as a bargain compared to the alternative.

5. The '3D' Zebra Crossing in Iceland

Driving is one of the most automatic behaviours many of us engage in. Our minds can be on autopilot, completing the route while our attention drifts to other thoughts. This is why traditional road safety campaigns, which appeal to conscious decision-making, often fail to change driver behaviour.

The '3D' zebra crossing in Iceland tackled the problem differently. It created an optical illusion that made the crossing appear to rise from the ground. The visual effect prompted drivers to slow down instinctively, bypassing the need for conscious engagement. This innovative nudge altered behaviour by subtly changing the environment, tapping into unconscious processes rather than asking for conscious decision-making.

6. Burger King Austria: 'Normal Oder Mit Fleisch?'

Plant-based diets are growing in popularity, but persuading meat-eaters to switch to vegetarian options can be a tough sell. Burger King Austria found a clever way around this by simply flipping the default choice. Instead of asking customers if they wanted a veggie option, they made plant-based the default and asked, "Normal oder mit Fleisch?" (Normal or with meat?).

This small change leaned on a key behavioural insight – people are much more likely to stick with the default option, even when it comes to important decisions. The nudge was subtle, but it sent a strong message: plant-based is the new normal, while meat is the add-on. This approach worked so well that it won a prestigious effectiveness award.

7. Schiphol Airport: The Fly in the Urinal

How do you improve cleanliness in public restrooms, especially in busy places like airports? Schiphol Airport in Amsterdam found an ingenious solution: a painted fly in the urinals. This tiny, simple nudge encouraged men to aim at the fly, significantly reducing splashback.

What makes this nudge so effective is that it doesn't rely on explicit instructions or incentives. The fly taps into an instinctive desire to aim, and the results speak for themselves. It's a prime example of how small environmental changes can lead to meaningful behaviour shifts, making it the epitome of a nudge.

8. This Is The Rubbish Dropped Since Monday – Let's Keep It Clean Campaign

Ouch. This is a case where behavioural science could have helped avoid a notorious misstep. The campaign, intended to reduce littering, showed the amount of rubbish dropped around a bus stop since Monday, hoping to shame people into keeping the area clean. However, from a behavioural science perspective, this approach backfired. 

As we saw with Swapfiets, when people see evidence of widespread behaviour, it triggers social proof – meaning they're more likely to follow suit. The unintended message here was: Everyone else is littering, so why shouldn't I? Instead of reducing rubbish, such a campaign may well make the problem worse, encouraging people to think their small contribution wouldn't matter amidst the mess.

9. Van Moof Bicycle Packaging: Reducing Shipping Damage

Van Moof, a Dutch company selling high-end bicycles, had a problem: too many of their bikes were arriving damaged due to rough handling during shipping. Traditional methods like 'FRAGILE!' stickers weren't working, so they took a more creative approach. They redesigned their packaging to look like it contained a flat-screen television instead of a bicycle.

This clever tweak tapped into people's unconscious associations with expensive electronics, prompting handlers to treat the boxes more carefully. The result? A 70 per cent reduction in damaged goods. This is a great example of how a simple change in perception can lead to real-world improvements.

10. IKEA: Exit Through The Hot Dog Stand

Why does IKEA, a furniture store, sell hot dogs at the exit? It might seem out of place, but this decision is rooted in a behavioural insight known as the peak-end rule. This rule states that people remember an experience based on its most intense moment and its ending.

IKEA realised that many customers left their stores feeling tired and frustrated after navigating the self-service stockroom and checkout. By offering an affordable and satisfying snack at the exit, IKEA ensures that customers leave on a positive note, improving their overall perception of the shopping experience. The hot dog isn't just a sausage on a bun – it's a carefully crafted nudge designed to leave customers with a pleasant memory of their visit.

Wait – will this still work now that we know?

By now, you may be alerted that companies and governments subtly steer your behaviour through tiny cues like flies and choice architecture. Wouldn't it be better to just give people the information and let them decide for themselves? When you come to think of it, there's no such thing as a neutral message. Every element of communication, from the order in which products are presented to the framing of choices, influences our decisions.

The Housefly Effect by Eva van den Broek and Tim den Heijer is published on 21 November 2024 by Bedford Square Publishing.