How does one get clients to buy, citizens to vote, love interests to swipe right, or kids to do their homework? Professionally or privately, we all try every day to change people’s behaviour. And it’s an understatement to say we don’t always succeed.
Even provided with good reasons, strong arguments and seductive incentives people often fail to follow good advice or simple instructions. Science shows that in a whopping 78% of cases, we even fail to do what we ourselves have resolved to do. Interestingly though, in some cases, behaviour seems to change quite easily.
Often it’s little, everyday phenomena that succeed where rules, regulations and campaigns fail. This happens more frequently than you might expect.
And when it does, it’s called the Housefly Effect. The effect is named after the world’s most famous fly, whose natural habitat is Amsterdam Schiphol Airport. Exasperated at male travellers leaving the bathroom floors in a sorry state, the staff painted little houseflies in the urinals and promptly saved a fortune in cleaning costs.
It became a staple example of a “nudge”: something small that effectively changes behaviour for no rational reason. The famous fly first appeared in the airport in the early 1990s, but the idea wasn’t altogether new. In Stratford-upon-Avon, you can admire urinals with bees painted onto them dating back to around 1880, exemplifying typical British humour, as the Latin for bee, apis, sounds rather like what you’d use the urinal for.
One Housefly Effect has to do with placebos – a phenomenon not limited to medicine. You may never have heard of placebo buttons, but chances are you’ve pushed quite a few – and were happy you did.Workplace air conditioning systems sometimes employ fake buttons to create a false sense of control over the working environment.
And what about the “close door” button in the lift: does it really close the door? Or would it have closed anyway?
Urinal etched with housefly to help men aim straight (Image: Getty Images)
What about pedestrian crossings? The city of New York, for example, has 3,250 buttons on lights at pedestrian crossings – 2,500 of which do absolutely nothing. At least from a technical point of view.
What they do achieve is to give people the feeling that they have some influence on their waiting time at the stop light – making them less likely to recklessly throw themselves under a taxi. Because that’s the remarkable thing about this category of housefly effects: placebos don’t do anything, but they do work.
Another category of Housefly effects has to do with the way a choice is offered to people. Take for instance the technique known as choice substitution.
Someone in the UK designed a clever ashtray that asked: “Who is the best [football] player in the world?” People voted by dropping their cigarette butt into a bin with the name Ronaldo on it or into one labelled Messi.
Tim den Heijer is the co-author of The Housefly Effect (Image: Anne van Gelder)
Of course, the underlying question was: are you going to drop your fag end on the ground or will you dispose of it responsibly? Because it wasn’t made explicit, many more people chose the desirable option.
People tend to choose from the options presented to them, without asking if there are better options. Parents may use this on toddlers and substitute: “Will you put on your shoes?” with ‘‘Will you put on your green OR your red shoes?” Often, the Housefly Effect arises from our nature as social animals.
For instance, the mere suggestion that we’re being watched puts us on our best behaviour. It’s something religious leaders drew on long before it became the subject of systematic analysis by scientists: the higher power sees everything! The public sector isn’t averse to this tactic either. British citizens who refused to pay speeding fines did cough up when the penalty notice included photographic evidence of the traffic offence.
Also in the UK, in the south London borough of Woolwich, vandalism dropped by some 24% after children’s faces were painted onto shop front roller shutters. Eyes and faces hold a special place in our brains. Have you ever spotted a face in a car, the clouds or an electrical socket? It’s called pareidolia.
Eva Van Broek is co-author of The Housefly Effect (Image: Anne van Gelder)
Part of your brain is constantly on the lookout for faces. Supermarkets are infested with metaphorical houseflies!
Retailers know you walk faster as you approach the till. Behind the scenes it’s known as the “checkout magnet”. Shops have been known to try to slow down the trolley with grooved tiles, but in most cases the increased pace is desirable.
The quicker you decide, the less time there is for you to suppress your impulses, which is why you’re willing to pay more for a chocolate bar off the shelf at the till than for the same bar in a pack of five from the confectionary aisle.
Those impulses at the end of a shopping trip also dovetail with another scientifically disputed but very recognisable phenomenon: ego depletion, the hypothesis that after resisting a great deal of temptation (turning down a lot of drinks) you kind of run out of willpower (and go crazy with the canapés).
Perhaps your prefrontal lobe has blown its share of your brain’s energy budget.
The UK recently banned unhealthy products in “impulse buy spots”: only healthier products are now permitted near the exit and at the ends of aisles, which are particularly desirable positions for manufacturers. The housefly effect also works through influencing who or what receives our precious, limited attention. Does the name Party Cannon ring a bell?
There’s every chance it does, as the British death metal band has gone viral no fewer than three times. With their deafening music? Their doom-laden lyrics? No, with their logo. In their scene, the visuals are all pretty similar: horror-style, jagged black-and-white letters, like ominous cracks in stone.
Nearly all anyway, as Party Cannon have bucked the trend and have opted for a cheerful, multi-coloured balloon-like font that looks more at home in a toyshop.
It makes them stand out from other bands on festival posters. It’s one hell of a housefly, that typeface. The headbangers managed to become the talk of the town without changing a single note of their music. It wasn’t the colourful logo in and of itself; if it adorned children’s toys, nobody would bat an eyelid.
The thing itself isn’t attention-grabbing, but the contrast with its surroundings is. So in business, blending in is more risky than standing out!
Cigarette butt box making the act of not littering a choice between two questions (Image: Getty Images)
Of course, an upstanding politician should want nothing to do with this type of hidden influence… or should they? Ignoring the insights of behavioural science can have huge repercussions in the political arena.
You have an immediate lead over your opponent when they adopt your framing and explain at length why you are wrong to speak of a “ticking time bomb” or a “pernicious plague”. The pro- camp made brazen use of this when it sent a big bus around the country with the UK’s weekly contribution to Europe printed on its side.
The figure was untrue, because it was far too high. So obviously the Remainers sought to correct this in the media. They’d caught the Brexiteers lying! It wasn’t £350million, but “only” £248million! And soon the debate in the media and among the public moved away from all the positive reasons for staying in the EU, such as peace, the economy, travel and study, and on to the amount of money that went into European coffers. That was precisely what the Leavers were after. The frame as a political mousetrap.
The Housefly Effect is a fascinating examination of so-called ‘nudge theory’ (Image: Bedford Square)
The Housefly Effect isn’t limited to tacky casinos and discount stores. In fact, companies use this effect very effectively to heighten a sense of luxury. The remote control of an expensive audio system feels a little heavier. Now you might think that’s because of the quality of the components, but no, it simply contains some extra weight so it feels better.
Likewise, car manufacturers can tell you all there is to know about the sound of closing doors. You don’t want it to be plasticky, but heavy and solid, yet not too clunky either.
Websites that scan for information or offers make you look unnecessarily long at a progress bar, so you feel their processors are hard at work to give you value for money. The linen napkin in business class, the extra fancy transparent face masks worn by waiting staff at Michelin-star restaurants – all houseflies in expensive clobber. A phenomenon that often influences behaviour plays a part in this: scarcity.
Not everything that confers status is scarce, but scarcity can lend status to just about anything. Back in 16th-century England, pineapples were extremely rare and therefore a status symbol. Those who weren’t in a position to buy their own could hire one – not for consumption of course, but for display at the dinner table.
This is why sculptures and other representations still adorn the façades of British stately homes, proving that houseflies truly are everywhere.
The Housefly Effect by Eva van den Broek & Tim den Heijer (Bedford Square, £20) is out now. Visit or call Express Bookshop on 020 3176 3832. Free UK P&P on orders over £25