The English language is full of metaphors linking moral purity to both physical cleanliness and brightness. We speak of “clean consciences”, “pure thoughts” and “dirty thieves”. We’re suspicious of “shady behaviour” and we use light and darkness to symbolise good and evil. But there is more to these metaphors than we might imagine. The mere scent of a clean-smelling room can take people down a virtuous road, compelling them to choose generosity over greed and charity over apathy. Meanwhile, the darkness of a dimmed room or a pair of sunglasses can compel people towards selfishness and cheating.
These new results are the latest from psychologist Chen-Bo Zhong. Back in 2006, he showed that people who brought back memories of past wrong-doings were more likely to think of words related to cleaning, or to physically crave cleaning products. He called this the “Lady Macbeth effect”. Subsequently, another group found that it works the other way too. People judge moral transgressions more leniently if they had previously washed their hands or if they had been primed with words related to cleanliness, like ‘pure’ or ‘immaculate’.
Now, Zhong, together with Katie Liljenquist and Adam Galinsky, have expanded on these studies by showing that clean smells can make people behave more virtuously. They ushered 28 volunteers into a room that was either unscented or that had been lightly sprayed with a citrus air freshener. In either case, they had to play a trust game, where a “sender” has a pot of money and chooses how much they want to invest with a “receiver”. The investment is tripled and the receiver decides how much to give back.
The volunteers were all told that they had been randomly chosen as receivers. Their anonymous partner had invested their entire $4 pot with them, which had been tripled to $12. Their job was to decide how much to give back. On average, they returned a measly $2.81in the unscented rooms but a more equitable $5.33 in the scented ones. The single spray of citrus nearly doubled their tendency to reciprocate.
In a second experiment, the trio again ushered 99 students into either a scented or unscented room. They were given a pack of miscellaneous tasks, including a flyer requesting volunteers for a charity called Habitat for Humanity. Those in the citrus-scented rooms were more likely to be interested in volunteering, and almost four times more willing to donate money to the cause.
In a world where the temptation to lie, deceive and cheat is both strong and profitable, what compels some people to choose the straight and narrow path? According to a new brain-scanning study, honest moral decisions depend more on the absence of temptation in the first place than on people wilfully resisting these lures.
Joshua Greene and Joseph Paxton and Harvard University came to this conclusion by using a technique called functional magnetic resonance imaging (fMRI) to study the brain activity of people who were given a chance to lie. The volunteers were trying to predict the outcomes of coin-flips for money and they could walk away with more cash by lying about their accuracy.
The task allowed Greene and Paxton to test two competing (and wonderfully named) explanations for honest behaviour. The first -the “Will” hypothesis – suggests that we behave morally by exerting control over the desire to cheat. The second – the “Grace” hypothesis – says that honesty is more a passive process than an active one, fuelled by an absence of temptation rather than the presence of willpower. It follows on from a growing body of psychological studies, which suggest that much of our behaviour is governed by unconscious, automatic processes.
Many studies (and several awful popular science articles) have tried to place brain-scanning technology in the role of fancy lie detectors but in almost all of these cases, people are told to lie rather than doing so spontaneously. Greene and Paxton were much more interested in what happens in a person’s brain when they make the choice to lie.
They recruited 35 people and asked them to predict the result of computerised coin-flips while sitting in an fMRI scanner. They were paid in proportion to their accuracy. In some ‘No-Opportunity trials’, they had to make their predictions beforehand, giving them no room for cheating. In other ‘Opportunity trials’, they simply had say whether they had guessed correctly after the fact, opening the door to dishonesty.
To cover up the somewhat transparent nature of the experiment, Greene and Paxton fibbed themselves. They told the recruits that they were taking part in a study of psychic ability, where the idea was that people were more clairvoyant if their predictions were private and motivated by money. Under this ruse, the very nature of the “study” meant that people had the opportunity to lie, but were expected not to.
What happens when you remember a good deed, or think of yourself as a stand-up citizen? You might think that your shining self-image would reinforce the value of selflessness and make you more likely to behave morally in the future. But a new study disagrees.
Through three psychological experiments, Sonya Sachdeva from Northwestern University found that people who are primed to think well of themselves behave less altruistically than those whose moral identity is threatened. They donate less to charity and they become less likely to make decisions for the good of the environment.
Sachdeva suggests that the choice to behave morally is a balancing act between the desire to do good and the costs of doing so – be they time, effort or (in the case of giving to charities) actual financial costs. The point at which these balance is set by our own sense of self-worth. Tip the scales by threatening our saintly personas and we become more likely to behave selflessly to cleanse our tarnished perception. Do the opposite, and our bolstered moral identity slackens our commitment, giving us a license to act immorally. Having established our persona as a do-gooder, we feel less impetus to bear the costs of future moral actions.
It’s a fascinating idea. It implies both that we have a sort of moral thermostat, and that it’s possible for us to feel “too moral”. Rather than a black-and-white world of heroes and villains, Sachdeva paints a picture of a world full of “saintly sinners and sinning saints”.
Both objects and behaviour can be described as disgusting. The term could equally apply to someone who cheats other people out of money as it could to the sight of rancid food or the taste of sour milk. That’s not just a linguistic quirk. Some scientists believe that the revulsion we feel towards immoral behaviour isn’t based on our vaunted mental abilities, but on ancient impulses that evolved to put us off toxic or infectious foods.
It seems that your facial muscles agree. Hanah Chapman from the University of Toronto has found that both physical and moral disgust cause the levator labii muscles, which run from your eyes to your mouth, to contract. The result: you wrinkle your nose and you purse your lips. Nasty tastes, gross photos and foul play all cause the same physical reaction and the same subjective emotions. When people say that moral transgressions “leave a bad taste in your mouth”, it’s more than just a pretty metaphor.
Chapman began by studying disgust in its more primitive forms – reactions to foul tastes. She recruited 27 volunteers and recorded the electrical activity in their levator labii muscles as they drank small vials of various liquids. If the concoctions were unpleasantly salty, sour or bitter, this group of muscles contracted more strongly than if the liquids were sweet or flavourless. These reactions were a good measure of their subjective opinions – the more distasteful they found the drinks, the more strongly their muscles contracted.
Throughout our language, the vocabulary of physical cleanliness is also used to describe moral cleanliness. We describe saints as pure and thieves as dirty; consciences can be clean and sins can be washed away. But more and more, psychological studies tell us that these concepts are entwined in a very real way. The act of cleaning, or even just thinking about the concept of cleanliness, can influence a person’s moral compass, swinging it towards a less judgmental direction.
This isn’t the first time that I’ve blogged about this. Two years ago, Chen-Bo Zhong and Katie Liljenquist found that volunteers who dredged up a past misdeed were more likely to think of words related to cleaning or show a physical preference for cleaning products. This “Lady Macbeth effect” is reminiscent of the infamous Shakespearean character and her failed attempts to wash her hands of spilt blood.
Simone Schnall and colleagues from the University of Plymouth have expanded on Zhong and LIllenquist’s study by showing that the effect works in the opposite direction. Not only can feelings of moral muck trigger a desire for physical cleanliness, cleanliness can also change how seriously people view a moral transgression.
They asked 40 volunteers to a rearrange 40 sets of four words into sentences. Through this word-game, they ‘primed’ 20 of the volunteers with thoughts of cleanliness by interspersing half of their sets with cleaning-related words, such as pure, washed, clean, immaculate or pristine. The other 20 volunteers only saw unconnected neutral words in all of their sets.