The power of habit

Life is a constant stream of decisions that pit sober reflection against powerful emotions, conscious deliberation against gut instincts. Using complex models and sophisticated experiments, ETH researchers study how we combine these different decision-making strategies.
Doughnut or apple? The confidence we have in these kinds of decisions depends on how attentively we made them (Photograph: Colourbox.com)

One mention of insects is enough to draw a sceptical smile from Michael Siegrist. As Professor of Consumer Behaviour at ETH Zurich, he is constantly reminded how conservative people are when it comes to food. “If we want to make food production more sustainable, insects are probably the hardest way to go about it," he says. "Insects turn almost everyone’s stomach, which is difficult to overcome.”

Siegrist and his team study how consumers are guided by their emotions – and their findings suggest that emotional responses are often more powerful than rational ones. In various experiments, the researchers have confirmed that, when it comes to assimilating information, we are influenced considerably more by symbolic information than by pure facts. In other words, pictures speak louder than words.

Give people the fuel-consumption data for two car drivers, for example, and almost everyone will say that the one who uses less fuel is more environmentally friendly. But tell them that the fuel-saver drives an SUV, while the other driver has a hatchback, and their opinion flips: the SUV driver is now perceived as less environmentally friendly, even though they consume less fuel. “Eighty percent of test subjects jump to the wrong conclusion,” says Siegrist. “I find that astonishing.”

Symbols exert particular power in relation to food. “People say they want their food to come from nature, not technology,” says Siegrist. This stems from a naïve concept of nature that is firmly rooted in our minds, he says – a concept that is heavily promoted by government and by corporate marketing departments. “In fact, we only end up glorifying nature because technology has enabled us to make huge improvements in food safety,” he explains.

«Disgust is a powerful emotion.»      Michael Siegrist

What’s intriguing is how technological change has left a different legacy in our kitchens than in our offices or living rooms. Floppy disks, CRT televisions and CDs have long since disappeared from everyday life – but in the kitchen, new technologies tend to supplement, rather than supplant, old ones. “We don’t really need cans anymore, and we certainly don’t need to prepare our food over an open fire,” says Siegrist. “Yet we still choose to buy canned fruit and barbecue on the patio.”

Siegrist’s observations are based on the findings of the Food Panel Switzerland survey, in which he and his team built up a detailed picture of Swiss consumer behaviour. The researchers also analysed intuitive eating strategies and how a partner’s eating habits can influence our own behaviour. Siegrist’s conclusion is that we only ever make gradual changes to our eating behaviour unless we are forced to do so by external factors. This matches his previous experience: “After all, it’s not like we rethink our eating habits every single day!”

Siegrist also reaps the benefits of technical progress in his own research. “Twenty years ago, most of our studies were based on printed questionnaires,” he says. “Nowadays, we can expose study participants to a whole new array of stimuli thanks to video and virtual reality (VR).” For example, Siegrist’s team recently conducted an experiment into the feeling of disgust, where they asked participants wearing a VR headset to eat a real piece of chocolate while simultaneously watching the virtual depiction of something neutral – in this case a table – or of a defecating dog. Although the dog and the faeces were clearly not real, a large proportion of the second group refused to eat the chocolate. “Disgust is a powerful emotion,” says Siegrist. “And it has a much stronger effect on us than cognition.”

Does intuition help women?

Researcher Katharina Fellnhofer also uses lab experiments to better understand people’s decision-making behaviour. She is currently a Marie Curie Fellow at the Chair of Education Systems, where she is focusing on an aspect that has received very little research attention, namely what role intuition plays in our decision-making process and how we can harness it to make better decisions.

Fellnhofer has developed a new method to help answer these questions. She starts by presenting the test subjects with graphs showing (real) companies’ earnings performance over a five-year period. The participants are then given a short time to decide whether they wish to invest in the companies or not. Half the companies are a good investment, as shown by their earnings performance over the subsequent five years, while the other half are not. “My study method is essentially akin to a game of chance,” she says. “So you would think women would do just as well as men.” In fact, however, women make significantly worse investment decisions than men.

«Intuition is especially helpful for making risky decisions quickly.»      Katharina Fellnhofer

But it turns out there is more than meets the eye in half of the graphs. These contain a hidden message in the form of emotionally charged three-dimensional images that are concealed in the graphs using a special technique and are only perceived subconsciously. Initially, the experiment is run using emotionally neutral images, but when it is repeated with the graphs containing emotionally charged images that intuitively guide the viewer towards the right decision, then female participants do better and achieve similar results to the men. “This shows how women can overcome a disadvantage by drawing on information that is only available through intuition,” explains Fellnhofer.

Fellnhofer noticed a rapid improvement in the study participants’ decisions, which suggests that subconscious learning had taken place. By fine-tuning her measurement method, she now hopes to explore whether intuition can be taught and, if so, to what degree.

Fellnhofer’s conclusion is that intuition can help us make better decisions: “That’s especially true when it comes to making risky decisions quickly.” But she cautions that intuition is affected by all sorts of factors, such as memories of past events. Experience, in particular, plays a pivotal role. “Experienced chess players intuitively see the right move with minimum cognitive effort. That’s what makes them so much faster than beginners,” she explains. Conducting research into intuition is challenging, says Fellnhofer, precisely because it’s so hard to grasp: “Intuition is tremendously multifaceted, which is why we need experiments that include a wide array of input from different disciplines.”

Optimum use of resources

Bringing all these different aspects together is the goal of Professor Rafael Polania, who heads the Decision Neuroscience Lab at ETH. “All organisms make decisions based on the signals they receive from their environment,” he says. “And the more complex the organism, the more complex the decisions.” That said, he notes that all living beings are essentially confronted with the same challenge: how can they make optimum use of the resources that biology has given them in order to make the best possible decisions?

Polania hopes to use mathematical models to predict the behaviour of living creatures: “We try to model the factors that influence our decisions. Then we run experiments to test the model’s predictions.” His work draws on insights from a wide range of disciplines including psychology, computer science, neurobiology and economics.

«The more complex the organism, the more complex the decisions.»      Rafael Polania

Polania believes his findings will have ramifications for many different disciplines. “Economists have long thought that human decisions are fundamentally rational," he says. "That’s why it was difficult to explain why people tend to avoid risks in certain situations even when it goes against rational judgement. This is easier to understand once you take into account our biological limitations.” Polania cites two crucial factors that shape our behaviour. First, our brain processes familiar situations faster and in a more nuanced way than it does new ones. That’s why we find it easier to distinguish between individuals from our own culture than people from far-away countries. “It’s not a question of racism; it’s about how our brain processes information,” says Polania. The second factor is our desire to link new perceptions to previous experiences. “We like things that are new, but not too different from what we already know,” he says. “When we manage to forge a connection between a new experience and something familiar, it gives us a positive feeling.”

Human decision-making processes can also offer interesting insights into the future development of AI. Just like us, machines have to make the best use of limited computing capacity, so it makes sense for them to stick to what they know. Viewed from this perspective, Polania says we shouldn’t be surprised if a chatbot starts making racist comments or forensic software shows a tendency to discriminate against certain groups. But he believes this is something we can change: “If we understand the mechanism that leads to those biases, we can correct them.”

There is one further aspect that guides our decision-making processes – our capacity for introspection. “Acquiring a sense of how well you judge things gives you an important corrective mechanism that helps you realise when you make a mistake, allowing you to make better decisions in the future,” says Polania. In a recent study, he was able to show that it is precisely this ability that distinguishes good leaders. “There are very optimistic people who are convinced they’re always right. And there are pessimistic people who constantly question the decisions they make. Neither of those attitudes is helpful,” says Polania. “You need to find the right balance – and that’s where introspection can help.”