Changing Behaviour Using the CAN Approach

By Brian Wansink  

A few years ago, the New York State Department of Health asked my colleagues and I a burning question: how much would the government need to subsidize fruit in school lunchrooms, so that children would select and eat five per cent more of it?

A quick visit to local schools showed that fruit was being sold in metal chafing dishes, in a dim corner of the serving line, under a sneeze shield. The 50¢ price tag wasn’t the issue: the young students didn’t even know the price of the fruit, as it would simply be deducted from their pre-paid debit account, set up by their parents or the USDA. We found that with two simple steps — arranging the fruit in attractive bowls and placing it in a well-lit part of the line — fruit sales increased by an average of 103 per cent over one semester.

These simple changes accomplished three goals: they made the fruit more convenient to select; they made it appear more attractive; and they made it appear more normal or ‘reasonable’ to choose fruit. This example illustrates the CAN Approach to changing behaviour. In dozens of studies in homes, grocery stores, restaurants and schools, this approach has been found to guide parents, shoppers, restaurant goers and students to select healthier foods. We have found this approach to be much more effective than banning or eliminating favourite foods, or artificially restricting what someone can order.

Let’s take a closer look at each element of the CAN approach.

1. Make it More Convenient to Select

Healthy foods need to be made the most convenient choice — easy to see, pick up and consume. In one study, when one of the food lines in a cafeteria was redesigned to conveniently offer only pre-packaged healthy foods (such as salads), sales of these foods increased by 77 per cent within two weeks. There are three aspects to the degree of ‘convenience’ of a particular product.

The way it is offered. If you ask children why they don’t eat more apples, 5- to-11 year-olds will say that they are too big for their mouths or that they get stuck in their braces, and adolescent girls say fruit is too messy. The solution: provide pre-cut fruit. When we put fruit sectioners in lunchroom kitchens, children ate 70 per cent more fruit.

The amount of physical effort required. Consider why 100-calorie packages have been so effective at reducing how much people consume in one sitting. One posited reason has to do with the inconvenience of opening a second or third bag, and the convenience of being able to pause and ask, ‘Am I really that hungry?’

The amount of cognitive effort required. One popular technique for changing behaviour is to change defaults. For instance, if a person is automatically given bottled water with their combo meal — unless they explicitly ask for a soft drink — water consumption would dramatically increase. Not only would this lead to water being perceived as the ‘normal’ choice, it would also make it the ‘cognitively convenient’ choice.

2. Make it More Attractive to Select

The healthy choice needs to be made more attractive, relative to what else is available, which could mean it is more attractively named, more attractive in appearance or more attractively priced. Even simply giving healthy food a descriptive name makes it more attractive. For instance, ‘dinosaur trees’ are more exciting for a child and taste better than ‘broccoli’. Perhaps the measure that is most relevant for new product developers and food marketers is consumers’ ‘willingness to pay’. It is important to understand how small changes to peripheral cues around a product can raise its value and lead consumers to be willing to pay more. One study presented diners with brownies on paper plates, normal plates or fine china, and found that the nicer plates not only increased taste-ratings of the brownies but doubled the price people were willing to pay for them.

3. Make it More Normal to Select

Most consumers prefer what they think is ‘normal’ to order, purchase, serve and eat. For instance, when 50 per cent of the milk cartons in a cooler are white (vs. chocolate), children are nearly three times as likely to select white milk than when only 10 per cent is white. The same applies at home: when healthier food is placed on the front or middle shelf of a cupboard or refrigerator, it is more frequently taken and is rated as more ‘normal’ to select. As a result, it is possible for industry to effectively suggest norms. Although government’s approach to suggesting norms has often been top-down and prescriptive, industry’s approach of simply changing package sizes (i.e. the 100 calorie pack) or packaging (re-sealable bottles) has led to new consumption norms and reduced intake, while profitably increasing the price per ounce of these products. 

In the end, eating better and exercising more are decisions that we should all be motivated to make. Behavioural scientists are well placed to effectively help us transform our collective behaviour — and the supporting behaviour of restaurants, grocery stores, schools and workplaces.