Inside the Intuitive Mind: The Cookie Jar Effect

 

In my blog post on Nudges, I talked about why grocery stores sell higher-profit items at eye level (because people are more likely to buy those). That's an example of "design architecture," defined as environmental structures that encourage or discourage particular forms of behavior. NPR's Planet Money podcast highlighted another form of design architecture in a recent episode: package size. 

After many years of offering only a few standardized sizes for their products, manufacturers have begun selling the same products in a much wider range of packages. Coca-Cola was a pioneer in this area of marketing, launching tiny cans for health-conscious consumers and also giant bottles for families and parties. The price of the actual soda can vary along with its package size: People are actually willing to pay a higher price per ounce when the can or bottle is smaller, because of the perception of convenience or health benefits. But size can also have an effect on how much of a product people will consume. That's the effect I want to explore here.

When a product is more abundant, as is the case with larger packages, people are willing to use more of it. A cookie jar on the kitchen counter is a great example: When the jar is full, people are more likely to grab a couple of cookies and eat them; on the whole, they probably end up eating more cookies sooner than they would have when buying individually packaged items. The converse is also true: Everybody takes a generous helping of cake at the beginning, but the leftovers may linger for a week -- and nobody wants to be the rude person who took that very last piece. (In our house, there's the added disincentive that the person who takes the last piece also has to rinse the pan). 

The cookie-jar effect is particularly relevant when it comes to food. As I have written previously, diet is an especially difficult health behavior to change. But exerting control over portion size is one of the more effective ways to do it. Many of us discovered during the COVID-19 pandemic that we didn't eat particular foods as often, just because we didn't have them at home at shopping was more difficult. In an extreme example, my family went for 3 months without eating out. (I had a particular craving for French fries by the end of that time, and interestingly I discovered that they weren't as good as I remembered them). Many people have found that not buying a particular type of food is an effective support for a diet, and it may be easier to control one's purchasing behavior in the store than one's eating habits in the kitchen. 

Buying smaller packages of food may be another effective strategy. When there's a large package of some food in the house, we eat more of it than we might otherwise. As an example, here's a large container of pretzel bites (delicious!) that we got this summer from our local grocery store: 

There were about 30 of these little pretzel rolls, and they were all relatively small. It seems like the type of food you could snack on without too much risk because of the small portions. But that also made it harder to stop at just eating one! Because they were small, we also didn't feel bad about frequent snacking. Also note that the tub is not re-sealable: Once it was opened, the pretzels immediately started to go stale, and nobody wants to be responsible for that. Finally, this isn't a food item we buy too often  -- actually, I can't remember us ever getting it before. We expected this tub of food to last a week. But as a result of so many psychological factors stacked up in favor of eating, it was barely 24 hours before the container was empty. 

Creating scarcity around food items can make them more appealing to us, but can also increase our self-control over how much of them we eat. Scarce resources are more precious, and we have a natural tendency to conserve them. We can harness that tendency as a way to "trick" the Intuitive mind, in a way that promotes desired behaviors in the realm of diet change. With the tub of pretzels, for example, we could have re-packaged the food into small plastic snack bags with just 2 or 3 items in them. That would have helped to put the brakes on eating after a small amount; it would have removed the incentive to eat the food up quickly before it went stale, and it might have gotten the food off the counter so that we weren't tempted to eat it all the time. The same food item in different packaging might not have presented such strong incentives to eat.

Naturally, our interests as consumers are not always the same as the manufacturer's interests. The pretzel company hopes I love their food, eat it all, and go back out tomorrow to buy more. But that's not in my best interest. With an understanding of the Intuitive mind, perhaps the next time I can counteract the unhealthy incentives of the pretzel tub and achieve a healthier result!