The Marshmallow Test - What We've Been Learning About Self-Control and Delayed Gratification

One of the more famous psychological experiments is known by many as “the marshmallow test”. At its most basic, children are given the option of eating one marshmallow now (which is sitting in front of them), or getting two marshmallows if they wait until the experimenter returns. Cute videos have emerged of children wrestling with their self-control as they try not to eat the marshmallow in front of them. As cute as the videos are, the original experiment, by Walter Mischel and his colleagues, had a profound impact on our understanding of self-control and delayed gratification in humans and continues to fuel further research.
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In 2014, Dr. Mischel published a book called The Marshmallow Test: Mastering Self-Control which describes the original study, but also goes into detail about the long term findings from the research, as well as how he and his colleagues have expanded the study and how other psychologists have contributed to the study of self-control and delayed gratification. Over the decades, psychologists have better understood how the mind works when we resist temptations and succeed; self-control is all about changing how we think.

Original Study

The development of “the marshmallow test” began in the 1960s. Dr. Mischel is quick to point out that the name “the marshmallow test” was adopted by the media and that the original experiments used a variety of treats from which the children were able to choose. A preschool student was given a choice: he could have one reward (such as a marshmallow) right away, or a larger reward (two marshmallows) if they waited, alone, for up to 20 minutes.

​These children were followed over the years and now decades, and researchers found some surprising connections. In the first follow-up, the more seconds a child was able to wait at age 4 or 5, the higher their SAT scores in high school. Around age 30, those who waited longer in preschool had a lower body mass index, sense of self-worth, and coped better with stress. Such a simple task with children turned out to have greater meaning over most of a lifetime.

Hot and Cold Systems

The results are fascinating, but the research does not end there. The researchers changed the experiment in a variety of ways to try and answer questions about how some kids were able to wait and to better understand what helps self-control and what hinders it.

​Dr. Mischel explains that a key to understanding our self-control is to understand that we have “hot” and “cool” systems. The hot system includes our more basic drives and emotions, our impulses. The cool system develops later in our brains (centred primarily in the prefrontal cortex of the brain) and enables more rational and strategic behaviour. The systems are constantly working together, but it is the cool system that is the root of our self-control ability. Even just thinking about immediate rewards triggers the hot system, while thinking about delaying activates the cool.

​Samuel McClure and colleagues (2004) found that using functional MRI (fMRI; a technology that measures brain activity), they could predict whether an individual would choose a smaller, but immediate payoff, or a larger delayed payoff. These different systems are emotional, but they are also physically specific to different areas of our brain. As well, as one system is active, the other is less active. Dr. Mischel states: “the challenge is to know when it’s best to let the hot system guide your course, and when (and how) to get the cool system to wake up”.

If - Then Plans

Based on Mischel’s studies, researchers Peter Gollwitzer, Gabriele Oettingen and their colleagues used If-Then implementation plans to help people achieve difficult goals and overcome challenges. The idea is that an action starts automatically when a specific situation occurs.

​For example: when the clock hits 5pm, I will read my textbook; when the dessert menu is served, I will not order. The If can also be something like: when I’m bored, when I get a craving, when I’m angry. By practicing these situations, you can train your impulsive or hot system to trigger the response you’ve trained instead of what the initial reaction was.

Distance from Temptation

When Mischel studied the preschoolers, he and his colleagues found that children who were able to wait for more treats used strategies to distance themselves from the temptation. Some created physical distance by pushing the treats away, not looking at them, or closing their eyes. In another study, children were asked to think about the treats as if they were a picture instead of the real thing, creating psychological distance.

​Another strategy was to think about practical parts of the treat (such as its shape, colour, or size) as compared to thinking about the desirable features (how it would taste, its smell, or the texture when you bite it). Not surprisingly, thinking about a sweet gooey marshmallow made them more tempting than thinking about a white, round marshmallow.

Heat the Future

Not surprisingly, thinking about desirable features as mentioned above, activates our hot system, whereas the practical parts activates the cool. Similarly, our view of the present is that it is tangible and we are experiencing tempting things as opposed to our view of the future, which is more distant and practical.

​Training ourselves to focus on the future and long-term benefits or consequences to what we are doing will help to cool our thinking of the present and make more controlled decisions. 

Connection To Your Future Self

Hal Hershfield and his colleagues found that people differ in how they feel about their future selves, which shows up in their actual brain activity. Participants were asked to think about how they might be in 10 years and rate how similar they felt to their future self. The researchers found that people who rated less overlap between their current self and future self were more likely to prefer immediate rewards compared to those who envisioned greater overlap. So, the more you can think of your self now as being similar to yourself later, the more likely you are to be able to save money or make healthy choices for the future.
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Despite the early research indicating that children who showed willpower at an early age showed signs of it later in life, Mischel points out that the research he has been a part of in the decades following has shown that will-power is not something that you either have or do not have. Self-control skills can be learned and expanded with practice, strategy, and motivation. 

By Kristi MacDonald
Clinical Associate

Mischel, W. (2014). The marshmallow test: Mastering self-control. New York, NY: Little Brown and Company.