The Stanford Marshmallow Test

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Let’s say you are looking at a marshmallow. You have two options. You can either wait for the first marshmallow and get a second marshmallow. Or, you can have one marshmallow now - but then you’re done. 

How long would you wait for the second marshmallow? Would you wait for the second marshmallow?

This was the dilemma facing preschool-age children in the 1960s. Little did they know that the way they handled the dilemma would be part of one of the most famous psychological studies of all time. In this video, I’m going to tell you all about the Stanford Marshmallow Test: what it was, what it’s said about success, and the impact it’s had on psychology to this day. 

The Stanford Marshmallow Test 

The premise of the test was simple. Stanford professor Walter Mischel and his team put a single marshmallow in front of a child, usually 4 or 5 years old. They told the child that they would leave the room and come back in a few minutes. If the child ate the marshmallow, they would not get a second. If the child waited until the researcher was back in the room, the child would get a second marshmallow. 

Researchers recorded which children ate the marshmallow and which one waited. And then the researchers waited. When the children were teenagers, the researchers revisited the children and asked their parents a series of questions about their cognitive abilities, how they handled stress, and their ability to exhibit self-control under pressure. They also looked at the child’s SAT scores. A few years later, the researchers tested the participants again on their self-control. 

What did they find? In short, Mischel and his team found that developing self-control as a child had a profound impact on the child’s later success in life. Success came in many forms. In general, the children who waited for the second marshmallow:

  • Scored higher SAT scores
  • Reported lower levels of substance abuse
  • Were less likely to be obese 
  • Had better social skills and self-control, according to their parents

Due to the nature of the experiment, the results were published in the 1980s and the 1990s. Since then, the world of psychology has regarded the study as one of the important studies, paving the way for different ways of looking at how personality influences and predicts success. 

Why Would Children Eat The Marshmallow Right Away? 

The Marshmallow Test was able to give researchers a link between self-control and success. In short, having self-control as a child could influence success as an adult. But what influenced self-control? Not all children grabbed the marshmallow right away. 

Mischel and his team developed a “hot-and-cool” system of thinking that explained why children would have eaten the marshmallow immediately. This same system could be applied to any task that involves instant gratification, like making a purchase or smoking a cigarette. 

The “cool” system is where most of are when we’re not tempted. It’s the cognitive ability to think about long-term benefits. We know that smoking is bad for us, and resisting a cigarette will result in long-term health. We know that we will get more marshmallows if we wait. We know that if we go to the gym instead of hitting the snooze alarm, we will feel more awake later and more healthy in the long run. 

But “hot” stimuli threaten that cool system. When things warm up and get hot, our behavior becomes impulsive. We smoke the cigarette, take the marshmallow, and hit the snooze. 

Why do some people “heat up” faster than others? Why are some stimuli are “hotter” than others? These are questions that psychologists like Mischel are still trying to solve. 

Additional Studies Offer Different Explanations 

The Stanford Marshmallow Test took data from a relatively small and not exactly diverse group of participants. Not all researchers were convinced that the test had found the one true key to success. So a more recent study set out to redo the Marshmallow Test, focusing on different social and economic factors that could also play into a child’s success.

The main factor they chose was the mother’s educational background. They split participants into groups based on whether or not the mother had obtained a college degree. Researchers also controlled for factors like family background, early cognitive ability, and the child’s environment at home. 

In short, they found that self-control didn’t exactly have the impact on success that the Marshmallow Experiment said it did. Children who came from more wealthy homes were more likely to practice self-control. When the researchers accounted for social and economic factors, they found that self-control wasn’t necessary in predicting success. 

This doesn’t just put the results of self-control into question. It also questions why children grabbed the marshmallow in the first place. Researchers have offered different opinions, including thoughts on how scarcity impacts a child’s ability to take and use resources. Think about it. Wealthy kids don’t have too many problems waiting for food, toys, or other things. Their parents can afford it. They’ll get it. But kids from lower-income families have more to worry about. Food might be scarce. A parent may promise to bring their kids to a nice restaurant or buy them a nice toy, but may not be able to follow through. If something is right in front of you, you might as well take it - you can’t guarantee it will be there later, or that you’ll get a reward for waiting. 

The Impact of the Marshmallow Test

While recent studies have claimed to “debunk” the Marshmallow Test, it’s impossible to deny that the impact of the study. Mischel’s work was able to show the world how certain personality traits impacted a child’s chance at success. Further work has since been done on different personality traits and how they relate to success in business, love, etc. We might know the terms “growth mindset” or “emotional intelligence” if the Marshmallow Test didn’t exist. 

The Marshmallow Test is not the only classic experiment that has recently undergone criticisms. Psychology is currently undergoing what is called a “replication crisis.” Replications of world-renowned experiments like The Marshmallow Test and the Stanford Prison Experiment show that these tests aren’t as solid or accurate as were once taught in schools. Like any type of study that involves the scientific method, psychology is always evolving and psychologists are continuing to tweak, change, or adjust theories that don’t hold up to modern tests. 

Self-control does have an impact on behavior and possibly success, but it’s up to the current and future generations to learn more about just how self-control is influenced, and influences other personality traits and factors.

Reference this article:

Practical Psychology. (2019, December). The Stanford Marshmallow Test. Retrieved from

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