Measuring grit through the ‘Marshmallow Experiment’

By John Langhorne / Guest Column

Psychology evolved from philosophy and our natural curiosity about ourselves. The level of sophistication of experiments has improved markedly as the knowledge base has grown.

Please consider a couple fascinating experiments. The first began in 1968 and is continuing and the second in the past several years.

From 1968-1974, Walter Mischel carried out a series of studies with about 550 pre-school children that have come to be known as the marshmallow experiment. The beauty of this experiment is its simplicity. A 3-5 year-old child is playing in a preschool room with an experimenter, who then poses an interesting task to the child. Giving the child a marshmallow and saying she would leave the room, the researcher promises, if the child resists eating the marshmallow, they would receive a second marshmallow.

She was absent 15 minutes – infinity for a 3-year old. As you can imagine, watching these very young people struggle to not eat the marshmallow is fascinating. Some years later the experiment added video recordings which are available online Only about a third of the children were able to earn the second marshmallow. The experiment’s intent was to begin to understand the nature of delayed gratification.

For an amusing three minutes go to

About 10 years later the researchers found differences between the two groups and the results were nothing short of astounding. Children who could delay gratification exhibited more self-control in frustrating situations, yielded less to temptations, were less distracted when trying to concentrate, were more intelligent, self-reliant and confidant and trusted their own judgment.

When under stress, they did not go to pieces, were less likely to become rattled and disorganized or revert to immature behavior. Likewise, they thought and planned more, and when motivated, were more able to pursue their goals. They were also more attentive and able to respond to reason and were less likely to be side-tracked by setbacks. When comparing the bottom third to the top third there was a 220 point difference in their SAT scores.

Another study at ages 25-30 showed those in the top third had more successfully reached long-term goals, had less drug use and lower body mass indices. They were more adaptive in coping with interpersonal relations and maintaining relationships.

Wow — a single, simple task could validly predict success in life. This research has been replicated across cultures and continents and continues today.

Recently, Angela Duckworth developed a short survey to measure grit. She defines grit as “passion and perseverance for long-term goals.”

Studies across many settings showed that the grit score highly correlates with workplace success. This is a “how-to” empirical follow-up to the marshmallow experiment. I find this amusing because I am often asked, “what is the single most important key to success?” My answer has been “I know of no research on this, but I believe it’s hard work.”

In chapter 1 from her upcoming book “Grit: The Power and Passion of Perseverance,” Ms. Duckworth describes how the survey predicts success in the so-called Beast Barracks at West Point.

Two assessment tools, a task and a test, are probably the best extant predictors of performance in the workplace. No psychological test predicts human performance with such validity.

Recently, Mr. Mischel published a book titled “The Marshmallow Experiment.” It is a well-written, lucid account that reviews many practical findings about self-control useful in our everyday lives.

Beginning with an overview of our current understanding of how nature and nurture interact, the book marshals a serious amount of evidence that grit is learned. This means there are tactics people can enact to improve their and their children’s grittiness. For example, it is not a good practice to tell your children they are smart, it is much better to tell them they are hard workers and reward them for such. Little can be done to improve IQ and so it is a losing strategy.

Have you noticed that people who grew up on farms are usually successful? Their grittiness scores are probably pretty high. This is because such children begin helping out on the farm as soon as they are able. I have encountered both high school and college students who have never worked. I once consulted to a CEO who noted his child’s best experience was working at a McDonalds because “they taught her how to work.”

John Langhorne is owner and principal of Langhorne Associates, His most recent book, “Beyond IQ: Practical Steps to Find the Best You,” is available digitally at Amazon.