The Marshmallow Test: To What Extent Does Discipline Dictate Success?

“You can have this treat now, or have two when I get back to the room.” 

Sound familiar? Yep, we’re delving into the efficacy of the findings extracted from none other than the Marshmallow Experiment. Just how accurate a reflection of an individual’s future success are the predictable inferences we are able to draw from this renowned study?

In 1970, Walter Mischel, a professor of psychology at Stanford University and his graduate student, Ebbe Ebbesen, found that preschoolers waiting 15 minutes to receive their preferred treat (a pretzel or a marshmallow) waited much less time when either treat was within sight, than when neither treat was in view. “You can have this treat now,” he famously told each 4 and 5-year-old, “or have two when I get back to the room.” Mischel also discovered that children with treats present waited 3.09 +/- 5.59 minutes, while children with neither treat present waited 8.9 +/- 5.26 minutes. The study suggested that gratification delays in children involved suppressing rather than enhancing attention to expected rewards. 

For example, some children who waited with both treats in sight would stare at a mirror, cover their eyes, or talk to themselves, as opposed to fixating on their treat of choice, which just so compellingly sat in front of them. Mischel concluded that there were strong bivariate correlations (analyses whether and how two variables covary linearly) a child’s ability to delay gratification just before entering school and both adolescent achievement and socioemotional behaviours. Indeed, according to well-publicised studies in the decades since, it was uncovered that the children who failed to employ successful resistance generally grew into their teens, 20s, and even 30s quicker to frustrate, weaker in academic and social skills, not to mention with more drug use, mental health and various issues pertaining to weight.

You may be thinking, what about the last time I may or may not have sneaked in some dessert before dinner? Well, Tyler W. Watts, Greg J. Duncan, and Haonan Quan were three psychologists very much in the same boat as you. Intrigued but simultaneously skeptical of Mischel’s findings, the trio extended Mischel’s famous marshmallow study by switching out the sample for children whose mothers had not completed college instead. Watts, Duncan and Quan found that an additional minute waited at age 4 predicted a gain of approximately one-tenth of a standard deviation in achievement at age 15. However, the bivariate correlation they were able to produce was only half the size of those reported in the original studies and was reduced by two-thirds in the presence of controls for family background, early cognitive ability, and the home environment. Most of the variation in adolescent achievements came from being able to wait at least 20 seconds. You’ll be even more pleased to know that associations between delay time and measures of behavioural outcomes were much smaller and rarely statistically significant. (This is where we both let out a big, fat sigh of relief.)

More interestingly, Mischel himself conducted a follow-up study of his own marshmallow experiment, which has been praised for being highly influential. And his original experiment? Not so much. You see, Mischel was initially more interested in the coping strategies the kids implemented to not eat the marshmallow than in potential predictive powers arising from measuring how they waited. After all, harnessing self-control in order to delay gratification - the ability to resist temptation now to attain something you want further down the line - is required to achieve goals, enormous and miniscule. Mischel aimed to identify effective tactics, as unlike famous psychologists before him, he believed that delayed gratification skills could be taught.

Yet, it was actually Mischel’s follow-up research which elicited the initial uproar of fame enjoyed by the marshmallow test. In study after study, he and his research partners documented multiple ways his least patient 5-year-old treat eaters lagged behind the waiters as they grew into teenagers, 27-year-olds and 37-year-olds. The impact of this on the public was magnanimous, to say the least. Parents, policymakers, and educators alike embraced the studies’ unwritten take-home message: to raise successful, responsible kids, we must teach them to resist that first marshmallow. Schools incorporated marshmallow tests and self-control techniques into curriculums. Parents devised their own marshmallow tests. Success gurus gave TED Talks about it. Sesame Street’s notoriously out-of-control Cookie Monster starred in a series of videos demonstrating the delay of gratification skills he learned from Mischel. If all this recognition wasn’t enough, the scientists who pioneered this project (including Mischel) won the 2015 Golden Goose Award, bestowed by a group of congressmen for government funded research that leads to significant public benefits.

However, Mischel’s follow-up study has also been criticised by the contradicting findings of a subsequent longitudinal study. This study casts doubt that a preschooler’s response to a marshmallow test can predict anything at all about their future. It reveals that kids who quickly gave in to the marshmallow temptation are generally no more or less financially secure, educated or physically healthy than their more patient peers. The amount of time the child waited to eat the treat failed to forecast a dozen adult outcomes the researchers tested, according to the Journal of Economic Behaviour and Organisation, including:

• Social standing

• Net worth

• High interest-rate debt

• Diet and exercise habits

• Smoking

• Procrastination tendencies

• Preventative dental care

UCLA Anderson’s Daniel Benjamin, who brings expertise to the study that includes behavioural economics and statistical methodology, concludes in an interview: “with the marshmallow waiting times, we found no statistically meaningful relationships with any of the outcomes that we studied.”

Overall, the evidence you can glean from the marshmallow test seems to be shrouded in ambiguity and lacks predictive validity. Additionally, with the studies which were carried out longitudinally on the marshmallow test, other confounding variables could have very well contributed to the prediction of an individual’s future successes, should such a finding emerge, such as having supportive and unconditionally loving parents. But maybe one day, just one day, it will be possible to harness the power of delayed gratification in order to achieve self-actualisation.

Reference List

Navidad, A. (2023). Marshmallow Test Experiment | Simply Psychology. [online] www.simplypsychology.org. Available at: https://www.simplypsychology.org/marshmallow-test.html. 

Watts, T.W., Duncan, G.J. and Quan, H. (2018). Revisiting the marshmallow test: A conceptual replication investigating links between early delay of gratification and later outcomes. Psychological Science, 29(7), pp.1159–1177. doi:https://doi.org/10.1177/0956797618761661. 

Gill, D. (2021). New Study Disavows Marshmallow Test’s Predictive Powers. [online] UCLA Anderson Review. Available at: https://anderson-review.ucla.edu/new-study-disavows-marshmallow-tests-predictive-powers/. 

Sandilands, D. (2014). Bivariate Analysis. Encyclopedia of Quality of Life and Well-Being Research, [online] pp.416–418. doi:https://doi.org/10.1007/978-94-007-0753-5_222.