In 1960, Walter Mischel and Ebbe B. Ebbesen of Stanford University conducted an experiment that would inform the next few decades of child development programs, into present day. Dubbed the “Marshmallow Experiment,” the study was designed to test children’s ability to delay gratification. Children aged 4 to 6 were told they could have a treat (marshmallow) immediately, or they could wait 15 minutes — at which time, they would receive two treats. Most children tried to delay, employing various tactics to get through the excruciating 15 minutes, but only one-third succeeded. Follow-up studies later linked the ability to delay gratification at a young age to higher test scores and increased general competence later.

But there were a few flaws with the study. One, its subjects were children from the highly educated Stanford University community, and two, the follow-up ratings of greater competence relative to peers was given by parents — hardly unbiased parties.

Tyler W. Watts, an assistant professor of research and postdoctoral scholar at New York University’s Steinhardt School of Culture, Education, and Human Development, and colleagues set out to test whether the ability to delay gratification was as predictive of later accomplishments when these flaws were accounted for. The team used a larger and more diverse sample of children than the original study. Published in the journal Psychological Science, the team’s study upheld the link — but found it less significant than previously thought.

The new study discovered that while the ability to resist temptation and wait longer to eat the marshmallow (or another treat offered as a reward) did predict adolescent math and reading skills, the association was small and disappeared after the researchers controlled for characteristics of the child’s family and early environment. And there was no indication that it predicted later behaviors or measures of personality.

While there’s no question the ability to delay gratification is an important skill, the authors concluded that early childhood education programs focused only on teaching young children this skill, without building others in tandem, are likely to be ineffective.

“Our findings suggest that an intervention that alters a child’s ability to delay, but fails to change more general cognitive and behavioral capacities, will probably have very small effects on later outcomes,” Watts explained. “If intervention developers hope to generate the kinds of improvements associated with the original marshmallow study, it is likely to be more fruitful to target the broader cognitive and behavioral abilities related to gratification delay.”

The data for this study were drawn from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, a geographically diverse dataset widely used in the field of developmental psychology. In addition to using a larger sample (918 children), Dr. Watts created a subsample based on maternal education and focused much of the analysis on children whose mothers had not completed college by the time the child was born. This subsample was more representative of the racial and economic makeup of the broader population of children in the U.S.

“Of course, these new findings should not be interpreted to suggest that gratification delay is completely unimportant, but rather that focusing only on teaching young children to delay gratification is unlikely to make much of a difference,” Watts said.

In other words, delayed gratification is an important skill for kids to learn — just like all the other skills.