What Happened to the Kids from the Marshmallow Test

A child was seated at a table with a treat placed in front of her and told: you can eat it now, or wait until the adult comes back, and then you will get two. The adult left for about 15 minutes. The children coped however they could: they turned away, sang, and covered their eyes with their hands.

Many years later, researchers contacted some of the participants and found that those who had held out longer, on average, did better in school and encountered difficulties less often. That led to a conclusion that spread through books: the ability to wait determines your fate.

The problem with the original study was not its method, but the size and makeup of the group. The children were mostly from university employees' families, so they came from a very similar and privileged environment, and there were few of them. With data like that, a chance coincidence can easily be mistaken for a pattern.

In the new study, researchers recruited ten times more participants from different backgrounds. A link between waiting at age 4 and later success was found, but it was about half as strong. Most importantly, it almost disappeared after taking the mother's education and the family's income into account.

Another explanation emerged for the behavior itself. In an experiment where an adult had deceived the child once beforehand, the children waited noticeably less. In other words, waiting measures not only self-control, but also experience: whether it's worth believing that what was promised will actually be delivered.

For a child whose food appeared unpredictably, eating it right away is a sensible strategy, not a weakness. So the test partly measured the family's living conditions, and those same conditions later affected the child's fate. The link is real, but the cause is not where people looked for it.