I am very wary of a story that fits together too well.

Life is a mess, and most of the puzzle pieces have been damaged or lost over the years. Even if you believe in God, as I do, the doctrine of original sin should make us wary of neat narratives. So, in other words, we should expect chaos in our lessons.

To me, one of the most interesting, and troubling aspects of pop science’s favorite “marshmallow test”¹ was the way it seemed to forecast a life of success or failure for the children tested. This always stood out to me, no matter how many times I heard it, so I uttered an audible “ahhhh…huh!” when I read this in Algorithms to Live By²:

When Walter Mischel ran his famous “marshmallow test” in the early 1970s, he was trying to understand how the ability to delay gratification develops with age. At a nursery school on the Stanford campus, a series of three-, four-, and five-year-olds had their willpower tested. Each child would be shown a delicious treat, such as a marshmallow, and told that the adult running the experiment was about to leave the room for a while. If they wanted to, they could eat the treat right away. But if they waited until the experimenter came back, they would get two treats.³

Unable to resist, some of the children ate the treat immediately. And some of them stuck it out for the full fifteen minutes or so until the experimenter returned, and got two treats as promised. But perhaps the most interesting group comprised the ones in between—the ones who managed to wait a little while, but then surrendered and ate the treat.⁴

These cases, where children struggled mightily and suffered valiantly, only to give in and lose the extra marshmallow anyway, have been interpreted as suggesting a kind of irrationality. If you’re going to cave, why not just cave immediately, and skip the torture? But it all depends on what kind of situation the children think they are in. As the University of Pennsylvania’s Joe McGuire and Joe Kable have pointed out, if the amount of time it takes for adults to come back is governed by a power-law distribution—with long absences suggesting even longer waits lie ahead—then cutting one’s losses at some point can make perfect sense.⁵

In other words, the ability to resist temptation may be, at least in part, a matter of expectations rather than willpower. If you predict that adults tend to come back after short delays—something like a normal distribution—you should be able to hold out. The Average Rule suggests that after a painful wait, the thing to do is hang in there: the experimenter should be returning any minute now. But if you have no idea of the timescale of the disappearance—consistent with a power-law distribution—then it’s an uphill battle. The Multiplicative Rule then suggests that a protracted wait is just a small fraction of what’s to come.⁶

Decades after the original marshmallow experiments, Walter Mischel and his colleagues went back and looked at how the participants were faring in life. Astonishingly, they found that children who had waited for two treats grew into young adults who were more successful than the others, even measured by quantitative metrics like their SAT scores. If the marshmallow test is about willpower, this is a powerful testament to the impact that learning self-control can have on one’s life. But if the test is less about will than about expectations, then this tells a different, perhaps more poignant story.⁷

A team of researchers at the University of Rochester recently explored how prior experiences might affect behavior in the marshmallow test. Before marshmallows were even mentioned, the kids in the experiment embarked on an art project. The experimenter gave them some mediocre supplies, and promised to be back with better options soon. But, unbeknownst to them, the children were divided into two groups. In one group, the experimenter was reliable, and came back with the better art supplies as promised. In the other, she was unreliable, coming back with nothing but apologies.⁸

The art project completed, the children went on to the standard marshmallow test. And here, the children who had learned that the experimenter was unreliable were more likely to eat the marshmallow before she came back, losing the opportunity to earn a second treat.⁹

Failing the marshmallow test—and being less successful in later life—may not be about lacking willpower. It could be a result of believing that adults are not dependable: that they can’t be trusted to keep their word, that they disappear for intervals of arbitrary length. Learning self-control is important, but it’s equally important to grow up in an environment where adults are consistently present and trustworthy.¹⁰

You know what also forecasts a tough life, besides purportedly missing grit? Undependable adults raising children. You see, most of the self-made men and women found at Trump rallies¹¹, had pretty okay parents, and this simple fact enables success far more than we credit it. This is the missing, messy fact that took the neatness out of the lesson for me. I can believe the lesson more, because it is far more complicated than simple childhood willpower.

This also breaks my heart a little, because I am forced to confront the fact that too many kids are surrounded by unreliable adults. These unreliable adults may be criminals, drug addicts, or good people trying their damndest to put food on the table, too often failing to follow through on their promises.

Beware neat lessons.

Before you go, please consider filling out my survey and signing up for my newsletter.