El experimento marshmallow

We Didn’t Eat the Marshmallow. The Marshmallow Ate Us

In a series of famous experiments in the 1960s and ’70s conducted by the Stanford psychologist Walter Mischel, preschoolers were invited to sit alone in a room furnished only with a small desk. On the desk sat two marshmallows (or equivalently tempting treats) and a bell. The researcher told each child that he had to leave, but that when he returned, she could eat both marshmallows. If she wanted one marshmallow before then, however, she could ring the bell and eat one, but not both. Then the researcher shut the door, leaving the child alone with the forbidden marshmallows.

Some children gobbled a marshmallow the minute the door was closed, while others distracted themselves by covering their eyes, singing and kicking the desk. One resourceful child somehow managed to take a nap. But here’s the part that made the experiment famous: In follow-up studies, children who had resisted temptation turned out years later to be not only skinnier and better socially adapted, but they also scored as much as 210 points higher on their SATs than the most impatient children in the studies did.

I think I speak for thousands of my fellow Americans when I say that the first time I read about Mischel’s marshmallow study — in Daniel Goleman’s best seller, “Emotional Intelligence” — I imagined myself at age 4, staring at that fateful marshmallow. The tale of the marshmallows, as presented in Goleman’s book, read like some science-age Calvinist parable. Was I one of the elect, I wondered, a child blessed with the moral fortitude to resist temptation? Or was I doomed from age 4 to a life of impulse-driven gluttony?

Clearly I’m not alone in this reaction. Search for “marshmallow experiment” on YouTube, and you’ll find page after page of home-video versions of the experiment in which 4-year-olds struggle not to eat a marshmallow. The marshmallow study has been the subject of TED talks. The New Yorker published a long article about it. Radiolab did a show on it.

If you doubt the ubiquity of the Mischel study, try this simple experiment: Put a few social-policy geeks in a room and ask them about willpower, then see how long it takes before somebody brings up the 4-year-olds and the marshmallows. My bet is you wouldn’t have to wait more than a minute or two.

The marshmallow study captured the public imagination because it is a funny story, easily told, that appears to reduce the complex social and psychological question of why some people succeed in life to a simple, if ancient, formulation: Character is destiny. Except that in this case, the formulation isn’t coming from the Greek philosopher Heraclitus or from a minister preaching that “patience is a virtue” but from science, that most modern of popular religions.

But science isn’t religion or philosophy; it’s science. And in this case, as remarkable as Mischel’s experiments were, our extrapolations from them leave plenty of room for skepticism. Mischel’s original studies focused on 653 children, all of them students at the Bing Nursery School on the Stanford campus, which served children of professors and graduate students. The studies weren’t originally designed to look at long-term outcomes; that idea occurred to Mischel later only when he asked his own children, who had attended the Bing school, how his research subjects were faring as they grew older. So for the follow-up studies conducted in the 1980s, Mischel and his colleagues were able to track down 185 of the original children, 94 of whom were willing to provide SAT scores. Mischel, today a professor at Columbia, continues to follow the Bing study group and contributed to a 2011 brain-imaging study of a small number of his test subjects, now in their 40s, which showed differing brain activity in those who were able to delay gratification and those who weren’t.

But how our brains work is just one of many factors that drive the choices we make. Just last year, a study by researchers at the University of Rochester called the conclusions of the Stanford experiments into question, showing that some children were more likely to eat the first marshmallow when they had reason to doubt the researcher’s promise to come back with a second one. In the study, published in January 2013 in Cognition under the delectable title “Rational Snacking,” Celeste Kidd, Holly Palmeri and Richard N. Aslin wrote that for a child raised in an unstable environment, “the only guaranteed treats are the ones you have already swallowed,” while a child raised in a more stable environment, in which promises are routinely delivered upon, might be willing to wait a few more minutes, confident that he will get that second treat.

So maybe all those years I wasted bouncing between careers in my 20s and 30s weren’t my fault, after all. Maybe my mother just wasn’t reliable enough when I was little. Maybe I sneak scoops of ice cream after my wife goes to bed because I’m still re-enacting the painful experience of losing out on childhood treats I felt were rightfully mine. Or — I’m going out on a limb here — maybe I’m putting too much faith in the power of a simple social-science experiment to explain complex human behavior.

None of this makes the marshmallow study suspect science. Far from it. The correlations the researchers found are statistically meaningful, if not always overwhelming, but even the landmark 1990 paper cited by Goleman in “Emotional Intelligence” warns against reading too much into its results. And, of course, correlation does not equal causation, so while it may be that those who waited obediently for that second marshmallow were more likely to succeed later in life, that doesn’t mean those children possessed some inherent quality that made them less prone to temptation, which is the most common takeaway from the Mischel findings. As the University of Rochester study suggests, some children may have given up because they simply didn’t believe the researcher would give them that second treat. Or it could be that some of the children were just really hungry that day.

If such quibbles get lost as the study enters the public consciousness, Mischel’s findings may also offer some clues as to why we find his experiment so intellectually beguiling. When he first began handing out marshmallows to 4-year-olds, Mischel wanted to understand how some of them could delay gratification and some couldn’t and also whether we could teach children to delay longer. What he found was that if researchers gave children tools to distract them from the “hot” stimulus of the marshmallow (how good it tastes) and helped them focus on a “cooler,” more abstract thought, they waited longer. Some children, of course, supplied their own distractions. They kicked the table or sang songs or turned away. But Mischel learned that when the researchers encouraged children to think of the marshmallow as a white cloud or a cotton ball, they were less likely to pop it into their mouths before the adult came back into the room.

But the marshmallow study is itself a classic “hot” stimulus. If it were really true that you could sit a child down, hand her a marshmallow and 15 minutes later be able to predict her SAT score — well, think of all the money you could save in private-school tuition and SAT prep. Stated like that, the proposition sounds absurd, yet the notion that deep within us is a switch that determines the course of our entire lives is so seductive that it’s hard to distract ourselves with the caveats. It’s hard to keep from overextrapolating from a study that drew its subjects from a relatively homogeneous group of children of academics. It’s hard to remember that, even if the marshmallow study and others like it are completely accurate and reproducible across wide ranges of populations, an ability to resist temptation is one factor among many that shapes our lives. Willpower can do only so much for children facing domestic instability, poor physical health or intellectual deficits.


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