Have you heard of the marshmallow study? Between 1968 and 1974, about 650 4-year-olds in a nursery school at Stanford were offered a selection of marshmallows, cookies, and pretzels. After they chose one (let’s say it was the marshmallow, though I’d have picked a cookie myself), they were told they could either eat it immediately, or wait a few minutes and get two. The researcher giving the kids this choice then left the room. The kids tried to wait. As Jonah Lehrer describes (I know, I know, but this piece is in The New Yorker so it was fact-checked), “Some cover their eyes with their hands or turn around so that they can’t see the tray. Others start kicking the desk, or tug on their pigtails, or stroke the marshmallow as if it were a tiny stuffed animal.”
Most of the kids lasted less than three minutes, on average. But about 30 percent waited 15 minutes for the researcher to come back and give them their second marshmallow. “These kids wrestled with temptation but found a way to resist,” Lehrer writes. And over the years, it has turned out that the kids who knew how to delay gratification at age 4 tended toward higher SAT scores and social competence. As a group, they were better at planning and handling stress. And now a new study shows that all the way into adulthood, they are also less likely to be overweight or obese.
Tanya Schlam at the University of Wisconsin School of Medicine and Public Health and colleagues followed up with the former preschoolers, who are now in their 30s. Schlam (whom I know) found that each minute that the subjects delayed gratification as children predicted a 0.2 point decrease in their current body mass index. “Although the effect was not particularly large, the presence of any effect three decades later is noteworthy,” she argues. That’s especially true because other research suggests kids can be taught to delay gratification. “Some educational approaches (like Montessori) focus on teaching kids self-control and have high expectations for self-regulation from an early age so kids get lots of practice and improve over time,” Schlam explained in an email.
Delayed gratification is related to the elusive quality of will power, but it’s framed to be attainable. “It involves being more strategic,” Schlam wrote to me. “So a child can use will power to delay gratification, but they have a lot of other techniques at their disposal that they can combine with using will power. For example, from studies with this sample, we know that when the marshmallows are hidden by a tray or when the experimenter tells the kids to think about the marshmallows as ‘fluffy white clouds,’ the kids are able to delay much longer.” Kids who picked up the marshmallow and smelled it, on the other hand, soon gobbled it up. Delayed gratification, then, is about “knowing intuitively or being taught techniques that enable your cool system to kick in (which is reflective and rational) rather than the hot system (which is reflexive and impulsive).”
Schlam points out that the best route to self-control is to avoid having to exercise it: to stay away from trays of marshmallows and cookies. But since we live in a world of too much food, it’s a comfort to know that we can teach kids to hold back on their own. Even kids whose reason for delaying gratification is that they want a second marshmallow.