In 1968, Walter Mischel set a group of children at Bing Nursery School in California a challenge. A researcher offered each of them a marshmallow and then left them alone in a room. If they could resist eating the marshmallow until the researcher returned, up to 15 minutes later, they would be given a second sweet. Mischel, a clinical psychologist, wanted to understand how children acquire self-control. Mischel’s daughters, aged three, four and five at the time, also attended Bing. Over the following years, when he chatted to them about their classmates, Mischel began to notice an interesting pattern: the children who had exhibited the most restraint in the “marshmallow test” were outperforming their peers. He decided to investigate further.
For more than 40 years, Mischel followed the lives of the nursery students. His findings were extraordinary. It turns out that being able to resist a treat at the age of five is a strong predictor of success: you are more likely to perform well at school and report high self-worth and less likely to become obese, develop addictions or get divorced.
“This kind of longitudinal work requires longevity as well as persistence, so I’m very fortunate I’ve been able to follow it through,” Mischel tells me when we meet in a central London hotel. Mischel is 84, though he looks at least a decade younger, and when he laughs, which is often, his expression is almost boyish. He still teaches psychology at Columbia University and has just written The Marshmallow Test, a book summing up half a century of research.
In recent years, the marshmallow test has gained popular appeal, yet in the 1960s his work was unfashionable. Psychologists such as Timothy Leary were experimenting with the therapeutic use of magic mushrooms and LSD. “The ‘tune in, drop out’ counterculture was developing and graduate students’ desks were being replaced with mattresses with burn holes,” he recalls. “So it was an interesting environment to study self-control, given the striking absence of it.”
Mischel says his interest in psychology was first inspired by Sigmund Freud, who lived just a few streets away from his childhood home in Vienna. After the 1938 Anschluss with Nazi Germany, Mischel’s family, which was Jewish, no longer felt safe in Austria. He has only vague memories of watching family members burn their documents and the moment he made a discovery that saved their lives. “[The] family tale has it that I saw a piece of paper that had a very nice gold seal on it that looked very appealing. It turned out to be my maternal grandfather’s American citizenship certificate.”
The certificate allowed the Mischels to travel to the US. They settled in Brooklyn, where they opened a “five cents, ten cents and up store”. Business was never good and Mischel believes the experience of moving from “upper middle class to extreme poverty” shaped his outlook. He is concerned with trying to reduce the impact of deprivation on an individual’s life chances. The conclusion he draws from his marshmallow research is positive: some people may be naturally disciplined but the ability to delay gratification is a skill that can be taught. Teach children self-control early and you can improve their prospects.
I suggest to Mischel that his work could be the ultimate marshmallow test, given that it took decades to see results. Does self-control come easily to him? Not at all, he says, describing his battle to quit smoking by inhaling from a can of stale cigarette butts each time he felt a craving. “I have great difficulties in waiting,” he confesses. “It’s still difficult to wait in a bank line.”