Psychologist revisits his iconic 'marshmallow test,' 4 decades later

Between 1968 and 1974, more than 600 students at Bing Nursery School in Palo Alto, Calif., took part in the "marshmallow test," one of the most famous studies in psychology. The "test" was the brainchild of psychologist Walter Mischel, then of Stanford University, who set out to understand how children develop the ability to delay gratification, a critical skill for success in life.

In the "surprise room" of the university's laboratory nursery school, a 4-year-old was offered the choice of a cookie, pretzel stick or marshmallow. The researcher would then place the treat in front of the child — we'll assume the marshmallow is chosen — saying, "You can have this one marshmallow any time you want it, but if you don't eat it and wait until I return, then you can have two." The researcher then left the room for 15 minutes.

About a third of the children immediately ate the marshmallow. Another third waited (an average of 3 minutes), singing to themselves, approaching their marshmallow, sniffing it, then rearing back as if it were dangerous — and then eating it. The final third fidgeted, grimaced, danced in their seats — one girl even napped — but waited the seemingly endless 15 minutes until the researcher returned and they could have the two marshmallows.

It was the results from a series of follow-up studies of the original participants that entrenched the "marshmallow test" as the paradigm for self-control, the subject of TED Talks, YouTube videos, and some further adventures of Sesame Street's Cookie Monster.

Later in life, the research found, the "waiters" were thinner, handled stress better, enjoyed better friendships, had more grit, fewer substance abuse problems, and higher SAT scores than the "grabbers."

Now, Mischel has gathered his entire body of research on resisting the siren song of temptation in a new book, "The Marshmallow Test: Mastering Self-Control" (Little, Brown and Co.). The book is part science — outlining the history of the test and the impact of factors like gender, age, trust and stress on self-control, and part self-help — detailing the strategies children and adults can adopt to exercise willpower over "marshmallows," to accomplish goals such as quitting smoking, saving for retirement and even overcoming heartbreak. Following is an edited version of our conversation:

Q: What was it in your own experience that led you to study self-control?

A: I was beginning my work as a young professor at Stanford, and I saw what looked like a miracle unfolding in front of me at the kitchen table with my three daughters. They were going through this huge developmental change that occurs from birth to about age five, where kids begin spontaneously to have many of the skills that are required for self-control and delay of gratification.

I realized I didn't have a clue about what was going on in their heads, and what it was that enabled them to do this. Will they have the cognitive skills, and the persistence, the grit, that is required to actually delay gratification and resist temptations and do the waiting for the things that they want? I feel to this day that's probably the most central question for understanding what the human potential is for helping people to be able to be active agents in shaping, at least in part, how their lives evolve.

Q: In capturing the imagination of the public, you've said that the test and its results have been "endlessly distorted." Should your book come with a warning label "Don't try this at home," so parents stop administering it at the kitchen table to figure out if they've got a "grabber" or a "waiter"?

A: The relationship between seconds of delay and long-term life outcomes are impressive, but not nearly strong enough to believe that how long you wait on the marshmallow test is a measure of your destiny. It isn't. There is no question that lots of kids who don't wait long on the marshmallow test at all, who even grab it early, have lives that are perfectly wonderful. And lots of kids who are good waiters can under many circumstances wind up with all kinds of problems. It's a mistake to think that you either have this skill or you don't have it, because it's a skill that is eminently teachable.

Q: How are the two sides of the brain — the limbic-hot system that is impulsive and wants immediate gratification and the cool-cognitive prefrontal cortex that is smarter, rational and able to take delayed consequences into account — key to self-control?

A: The secret to self-control, whether it's eating or smoking or temper in emotional relationships, is to cool the hot system sufficiently so that the cool system can snap into place, because then individuals are able to think constructively and from a bit of a distance, rather than automatically and reflexively. If I'm trying to give up smoking, I have to focus on what it would be like to get that X-ray in which the doctor is showing me the black spot on my lungs, and is saying, "I'm sorry, it has metastasized." For people who are having huge troubles resisting the fudge cake for dessert, all they have to do is imagine that a cockroach had a little bite of it in the kitchen before it came out, and the desire goes away.

Q: What are some of the strategies parents can use to teach their children self-control?

A: Model it yourself. If you have high standards for when you reward your own behavior and when you hold back on rewarding your own behavior until you've met certain criteria, children will see that and model it.

But let me give you another concrete example. The key to self-control and self-regulation is how the temptation is mentally represented or thought about. What if I say to that little girl, "If you want to, while you're waiting for those two cookies, you can make believe that they're not real — make believe that it's just a picture — put a frame around it in your head." Now, with that tool, I've seen children wait 15 minutes.

Q: It seems like Americans are in a constant state of immediate gratification. What have you seen, and what is the data telling you?

A: It's a very widespread belief that society is having a harder and harder time delaying gratification. It's actually a question that we're studying, and we'll have some answers to it and I predict they're going to be very surprising.

But what the information-technology revolution has done is provide us with an enormous number of instantly available ways of getting answers, getting responses, getting gratification. So there is a huge change not in individuals, but in the environment of immediate temptations, of "buy buttons," that are available to us. So we are living in a world with an array of temptations that were inconceivable at the time that the marshmallow studies began. I don't think that there's a decrease in the skills that are needed for self-control. There is an increase in the temptations.

Q: And the most important lesson learned from the "marshmallow test"?

A: Learning when you want to eat the marshmallow is just as important as developing the skills that allow you to resist the marshmallow. A life lived with too much delay of gratification can be as sad as one without enough of it.

This article originally appeared in the Chicago Tribune on October 22, 2014.