Imagine that you’re 4 years old and that it’s 1968.
You’re brought into a small room, a “game room,” with a table, chair and three sugary snacks. You’re asked to pick one treat. You choose the marshmallow. Then you’re told that you can either have the marshmallow right away by ringing a bell, or wait a few minutes and get two marshmallows. Then you’re left alone for 15 minutes.
This seemingly simple experiment conducted by Austrian-born clinical psychologist Walter Mischel at Stanford University became known as “The Marshmallow Study.” But don’t let the silly name fool you. This study tested over 600 kids at the Bing Nursery School and has become one of the longest-running studies in psychology.
What Mischel actually wanted to explore had zero to do with kids’ desire for sweets, of course. The lead investigator wanted to test the concept of delayed gratification.
He found that a few kids ate the marshmallow as soon as the researcher left the room. Most waited an average of less than three minutes to consume the marshmallow. But a third used various ways to distract themselves and waited the full 15 minutes. Kids did everything from covering their eyes with their hands and turning around to singing songs from “Sesame Street” and playing hide and seek under the desk to tugging at their pigtails.
While this was fascinating on its own, Mischel would make an even more powerful discovery. Mischel’s daughters also attended the Bing Nursery School. From time to time, he’d ask how their classmates — his subjects — were doing.
He began noticing an interesting pattern, which prompted him to conduct followup research, revealing just how this seemingly simple study was anything but.
According to this piece in the New Yorker by Jonah Lehrer, Mischel mailed out questionnaires to the parents, teachers and academic advisers of the study subjects. The questionnaires requested information on the kids’ abilities to plan, think ahead, cope effectively and get along with others, among many other behaviors and traits. He also wanted to know their SAT scores. Lehrer summarizes Mischel’s findings, which basically revealed that the kids who rang the bell right away weren’t doing so great.
Once Mischel began analyzing the results, he noticed that low delayers, the children who rang the bell quickly, seemed more likely to have behavioral problems, both in school and at home. They got lower S.A.T. scores. They struggled in stressful situations, often had trouble paying attention, and found it difficult to maintain friendships. The child who could wait fifteen minutes had an S.A.T. score that was, on average, two hundred and ten points higher than that of the kid who could wait only thirty seconds.
The inspiration for studying self-control in American kids actually came from an unlikely source: another country. In 1955, Mischel, who was initially interested in psychoanalysis and the Rorschach test, traveled to Trinidad to study one culture’s spirit possession ceremonies. But he changed his mind after noticing the dynamics between two groups of people — those of East Indian descent and those of African descent — and started studying something else entirely. According to Lehrer:
Although his research was supposed to involve the use of Rorschach tests to explore the connections between the unconscious and the behavior of people when possessed, Mischel soon grew interested in a different project. He lived in a part of the island that was evenly split between people of East Indian and of African descent; he noticed that each group defined the other in broad stereotypes. “The East Indians would describe the Africans as impulsive hedonists, who were always living for the moment and never thought about the future,” he says. “The Africans, meanwhile, would say that the East Indians didn’t know how to live and would stuff money in their mattress and never enjoy themselves.”
Mischel took young children from both ethnic groups and offered them a simple choice: they could have a miniature chocolate bar right away or, if they waited a few days, they could get a much bigger chocolate bar.
His research didn’t end up substantiating the stereotypes. But it did bring up important questions about delayed gratification, such as why some kids waited to eat the chocolate bar, while others didn’t.
Mischel also realized that he could actually measure self-control. This was important because at the time most psychology tests, including personality measures, weren’t exactly valid or reliable. After reviewing the literature and using the personality measures in his own work, Mischel realized that the underlying theories were the problem. The measures were created with the assumption that personality was stable across situations. But Mischel found that context was key.
His goal was to conduct rigorous scientific research with measurable variables — and his earlier straightforward setup of sugary snacks in Trinidad provided a great place to start.
Be sure to read the rest of Lehrer’s article, which discusses the advanced methods that Mischel and other researchers are using to study self-control today. For instance, they’re using fMRI machines to explore the brains of the original subjects.
Also, check out this excellent podcast on BBC where Claudia Hammond interviews Mischel and his colleagues. Here, Mischel cautions against using his research to predict the fate of individual kids. He notes that these are group differences, and shouldn’t be misinterpreted as a fortune cookie that dooms one child but blesses another.
(By the way, I know it’s tempting to want to apply these findings to dieting and restricting certain foods like desserts. Unfortunately, nowadays, self-control typically gets associated with such things. However, many studies show that restricting yourself actually leads to overeating. As author of Weightless, a blog that helps people improve their body image and ditch dieting, you know where I stand.)