Forty years after a groundbreaking Stanford behavioral experiment, three Cornell researchers revealed consistencies in the human ability to resist temptation from childhood to middle age.
The study, published in the Aug. 29 issue of Proceedings of the National Academy of Sciences of the United States of America, tested cognitive control by presenting 59 test subjects with a variety of faces and recording their responses to those stimuli. Functional magnetic resonance imaging was also used during the trials to examine subjects’ brain activity.
The study followed up with the subjects of the original Stanford marshmallow tests — conducted by Dr. Walter Mischel in the late 1960s and early 1970s — which tested human ability to delay gratification. Researchers in the original study gave preschoolers the option of eating one marshmallow immediately or waiting approximately fifteen minutes for the researcher to return to the room, at which point the four-year-old would receive an additional marshmallow.
While the original study used marshmallows and cookies, the follow-up replaced those food temptations with social ones, in the form of happy faces. Dr. B. J. Casey, director of the Sackler Institute at Weill Cornell Medical College, said the substitution was a necessary swap.
“Marshmallows and cookies aren’t exactly that compelling and can even be disgusting to older individuals. Smiling faces are almost like a conditioned cue in the environment, a more compelling cue for adults. The response tells us more than if it just has something to do with food,” she said.
The recent study found that the capability to resist gratification, as measured 40 years ago, is a “relatively stable individual difference characteristic,” according to the PNAS article. The subjects who were low-delayers, who chose to eat the first marshmallow immediately in preschool, exhibited a similar lack of delaying abilities in their mid-forties. The high-delayers, who waited for the second marshmallow, also tested similarly in their ability to delay gratification later in life.
Additionally, researchers found that cognitive control was not the fundamental determinant of ability to resist temptation. In fact, the type of stimulus — how compelling or salient it is — plays a critical role in the way people respond to cues.
Casey said she was “blown away” by the consistency of the follow-up results with Mischel’s original study.
“The people who couldn’t delay as four-year-olds, when 40, really couldn’t stop themselves from reacting to social cues,” she said. “It’s really shocking 40 years later to see such a consistency in the behavior. A lot happens in life between four and 40.”
Previous follow-up studies on the group of 653 preschoolers from the marshmallow study found that those low-delayers who couldn’t resist the marshmallow had on average lower SAT scores, more behavioral problems and struggled with stress, paying attention and maintaining friendships, according to a New Yorker article. The article also connected higher delay ability with less physical and mental health problems, such as weight struggles, addiction, psychological disorders and divorce.
Casey drew a distinction between the low and high delayers but emphasized that inability to delay gratification is not a fatal flaw. The high delayers who were able to exploit the situation and thus receive two cookies may have been more methodical, but Casey described the low delayers that reacted in the heat of the moment as “explorers, risk takers, pioneers.”