Stanford marshmallow experiment
Encyclopedia
Deferred gratification
Deferred gratification and delayed gratification denote a person’s ability to wait in order to obtain something that he or she wants. This intellectual attribute is also called impulse control, will power, self control, and “low” time preference, in economics...
conducted in 1972 by psychologist Walter Mischel
Walter Mischel
Walter Mischel is an American psychologist specializing in personality theory and social psychology. He is the Robert Johnston Niven Professor of Humane Letters in the Department of Psychology at Columbia University.-Early life:...
of Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
. A marshmallow
Marshmallow
The marshmallow is a confection that, in its modern form, typically consists of sugar, corn syrup, water, gelatin that has been softened in hot water, dextrose, vanilla flavourings, and sometimes colouring, whipped to a spongy consistency. Some marshmallow recipes call for egg whites...
was offered to each child. If the child could resist eating the marshmallow, he was promised two instead of one. The scientists analyzed how long each child resisted the temptation of eating the marshmallow, and whether or not doing so had an effect on their future success. Although the experiment has been repeated many times since, the original study at Stanford has been considered "one of the most successful behavioural experiments".
Origins
The experiment has its roots in an earlier one performed on TrinidadTrinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
, where Mischel noticed that the different ethnic groups living on the island had contrasting stereotypes of one another, specifically, on the other's perceived recklessness, self-control, and ability to have fun. He performed an experiment similar to the marshmallow experiment, albeit with a chocolate bar, and discovered that ethnicity did not affect deferred gratification at all, while social and economic backgrounds did.
Stanford experiment
The purpose of the original study was to understand when the control of deferred gratificationDeferred gratification
Deferred gratification and delayed gratification denote a person’s ability to wait in order to obtain something that he or she wants. This intellectual attribute is also called impulse control, will power, self control, and “low” time preference, in economics...
, the ability to wait to obtain something that one wants, develops in children. The original experiment took place at the Bing Nursery School located at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, using children the age of four to six as subjects. The children were led into a room, empty of distractions, where a treat of their choice (Oreo
Oreo
Oreo is a trademark for a popular sandwich cookie by the Nabisco Division of Kraft Foods. The current design consists of a sweet, white filling commonly referred to as 'cream' or 'creme', sandwiched between two circular chocolate or golden cookie pieces....
cookie, marshmallow, or pretzel stick) was placed on a table, by a chair. The children could eat the marshmallow, the researchers said, but if they waited for fifteen minutes without giving in to the temptation, they would be rewarded with a second marshmallow. Mischel observed as some would "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", while others would simply eat the marshmallow as soon as the researchers left.
In over 600 children who took part in the experiment, a minority ate the marshmallow immediately. Of those who attempted to delay, one third deferred gratification long enough to get the second marshmallow. Age was a major determinant of deferred gratification.
Follow-up studies
It was the results of the follow-up study that would take place many years later that surprised Mischel. Since Mischel's daughters knew and grew up with many of the original test subjects, through casual conversation, Mischel discovered there existed an unexpected correlation between the results of the marshmallow test, and the success of the children many years later. The first follow-up study, in 1988, showed that "preschool children who delayed gratification longer in the self-imposed delay paradigm, were described more than 10 years later by their parents as adolescents who were significantly more competent". A second follow-up study, in 1990, showed that the ability to delay gratification also correlated with higher SAT scores.A 2011 study of the same participants indicates that the characteristic remains with the person for life. Additionally, brain imaging showed key differences between the two groups in two areas: the prefrontal cortex
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
(more active in high delayers) and the ventral striatum
Ventral striatum
The ventral striatum is generally considered that part of the striatum that is connectionally associated with limbic structures, such as the amygdala, hippocampus, midline thalamus, and certain regions of the prefrontal cortex...
(an area linked to addictions).
A 2006 paper to which Mischel contributed reports a similar experiment, this time using cookies and a computer-controlled go/no-go test. From the study:
[...] the present findings suggest that an effective attentional control system, as reflected in preschoolers’ ability to direct attention away from tempting aspects of the rewards in a delay-of-gratification task, may share a common mechanism with, or serve as a precursor for, long-term ability to inhibit attentional and behavioral responses, as reflected years later in performance on the go/no-go task. Moreover, because inefficient performance in the go/no-go task has been well documented as being associated with immature development of fronto-striatal and related circuitry, the findings suggest that temptation focus in the delay-of-gratification task at age 4 may already be a marker of the subsequent development of individual differences in this system in adolescence and adulthood.
External links
- "Joachim de Posada says, Don't eat the marshmallow yet" from Ted TalkTED (conference)TED is a global set of conferences owned by the private non-profit Sapling Foundation, formed to disseminate "ideas worth spreading"....
- 1972 article –