Today we are going to step into the time machine and go back 21 years to 1989. It was in this year that the study to become known as the ’Marshmallow experiment’ was published. Performed by Walter Mischel at Stanford University this experiment showed an amazing thing, that testing a child’s self-control at 4yrs could predict academic success later in life.
The numerous experiments actually entailed in this study started with the same basic premise. Children were told that they could obtain a small reward immediately or could hold out for a more valuable reward later. The rewards were carefully calibrated to produce conflict in the child over whether to go for the immediate reward or wait for the larger reward (eg one marshmallow vs two, hence the name of the experiment). The experimenter would then leave the child alone and return a short (although not for the child) time later, typically about 15 minutes. The child could ring a bell at any time to recall the experimenter and receive their lesser reward.
Over a series of experiments the researchers examined what strategies were most effective at helping the child to delay their own gratification the longest. In some situations the rewards were fully visible, allowing the children to see only the immediate reward, only the delayed reward or both. In others the rewards were present in the room but hidden. We might find it obvious but those children who could see the rewards could not wait as long as those that had the rewards hidden.
It’s important to remember here that while some of the conclusions of the study seem obvious in hindsight (and possibly to anyone with young children) previous theories of the ability to delay gratification have considered the ability to conceptualise rewards instrumental to being able to to inhibit impulsivity. To explore this hypothesis then the researchers primed the children with various thoughts prior to the experiments, either by encouraging the children to think about the rewards or by giving them other fun things to think about.
The findings showed that how the child thought about the rewards significantly impacted how long they waited, whether or not the rewards was sitting in full display in front of them. Those children that were distracted by the fun thoughts could hold out longer than those who ere primed to think about the rewards.
To examine this further children where then primed to think about the rewards in different ways. Those who were told to think about what were termed ’arousing’ properties of the rewards, for example the texture and taste of a food reward, had much more difficulty delaying than those who were directed to think about the abstract qualities of the reward. Indeed, those children who were told to imagine real rewards were only pictures of the objects did much better than children who were told to imagine that pictures of the rewards were real.
One of the best strategies found by the study was for the child to imagine the arousing properties of a different food to the one they would get as a reward, eg thinking about the taste of pretzels while waiting for marshmallows.
So far so good, here’s where the real surprising aspect comes, in a follow-up to these experiments children from the original studies were then looked at more than ten years later to see if the ability to delay self gratification had effects later in life. They authors predicted that differences in the ability of children to delay when they had been given no strategies to help them (eg hiding the rewards) would perform better later in life than those who had the rewards removed from sight. This prediction turned out to be upheld, those students who could had been able to delay their own satisfaction without external help had higher test scores and were described by their parents as, to quote the study:
“more verbally fluent and able to express ideas; they used and responded to reason, were attentive and able to concentrate, to plan, and to think ahead, and were competent and skillful. Likewise they were perceived as able to cope and deal with stress more maturely and seemed more self assured.”
The results of this study seem to imply that those individuals who are able to spontaneously generate strategies to aid them in planing for and achieving future rewards are better equipped to deal with life. Hhmm, when I put it that way it seems obvious, I have to point out though that it is only through experiments and observations such as this that these conclusions become obvious. Without the ability to identify the ability of children to employ coping strategies themselves there would have been no basis upon which to predict this outcome.
Congratulations, you’ve made it to the end of this post, here’s a reward. An amusing video featuring a re-creation of the original experiment showing children in the sweet agony of indecision.
Mischel, W., Shoda, Y., & Rodriguez, M. (1989). Delay of gratification in children Science, 244 (4907), 933-938 DOI: 10.1126/science.2658056