Psychologist Walter Mischel developed the “marshmallow test” in the 1960s as a way of studying preschoolers’ ability to delay gratification. Children were left alone in a room, sitting in front of a single marshmallow, and provided with a bell that they could ring at any time to call back the researcher and then eat the marshmallow. But if they could refrain until the researcher came back of her own accord, they would be given two marshmallows. You have doubtless heard of the test: as a seminal experiment that spawned countless research programmes on self-control, it is a staple of works on the topic. Now, with The Marshmallow Test, which combines scholarly argument with self-help tips, policy proposals and anecdotes from his career, Mischel himself joins the fray.
As a postgraduate student in clinical psychology keen to make a difference to people’s lives, Mischel recounts, he thought he could apply some of the concepts he was learning to work he was doing with a group of disadvantaged teenagers. One evening, the teenagers seemed particularly attentive, and before long Mischel spotted that one of them had set the back of his jacket on fire. The concepts Mischel was being taught were irrelevant to these young people, he realised, and this spurred him to pursue a research career that would allow him to help people to improve their lives.
If self-control is a skill that some of us have more of, then how can successful people such as Bill Clinton or Tiger Woods have had such public lapses?
The starting point for his self-control research was his close observation of the children in the marshmallow test. Tactics used by those who succeeded in resisting temptation included closing their eyes, avoiding looking at the treat, repeating aloud that they could have two treats if they waited, pushing the bell away, singing to themselves and even falling asleep. One particularly successful tactic involved distraction. Mischel investigated further and discovered that when the marshmallows were covered, children found it much easier to wait. He wondered if they could use abstraction to similar effect, drawing on Freud’s idea that creating a “hallucinatory image” of objects of desire (for Freud, the mother’s breasts) enabled infants to inhibit the impulse for immediate gratification. Indeed, Mischel found that giving the children a life-sized, realistic photo instead of an actual marshmallow doubled the average time that children waited. It was possible to get the same increase in waiting time when an actual marshmallow was in front of them if they were instructed to use mental abstraction: “imagine it’s a picture; put a frame around it in your head”. What is more, the effect of substituting a picture was reversed if the children were told to make believe that the reward in the picture was real.
He explains these results by invoking the sort of “two systems” hypothesis popularised by Daniel Kahneman in Thinking, Fast and Slow: the idea that the brain has one fast automatic system for decision-making and another slower and effortful one. Mischel connects these to levels of emotional arousal, calling them the “hot” and “cool” systems. Marshmallows have arousing and motivating “hot” qualities, such as being tasty, which make you want to eat them, and other non-emotional cognitive “cool” features, such as being white and soft. Arousing the hot representations automatically triggers the action of eating the marshmallow, whereas cool representations support the system involving cognitive processing, which enables delay. Changing how you mentally represent a stimulus can change its impact on what you feel and what you do. When Mischel gave up smoking, he observes, he enlisted a memory of a cancer victim being taken for radiation, which he conjured up when he felt a craving.
Nevertheless, it is not always a good thing to be shielded from emotional cues. Self-control can have paradoxical effects. People with high self-control tend to stay calm when making risky decisions, so they are shielded from the stress that people with low self-control feel on making losses. When making a series of risky decisions that are turning out badly, stress and anxiety leads people with low self-control to quit before they go broke. In contrast, under experimental conditions, people who were high in self-control failed to react to danger signals and lost more money than people with low self-control – which Mischel offers as an intriguing explanation for behaviour in the financial sector leading up to the 2008 financial crisis.
Twelve years after the original marshmallow test, follow-up studies revealed that, as adolescents, the children who had waited longer displayed more self-control, had better social and cognitive functioning, and scored higher on intelligence tests. As young adults, they had reached higher educational levels, were less likely to use drugs and had a lower body mass index. Brain scans showed that they had more activity in parts of the brain associated with effective problem solving than those who had not been able to wait.
However, Mischel is at pains to stress that self-control is not genetically predetermined, but can be taught. He is particularly clear on the importance of mindset, the idea that a person’s theory about the possibility of mastery influences how much self-control he or she can actually exert. He cites research by Carol Dweck that shows that if one is to successfully develop self-control, then it is important to think of it as a skill that can be honed and not as an ability that is fixed at birth.
If self-control is a skill that some of us have more of, then how can successful people such as Bill Clinton or Tiger Woods, who must have plenty of self-control in order to achieve their professional success, have had such public lapses? Mischel’s answer builds on his own devastating critique of traditional notions of personality: he proposes that personality consists of “if-then” signatures. These work as follows: someone who is aggressive will not be aggressive in all situations; rather, he or she will be aggressive in response to particular cues. For instance, an aggressive child may be aggressive when other children tease her or when adults punish her. She need not be aggressive in response to all possible cues for aggression, but she will consistently be aggressive in response to particular cues. If those cues occur, then she will exhibit aggressive behaviour. Extrapolating to self-control, it is possible to exercise self-control in many areas of one’s life but to lapse when presented with a specific type of cue, such as sexual temptation. It also follows that it may be valuable to keep a diary in order to learn the cues that lead to destructive behaviours.
The Marshmallow Test is a tour de force. Despite its serious academic content, it wears its learning lightly. Mischel has never been one to shy away from conflict, taking on not only the personality psychologists but also the clinicians to whom he dared to point out that their professional diagnosis was not predictive of which psychiatric patients would be readmitted – instead, the most reliable indicator was the weight of their files. And here, he takes issue with the popular theory of ego depletion, the idea that self-control draws on a limited pool of mental energy. It is valuable for readers to be reminded that science is contested, as popular books frequently give a false impression of consensus.
Although Mischel’s experiments have become justly famous, it has been largely through the popularising work of other people. It is to be hoped that this book will make him as much of a household name as his marshmallows are.
In 1938, the eight-year-old Walter Mischel – today the Robert Johnston Niven professor of humane letters in the department of psychology at Columbia University – fled Nazi-occupied Vienna with his family for the US. His parents opened a shop in Brooklyn, and Mischel studied psychology at New York University and then Ohio State University.
His first paper detailing the “marshmallow test”, conducted at Stanford University’s Bing Nursery School, was published in the Journal of Personality and Social Psychology in 1972. Mischel then moved on to other subjects, thinking, as he recalled in a recent interview, that “there are only so many things you can do with kids trying not to eat marshmallows”. But serendipitous follow-up research led to papers in Science (1989) and Developmental Psychology (1990), and informed countless studies by others.
Indeed, as Michael Bourne noted in The New York Times, the marshmallow test is not only a tale that “captured the public imagination because it is a funny story, easily told”, but is also an object of fascination academy-wide. “If you doubt the ubiquity of the Mischel study,” said Bourne, “try this simple experiment: put a few social-policy geeks in a room and ask them about willpower, then see how long it takes before somebody brings up the four-year-olds and then the marshmallows. My bet is you wouldn’t have to wait more than a minute.”
Mischel sees the studies not as predictors of later success or failure, but as clues to self-improvement strategies. He told the New Yorker, “What we’re really measuring with the marshmallows isn’t willpower or self-control. It’s much more important than that. This task forces kids to find a way to make the situation work for them. They want the second marshmallow, but how can they get it? We can’t control the world, but we can control how we think about it.”
The Marshmallow Test: Understanding Self-control and How to Master It
By Walter Mischel
Bantam, 336pp, £20.00 and £11.98
ISBN 9780593071311 and 97814481542 (e-book)
Published 25 September 2014
Walter Mischel's study into impulse control began in the 1960s. He created what he called his "Surprise Room" at Stanford University's creche (amazing how sinister that sounds now). There, he tested pre-school kids on their self-control. It was simple: they could have one marshmallow immediately, or wait, alone in a room, for a given number of minutes, ring a bell and the researcher would give them two.
The results were astonishing to the team: good impulse control turned out to be a predictor of success in disparate areas, from academic results to health in later life. We have become used to the truth of this: deferred gratification enables the fulfilment of long-term goals; it is so commonplace an observation that you might find it in a fortune cookie or a posh Christmas cracker. So Mischel's description of the research team's surprise struck me as a little overdone, until I remembered that he was the one behind the results that we now hold as truisms. After that, his irksome habits in this book seemed less important. It is undeniable that he is not sceptical enough, but considering the impact he has had on psychological and criminological terrain, the humility in his tone is much more notable than his writing's longueurs.
To call Mischel the trailblazer would be to airbrush out the work of Freud, who intuited pleasure deferral as a component of self, a marker of increased maturity, in 1911. His argument was that the infant created a mental, "hallucinatory" image of the object of desire; the child's libidinal or sexual energy was directed at this hallucinatory image. Such a visual representation allowed "time-binding"; it enabled the infant to delay and temporarily inhibit the impulse for immediate gratification.
Mischel's is a much more practical approach than Freud's – his concern is with the lived experience of impulse control, the moment of failure, the moment of success, what can be learned and what unlearned. His first distinction is between "hot" responses to stimuli – dominated by the limbic system and irresistible – and "cool" responses, led by the pre-frontal cortex and eminently resistible. Think, if you've ever been a smoker, of that moment when you crumble: it is not when you conjure up the image of a cigarette, its size, shape and colour (these are supplied by your pre-frontal cortex, to help you distinguish between a cigarette and a straw); rather, it is when you imagine the way it hits the back of your throat, engulfs your breath with delicious smoke (that was my amygdala talking). Children who can be persuaded to think of marshmallows as puffs of cloud are more likely to overcome their temptation than children encouraged to think of the squidge and the sweetness. But, as per Freud's observations, children who were able to imagine the marshmallow with a frame around it, as an image rather than the thing itself, found it easier to defer gratification, too. Children who distracted themselves performed better. Hot and cool perception interlace with abstraction and diversion to create the person who, down the line, when you've seen their Sats scores and healthy internal organs, you'd call more "rounded".
Mischel references fMRI scans without sufficient caveat; where there is activity in the "stranger" area rather than the "self" area of the brain, that doesn't necessarily mean the subject is thinking of his or her future self as a stranger. The process isn't that fine-tuned. In its current stage, fMRI scanning has been likened to trying to discover what's going on in an office by looking at whether or not it has its lights on. We are a long way from being able to tell what a person is thinking about. The argument about self-perception, however – how different you perceive your future self to be from your current self, and what this says about your ability to save for the future or go to the gym – is interesting. If you can conceive of the future as a real place, this not only engages your "willpower", but also your ethical centre – respondents who identified themselves closely with their future selves were less likely to condone fraud and theft. Illustratively, Mischel suggests a technique for decision-making that involves bringing that future point, whatever it is, to now: how would you feel about x future job if you were to do it today? Or, in the opposite way, how do you feel about x argument or y love affair if you regarded it as a fly on the wall would, rather than immersing yourself in it?
These are relatively simple exercises, yet enlightening: trying to consciously embody the future makes you realise how distantly you really conceive of it, while stepping out of the self enables the cool appraisal that can dissipate heightened emotion. Though I think I'd already read the first advice in a Nancy Mitford novel (when you get an invitation to cocktails, you must always think: would I say yes if it were about to happen today, in half an hour?).
One of the core strategies in this thinking is the "if-then", a framework of encouraging self-talk that even young children concoct for themselves. "If x temptation occurs, then I'll embark on y strategy … It sounds simple, and it is. By forming and practising implementation plans, you can make your hot system reflexively trigger the desired response, whenever the cue occurs. Over time, a new association or habit is formed." This is a strategy of cognitive behavioural therapy; its close sibling is "thought-stopping" (used for anxiety disorders, where the problematic thought is replaced with a pleasurable one, until the two become automatic). A prison psychologist told me once that he'd tried it on a heroin addict; it hadn't worked, because the prisoner had replaced his temptation, heroin, with a pleasurable thought that was also heroin.
At the centre of all this is a sincerely held belief that the answer is within you – that if you can modify your hot animal with your cool reason, if you can strategise against any temptation, if you can conceive of yourself as a striver rather than a finished product, then yours is the world and everything that's in it. (Except, that is, for the things that are addictive or may negatively impact on you in some other way.) It's rather an atomised view of us all – batting away our demons in our own personal video game. But it's fascinating and often horribly recognisable.
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