Who would think that a marshmallow could cause such distress?

But here we see how young children struggle to resist the urge to eat a delicious treat. In a famous experiment, researchers put a marshmallow in front of children and told them that they could either eat it or wait; and if they waited for a certain amount of time to eat the first marshmallow, they would get a second one. The researchers then left the room while the children were filmed. Some gave in and immediately gobbled down the marshmallow, some waited a little while, and some held out for the entire time for the reward of a second marshmallow.

Walter Mischel, the psychologist who devised this experiment, was interested in the strategies children use to resist such temptations. The children who made it to the end could be seen deliberately turning away from the tasty morsel. When they were asked afterwards how they had managed to wait, one of several reported strategies was imagining the marshmallow to be something else, such as a fluffy cloud, which reduced their desire for the treat.

What self-control in childhood means for later success

It was almost by chance that Mischel later discovered the power of the ability to delay gratification. Some of the participants in his first experiments were friends of his children. Years later, when his children left home to go to college, they would report on what their friends were doing. Mischel noticed that the children who had been able to wait the longest in his marshmallow experiment were also the ones who scored highest on the SATs, the standardised test widely used in US college admissions.

“Developing self-control is about learning to pursue the goals set by both oneself and others.”

After further study, Mischel discovered that children’s ability to delay gratification was a better predictor of later SAT scores than their intelligence at the time of testing. And just as self-control at an early age can predict positive outcomes, such as academic achievement, it is clear from other studies that poor self-control early in life is associated with potentially disastrous outcomes. A seminal study by Terrie Moffitt showed that the weaker children’s self-control was early in life, the lower their earnings, the worse their health and the greater their chances of engaging in substance abuse and criminal activity 32 years later.

Can we improve self-control during childhood?

Inhibition and self-control are among a cluster of cognitive skills known as executive functions. Executive functions are required for bringing behaviour in line with one’s long-term goals. Given that self-control early in life plays such an important role in productive development, there has been considerable interest in trying to improve this ability in children. The brain undergoes important structural and functional changes during childhood, so children may be particularly sensitive to interventions that train self-control.

One of the key questions is whether laboratory training will result in changes in other functional domains and in real life. Studies aimed at improving children’s self-control have concentrated on their ability to control their motor impulsivity. This, however, has not led to transfer effects in other domains. Because efforts to improve other executive functions that are unrelated to self-control, such as working memory, have produced improvements as well as transfer effects, some believe that self-control may be untrainable.

This conclusion is premature, in my opinion. A great deal of attention has recently been paid to the question of when training might be expected to produce transfer effects. The consensus is that training must become increasingly difficult to improve a skill and generate transfer effects – no pain, no gain.

Moreover, to produce transfer effects in other domains and across a variety of situations, training must be sufficiently complex, novel and diverse. So far, self-control training has not paid enough attention to all these features. My work attempts to create training regimens that satisfy each of these criteria, in an effort to determine whether self-control can indeed be improved and what the long-term consequences of such improvements might be.

Self-control outside the lab

But are structured interventions the only way to improve self-control? A recent study showed that the more children engaged in unstructured activities, such as free play, whether alone or with others, the better their self-directed executive functioning. This suggests that giving children more opportunities to structure their daily activities and allowing them to make their own decisions and learn from their mistakes might improve specific aspects of their self-control.

Sadly, we see fewer and fewer of these opportunities in children’s everyday lives. Parenting is becoming an increasingly “dangerous” business, with an entire industry pandering to parents’ fears – of accidents, strangers or their own ineptitude. This threatens to produce a generation of coddled children with fewer chances of exploring the world and learning from their own mistakes along the way.

Developing self-control is about learning to pursue the goals set by both oneself and others. Parents can assist in this process by choosing the right times to support children’s choices and remind them of their goals, while knowing when to refrain from interfering.

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