The “marshmallow test” is an experiment which measures how much self-control a preschooler has – will they eat one enticing marshmallow now, or will they hold back and wait for the promised two? It is an experiment that has been around for over forty years and is said to reflect how well preschoolers are likely to do later on in life.

Cognitionthe ability to delay gratification is influenced by two things: an innate ability to wait, and the person’s environment

“Our results definitely temper the popular perception that marshmallow-like tasks are very powerful diagnostics for self-control capacity.

Being able to delay gratification – in this case to wait 15 difficult minutes to earn a second marshmallow – not only reflects a child’s capacity for self-control, it also reflects their belief about the practicality of waiting,” says Kidd. “Delaying gratification is only the rational choice if the child believes a second marshmallow is likely to be delivered after a reasonably short delay.”

et al

The unreliable condition group

The reliable condition group

the marshmallow task

“We had one little boy who grabbed the marshmallow immediately and we thought he was going to eat it. Instead he sat on it. Instead of covering his eyes, he covered the marshmallow.”

The unreliable situation group

The reliable situation group

“If you are used to getting things taken away from you, not waiting is the rational choice. Then it occurred to me that the marshmallow task might be correlated with something else that the child already knows – like having a stable environment.”

Proceedings of the National Academy of Sciencesthose who were able to delay gratification remained so, while those who wanted their treat straight away had not changed much either