The marshmallow test is simple: a child is given a choice between having one marshmallow now or two marshmallows later.
Forty years ago, a researcher tested the self-control of 4-year-olds by offering them the choice of one marshmallow immediately or two marshmallows 15 minutes later.
In experiments beginning in the late 1960s, the psychologist Walter Mischel tormented preschoolers with the agonizing choice of one marshmallow now or two marshmallows 15 minutes from now.
In the famous Stanford marshmallow experiment, young children were offered one small marshmallow now, or two marshmallows in 15 minutes if they could resist eating the first one.
Some students, when given the choice between eating a marshmallow straight away or waiting to get two marshmallows, could barely contain themselves and ate the first marshmallow.
He told them that they could eat the marshmallow at once, or wait until he came back and get two marshmallows.
She was welcome to eat the one marshmallow while he was gone but, if she could wait until he returned, he would give her two marshmallows.
If they could resist the temptation to eat it, as they were told by the experimenters, they would be rewarded with two marshmallows later on.
All those decades ago, Mischel suspected that, if children were to wait for two marshmallows, they first required an essential belief that their promise would be kept.
If, however, they didn't ring the bell and waited for him to come back on his own, they could then have two marshmallows.
