The children who persisted in the Marshmallow Test could…
The children who persisted in the Marshmallow Test could not have done it without their well-developed EF - their executive function. A second critical ingredient for their success was the motivation to sustain their effort, or grit. For what must have felt like eternity, they kept using their minds and imaginations, shifting their attention, and waiting for the adult to come back without ringing the bell.
— from Who Is Flying (Self, Nature & Nurture)