A 1972 study known as the “marshmallow test” was developed to gauge children’s ability to delay gratification of their desires. The kids were offered a single marshmallow to enjoy but were told if they could refrain from eating it for ten minutes, they’d be given a second one. About a third of the children were able to hold out for the larger reward (another third gobbled it up within thirty seconds!).

We might struggle to show self-control when offered something we desire, even if we know it would benefit us more in the future to wait. Yet Peter urges us to…