The End of Average: How We Succeed in a World That Values Sameness

by Todd Rose

Kidd conducted her own version of the marshmallow study, with a crucial twist: she placed one group of children in a “reliable” situation and another group in an “unreliable” situation. Before the marshmallow test began, the kids in the unreliable situation encountered an adult who did not keep his word—for example, during an art project the adult promised the child that if she waited for a little while he would bring her a new set of art supplies to replace her container of broken and well-worn crayons. After a few minutes, he returned empty-handed. The kids in the reliable group, meanwhile, encountered an adult who delivered the new supplies exactly as promised.41 The kids in the reliable situation behaved pretty much like the kids in previous marshmallow studies: a few kids gave into temptation quickly, but about two-thirds of them managed to wait all fifteen minutes—the maximum time. Things were quite different for the kids in the unreliable situation. Half of them devoured the marshmallow within the first minute after the adult departed. Only one child lasted long enough to get a second marshmallow.42 Self-control feels like some kind of essential trait, but Kidd helped show that it, too, is contextual.